Science.gov

Sample records for active space scf

  1. A complete active space SCF method (CASSCF) using a density matrix formulated super-CI approach

    NASA Astrophysics Data System (ADS)

    Roos, Björn O.; Taylor, Peter R.; Si≐gbahn, Per E. M.

    1980-05-01

    A density matrix formulation of the super-CI MCSCF method is presented. The MC expansion is assumed to be complete in an active subset of the orbital space, and the corresponding CI secular problem is solved by a direct scheme using the unitary group approach. With a density matrix formulation the orbital optimization step becomes independent of the size of the CI expansion. It is possible to formulate the super-CI in terms of density matrices defined only in the small active subspace; the doubly occupied orbitals (the inactive subspace) do not enter. Further, in the unitary group formalism it is straightforward and simple to obtain the necessary density matrices from the symbolic formula list. It then becomes possible to treat very long MC expansions, the largest so far comprising 726 configurations. The method is demonstrated in a calculation of the potential curves for the three lowest states ( 1Σ +g, 3Σ +u and 3Π g) of the N 2 molecule, using a medium-sized gaussian basis set. Seven active orbitals were used yielding the following results: De: 8.76 (9.90), 2.43 (3.68) and 3.39 (4.90) eV; re: 1.108 (1.098), 1.309 (1.287) and 1.230 (1.213) Å; ω e: 2333 (2359), 1385 (1461) and 1680 (1733) cm -1, for the three states (experimental values within parentheses). The results of these calculations indicate that it is important to consider not only the dissociation limit but also the united atom limit in partitioning the occupied orbital space into an active and an inactive part.

  2. Complete active space (CAS) SCF study of the dipole polarizability function for the X 1Sigma + state of LiH

    NASA Astrophysics Data System (ADS)

    Roos, Björn O.; Sadlej, Andrzej J.

    1982-06-01

    The CAS SCF method is applied to the calculation of the dipole polarizability function of the X 1Σ+ state of LiH by using the finite-field perturbation approach. The dipole moment function and the potential energy curve are also computed. The vibrational averaging of electric properties has been carried out with different accurate potential energy curves available for the LiH molecule. It has been found that the vibrational contribution to the polarizability components leads to the change of the sign of the polarizability anisotropy between the second and third vibrational state. The dipole polarizability tensor transition matrix elements for some of the lowest energy vibrational transitions have been calculated and can be checked against the Raman intensity data.

  3. Stem cell factor (SCF) protects osteoblasts from oxidative stress through activating c-Kit-Akt signaling

    SciTech Connect

    Yang, Lei; Wu, Zhong; Yin, Gang; Liu, Haifeng; Guan, Xiaojun; Zhao, Xiaoqiang; Wang, Jianguang; Zhu, Jianguo

    2014-12-12

    Highlights: • SCF receptor c-Kit is functionally expressed in primary and transformed osteoblasts. • SCF protects primary and transformed osteoblasts from H{sub 2}O{sub 2}. • SCF activation of c-Kit in osteoblasts, required for its cyto-protective effects. • c-Kit mediates SCF-induced Akt activation in cultured osteoblasts. • Akt activation is required for SCF-regulated cyto-protective effects in osteoblasts. - Abstract: Osteoblasts regulate bone formation and remodeling, and are main target cells of oxidative stress in the progression of osteonecrosis. The stem cell factor (SCF)-c-Kit pathway plays important roles in the proliferation, differentiation and survival in a range of cell types, but little is known about its functions in osteoblasts. In this study, we found that c-Kit is functionally expressed in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. Its ligand SCF exerted significant cyto-protective effects against hydrogen peroxide (H{sub 2}O{sub 2}). SCF activated its receptor c-Kit in osteoblasts, which was required for its cyto-protective effects against H{sub 2}O{sub 2}. Pharmacological inhibition (by Imatinib and Dasatinib) or shRNA-mediated knockdown of c-Kit thus inhibited SCF-mediated osteoblast protection. Further investigations showed that protection by SCF against H{sub 2}O{sub 2} was mediated via activation of c-Kit-dependent Akt pathway. Inhibition of Akt activation, through pharmacological or genetic means, suppressed SCF-mediated anti-H{sub 2}O{sub 2} activity in osteoblasts. In summary, we have identified a new SCF-c-Kit-Akt physiologic pathway that protects osteoblasts from H{sub 2}O{sub 2}-induced damages, and might minimize the risk of osteonecrosis caused by oxidative stress.

  4. Space group symmetry applied to SCF calculations with periodic boundary conditions and Gaussian orbitals

    NASA Astrophysics Data System (ADS)

    Rusakov, Alexander A.

    We report theoretical, algorithmic, and computational aspects of exploiting space-group symmetry in self-consistent field (SCF) calculations, primarily Kohn-Sham density functional theory (DFT), with periodic boundary conditions (PBC) and Gaussian-type orbitals. Incorporating exact exchange leads to generally better performance for a broad class of systems, but leads to a significant increase of computation time, especially for 3D solids, due to a large number of explicitly evaluated two-electron integrals. We exploit reduction of the list thereof based on the space-group symmetry of a crystal. As distinct from previous achievements, based on the use of symmorphic groups only, we extend our technique to non-symmorphic groups, thus enabling application of any of 230 3D space groups. Algorithms facilitating efficient reduction of the list of two-electron integrals and restoring the full Fock-type matrix have been proposed and implemented in the development version of Gaussian program. These schemes are applied not only to the HFx, but also to explicit evaluation of the near-field Coulomb contribution. In 3D solids with smallest unit cells speedup factors range from 2X to 9X for the near field Coulomb part and from 3X to 8X for the exact exchange, thus leading to a substantial reduction of the overall computational cost. Factors noticeably lower than the number of the operations are due to the highly symmetric atomic positions in crystals, as well as to the choice of primitive cells. In systems with atoms on general positions or in special positions of low multiplicity, the speedup factors readily exceed one order of magnitude being almost 70X (near-field Coulomb) and 57X (HFx) for the largest tested (16,7) single-walled nanotube with 278 symmetry operations.

  5. Space group symmetry applied to SCF calculations with periodic boundary conditions and Gaussian orbitals

    NASA Astrophysics Data System (ADS)

    Rusakov, Alexander A.; Frisch, Michael J.; Scuseria, Gustavo E.

    2013-09-01

    Space group symmetry is exploited and implemented in density functional calculations of extended systems with periodic boundary conditions. Our scheme for reducing the number of two-electron integrals employs the entire set of operations of the space group, including glide plains and screw axes. Speedups observed for the Fock matrix formation in simple 3D systems range from 2X to 9X for the near field Coulomb part and from 3X to 8X for the Hartree-Fock-type exchange, the slowest steps of the procedure, thus leading to a substantial reduction of the computational time. The relatively small speedup factors in special cases are attributed to the highly symmetric positions atoms occupy in crystals, including the ones tested here, as well as to the choice of the smallest possible unit cells. For quasi-1D systems with most atoms staying invariant only under identity, the speedup factors often exceed one order of magnitude reaching almost 70X (near-field Coulomb) and 57X (HFx) for the largest tested (16,7) single-walled nanotube with 278 symmetry operations.

  6. Parallel SCF adaptor capture proteomics reveals a role for SCFFBXL17 in NRF2 activation via BACH1 repressor turnover.

    PubMed

    Tan, Meng-Kwang Marcus; Lim, Hui-Jun; Bennett, Eric J; Shi, Yang; Harper, J Wade

    2013-10-10

    Modular cullin-RING E3 ubiquitin ligases (CRLs) use substrate binding adaptor proteins to specify target ubiquitylation. Many of the ~200 human CRL adaptor proteins remain poorly studied due to a shortage of efficient methods to identify biologically relevant substrates. Here, we report the development of parallel adaptor capture (PAC) proteomics and its use to systematically identify candidate targets for the leucine-rich repeat family of F-box proteins (FBXLs) that function with SKP1-CUL1-F-box protein (SCF) E3s. In validation experiments, we identify the unstudied F-box protein FBXL17 as a regulator of the NFR2 oxidative stress pathway. We demonstrate that FBXL17 controls the transcription of the NRF2 target HMOX1 via turnover of the transcriptional repressor BACH1 in the absence or presence of extrinsic oxidative stress. This work identifies a role for SCF(FBXL17) in controlling the threshold for NRF2-dependent gene activation and provides a framework for elucidating the functions of CRL adaptor proteins. PMID:24035498

  7. MEK1-independent activation of MAPK and MEK1-dependent activation of p70 S6 kinase by stem cell factor (SCF) in ovarian cancer cells

    SciTech Connect

    Liu, Lian; Zhang, Xin; Du, Chao; Zhang, Xiaoning; Hou, Nan; Zhao, Di; Sun, Jianzhi; Li, Li; Wang, Xiuwen; Ma, Chunhong

    2009-05-01

    We discovered a stem cell factor (SCF)-triggered, MEK1-independent, and PI3K-dependent MAPK activation pathway in the Kit-expressing ovarian cancer cell line HEY. When we knocked down MEK1 with RNA interference (RNAi) to study the function of MEK1 on the proliferation and survival of ovarian cancer cells, we found that impaired cell growth still occurred after MEK1 expression had been suppressed, although MAPK activation remained intact. This suggests that there is MEK1-independent activation of MAPK in the SCF-induced ovarian cancer cell growth process, and that MEK1 still plays a crucial role in maintaining the malignant properties of ovarian cancer cells even when it fails to activate MAPK as expected.

  8. Parallel SCF Adaptor Capture Proteomics Reveals a Role for SCFFBXL17 in NRF2 Activation via BACH1 Repressor Turnover

    PubMed Central

    Tan, Meng-Kwang Marcus; Lim, Hui-Jun; Bennett, Eric J.; Shi, Yang; Harper, J. Wade

    2014-01-01

    Modular Cullin-RING E3 ubiquitin ligases (CRLs) use substrate binding adaptor proteins to specify target ubiquitylation. Many of the ~200 human CRL adaptor proteins remain poorly studied due to a shortage of efficient methods to identify biologically relevant substrates. Here, we report the development of Parallel Adaptor Capture (PAC) proteomics, and its use to systematically identify candidate targets for the leucine-rich repeat family of F-box proteins (FBXLs) that function with SKP1-CUL1-F-box protein (SCF) E3s. In validation experiments, we identify the unstudied F-box protein FBXL17 as a regulator of the NFR2 oxidative stress pathway. We demonstrate that FBXL17 controls the transcription of the NRF2 target HMOX1 via turnover of the transcriptional repressor BACH1 in the absence or presence of extrinsic oxidative stress. This work identifies a role for SCFFBXL17 in controlling the threshold for NRF2-dependent gene activation and provides a framework for elucidating the functions of CRL adaptor proteins. PMID:24035498

  9. Gln40 deamidation blocks structural reconfiguration and activation of SCF ubiquitin ligase complex by Nedd8

    PubMed Central

    Yu, Clinton; Mao, Haibin; Novitsky, Eric J.; Tang, Xiaobo; Rychnovsky, Scott D.; Zheng, Ning; Huang, Lan

    2015-01-01

    The full enzymatic activity of the cullin-RING ubiquitin ligases (CRLs) requires a ubiquitin-like protein (that is, Nedd8) modification. By deamidating Gln40 of Nedd8 to glutamate (Q40E), the bacterial cycle-inhibiting factor (Cif) family is able to inhibit CRL E3 activities, thereby interfering with cellular functions. Despite extensive structural studies on CRLs, the molecular mechanism by which Nedd8 Gln40 deamidation affects CRL functions remains unclear. We apply a new quantitative cross-linking mass spectrometry approach to characterize three different types of full-length human Cul1–Rbx1 complexes and uncover major Nedd8-induced structural rearrangements of the CRL1 catalytic core. More importantly, we find that those changes are not induced by Nedd8(Q40E) conjugation, indicating that the subtle change of a single Nedd8 amino acid is sufficient to revert the structure of the CRL catalytic core back to its unmodified form. Our results provide new insights into how neddylation regulates the conformation and activity of CRLs. PMID:26632597

  10. Activation of adenosine A(3) receptors potentiates stimulatory effects of IL-3, SCF, and GM-CSF on mouse granulocyte-macrophage hematopoietic progenitor cells.

    PubMed

    Hofer, M; Vacek, A; Pospísil, M; Holá, J; Streitová, D; Znojil, V

    2009-01-01

    Adenosine A(3) receptor agonist N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA) has been tested from the point of view of potentiating the effects of hematopoietic growth factors interleukin-3 (IL-3), stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF) on the growth of hematopoietic progenitor cells for granulocytes and macrophages (GM-CFC) in suspension of normal mouse bone marrow cells in vitro. IB-MECA alone induced no GM-CFC growth. Significant elevation of numbers of GM-CFC evoked by the combinations of IB-MECA with IL-3, SCF, or GM-CSF as compared with these growth factors alone has been noted. Combination of IB-MECA with G-CSF did not induce significantly higher numbers of GM-CFC in comparison with G-CSF alone. Joint action of three drugs, namely of IB-MECA + IL-3 + GM-CSF, produced significantly higher numbers of GM-CFC in comparison with the combinations of IB-MECA + IL-3, IB-MECA + GM-CSF, or IL-3 + GM-CSF. These results give evidence of a significant role of selective activation of adenosine A(3) receptors in stimulation of the growth of granulocyte/ macrophage hematopoietic progenitor cells. PMID:18380545

  11. SCF ubiquitin ligase targeted therapies

    PubMed Central

    Skaar, Jeffrey R.; Pagan, Julia K.; Pagano, Michele

    2015-01-01

    Summary The recent clinical successes of inhibitors of the proteasome for the treatment of cancer have highlighted the therapeutic potential of this protein degradation system. Proteasome inhibitors prevent the degradation of numerous proteins, so increased specificity could be achieved by inhibiting the components of the ubiquitin-proteasome system that target specific subsets of proteins for degradation. F-box proteins are the substrate-targeting subunits of SKP1-CUL1-F-box protein (SCF) ubiquitin ligase complexes. Through the degradation of a plethora of diverse substrates, SCF ubiquitin ligases control a large number of processes at the cellular and organismal levels, and their misregulation is implicated in many pathologies. SCF ligases are characterized by a high specificity for their substrates, so they represent promising drug targets. However, the potential for therapeutic manipulation of SCF complexes remains an underdeveloped area. This review will explore and discuss potential strategies to target SCF-mediated biology to treat human diseases. PMID:25394868

  12. SCF, Regulated by HIF-1α, Promotes Pancreatic Ductal Adenocarcinoma Cell Progression

    PubMed Central

    Chen, Jing; Ren, He; Zhang, Huan; Wang, Xiuchao; Lang, Mingxiao; Liu, Jingcheng; Gao, Song; Zhao, Xiao; Sheng, Jun; Yuan, Zhanna; Hao, Jihui

    2015-01-01

    Stem cell factor (SCF) and hypoxia-inducible factor-1α (HIF-1α) both have important functions in pancreatic ductal adenocarcinoma (PDAC). This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP) assay, and luciferase assay analysis. The SCF level was also correlated with lymph node metastasis and the pathological tumor node metastasis (pTNM) stage in PDAC samples. The SCF higher-expression group had significantly lower survival rates than the SCF lower-expression group (p<0.05). Hypoxia up-regulated the expression of SCF through the hypoxia-inducible factor (HIF)-1α in PDAC cells at the protein and RNA levels. When HIF-1α was knocked down by RNA interference, the SCF level decreased significantly. Additionally, ChIP and luciferase results demonstrated that HIF-1α can directly bind to the hypoxia response element (HRE) region of the SCF promoter and activate the SCF transcription under hypoxia. The results of colony formation, cell scratch, and transwell migration assay showed that SCF promoted the proliferation and invasion of PANC-1 cells under hypoxia. Furthermore, the down-regulated ability of cell proliferation and invasion following HIF-1α knockdown was rescued by adding exogenous SCF under hypoxia in vitro. Finally, when the HIF-1α expression was inhibited by digoxin, the tumor volume and the SCF level decreased, thereby proving the relationship between HIF-1α and SCF in vivo. In conclusion, SCF is an important factor for the growth of PDAC. In our experiments, we proved that SCF, a downstream gene of HIF-1α, can promote the development of PDAC under hypoxia. Thus, SCF might be a potential therapeutic target for PDAC. PMID:25799412

  13. Gradient and mc scf calculations of the conformers and the formation of primary ethylene ozonide

    NASA Astrophysics Data System (ADS)

    Ruoff, Peter; Sæbø, Svein; Almlöf, Jan

    1981-11-01

    The confonners of primary ethylene ozonide have been studied by ab initio gradient and MC SCF calculations. At the MC SCF level they are more spread in energy than in SCF calculations. The planar conformer, carbon-carbon half chair and the oxygen envelope are much higher m energy than the other conformers. The MC SCF activation energy for cyclo-addition of ozone and ethylene is 91-99 kJ/mole.

  14. French space activities

    NASA Technical Reports Server (NTRS)

    Blanc, R.

    1982-01-01

    The four main points of research and development of space programs by France are explained. The National Center of Space Studies is discussed, listing the missions of the Center and describing the activities of the staff.

  15. Both SCF(Cdc4alpha) and SCF(Cdc4gamma) are required for cyclin E turnover in cell lines that do not overexpress cyclin E.

    PubMed

    Sangfelt, Olle; Cepeda, Diana; Malyukova, Alena; van Drogen, Frank; Reed, Steven I

    2008-04-15

    The ubiquitin-mediated turnover of cyclin E is regulated by phosphorylation and the activity of the ubiquitin ligase SCF(Cdc4) (also known as SCF(Fbw7)). In 293A cells, SCF complexes containing two different Cdc4 isoforms, alpha and gamma, are required for efficient cyclin E ubiquitylation. Whereas SCF(Cdc4gamma) ubiquitylates cyclin E directly, SCF(Cdc4alpha) serves as a cofactor for Pin1-mediated prolyl isomerization of the cyclin E phosphodegron, essential to potentiate ubiquitylation. In the current study, we show that the requirement for both Cdc4alpha and gamma is general, except in cell lines where cyclin E is expressed at an elevated level. Under these circumstances, Cdc4alpha is sufficient for cyclin E turnover. Furthermore, the requirement for Cdc4gamma can be bypassed by ectopic overexpression of cyclin E. PMID:18414042

  16. Space construction activities

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Center for Space Construction at the University of Colorado at Boulder was established in 1988 as a University Space Engineering Research Center. The mission of the Center is to conduct interdisciplinary engineering research which is critical to the construction of future space structures and systems and to educate students who will have the vision and technical skills to successfully lead future space construction activities. The research activities are currently organized around two central projects: Orbital Construction and Lunar Construction. Summaries of the research projects are included.

  17. Ongoing Space Nuclear Activities

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.

    2007-01-01

    Most ongoing US activities related to space nuclear power and propulsion are sponsored by NASA. NASA-spons0red space nuclear work is currently focused on evaluating potential fission surface power (FSP) systems and on radioisotope power systems (RPS). In addition, significant efforts related to nuclear thermal propulsion (NTP) systems have been completed and will provide a starting point for potential future NTP work.

  18. Activation of cellular immunity and marked inhibition of liver cancer in a mouse model following gene therapy and tumor expression of GM-SCF, IL-21, and Rae-1

    PubMed Central

    2013-01-01

    Background Cancer is both a systemic and a genetic disease. The pathogenesis of cancer might be related to dampened immunity. Host immunity recognizes nascent malignant cells – a process referred to as immune surveillance. Augmenting immune surveillance and suppressing immune escape are crucial in tumor immunotherapy. Methods A recombinant plasmid capable of co-expressing granulocyte-macrophage colony- stimulating factor (GM-SCF), interleukin-21 (IL-21), and retinoic acid early transcription factor-1 (Rae-1) was constructed, and its effects determined in a mouse model of subcutaneous liver cancer. Serum specimens were assayed for IL-2 and INF-γ by ELISA. Liver cancer specimens were isolated for Rae-1 expression by RT-PCR and Western blot, and splenocytes were analyzed by flow cytometry. Results The recombinant plasmid inhibited the growth of liver cancer and prolonged survival of tumor-loaded mice. Activation of host immunity might have contributed to this effect by promoting increased numbers and cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) following expression of GM-SCF, IL-21, and Rae-1. By contrast, the frequency of regulatory T cells was decreased, Consequently, activated CTL and NK cells enhanced their secretion of INF-γ, which promoted cytotoxicity of NK cells and CTL. Moreover, active CTL showed dramatic secretion of IL-2, which stimulates CTL. The recombinant expression plasmid also augmented Rae-1 expression by liver cancer cells. Rae-1 receptor expressing CTL and NK cells removed liver cancer. Conclusions The recombinant expression plasmid inhibited liver cancer by a mechanism that involved activation of cell-mediated immunity and Rae-1 in liver cancer. PMID:24350772

  19. Open Space Learning Activities

    ERIC Educational Resources Information Center

    Knapp, Clifford E.

    1976-01-01

    Describes a science activity in which students are given an opportunity to consider the values of open space. The program includes direct involvement as communicators of feelings and facts, leading students to a position of making wise decisions for land use in the future. (EB)

  20. Complete genome sequence of “Enterobacter lignolyticus” SCF1

    SciTech Connect

    DeAngelis, Kristen M.; D'Haeseleer, Patrik; Chivian, Dylan; Fortney, Julian L.; Khudyakov, Jane I.; Simmons, Blake A.; Woo, Hannah; Arkin, Adam P.; Davenport, Karen W.; Goodwin, Lynne A.; Chen, Amy; Ivanova, Natalia; Kyrpides, Nikos C.; Mavromatis, Konstantinos; Woyke, Tanja; Hazen, Terry C.

    2011-09-23

    In an effort to discover anaerobic bacteria capable of lignin degradation, we isolated 'Ente-robacter lignolyticus' SCF1 on minimal media with alkali lignin as the sole source of carbon. This organism was isolated anaerobically from tropical forest soils collected from the Short Cloud Forest site in the El Yunque National Forest in Puerto Rico, USA, part of the Luquillo Long-Term Ecological Research Station. At this site, the soils experience strong fluctuations in redox potential and are net methane producers. Because of its ability to grow on lignin anae-robically, we sequenced the genome. The genome of 'E. lignolyticus' SCF1 is 4.81 Mbp with no detected plasmids, and includes a relatively small arsenal of lignocellulolytic carbohy-drate active enzymes. Lignin degradation was observed in culture, and the genome revealed two putative laccases, a putative peroxidase, and a complete 4-hydroxyphenylacetate degra-dation pathway encoded in a single gene cluster.

  1. Space activities in Brazil

    NASA Astrophysics Data System (ADS)

    Carvalho, H.; Kono, J.; Quintino, M.; Perondi, L.

    Brazilian space activities develop around three main programs, namely, the China-Brazil Earth Resources Satellite (CBERS) , the Applications Satellite program, comprising the Multi-Mission Platform and associated remote sensing payloads (radar and optical), and the Scientific Satellites program. Increasing national industry participation and acquiring new technology are strategic goals established for all programs. CBERS program is the result of successful long term cooperation between China and Brazil for the development of remote sensing satellites. Initially comprising two satellites, launched in 1999 and 2003, and now extended to four, this cooperation fulfills the needs of both countries in earth imagery. CBERS satellites are designed for global coverage and include cameras for high spatial resolution and wide field of view, in the visible, near infrared spectrum, an infrared multi-spectral scanner, and a Transponder for the Brazilian Environmental Data Collection System to gather data on the environment. They are unique systems due to the use of onboard cameras which combine features that are specially designed to resolve the broad range of space and time scales involved in our ecosystem. Applications satellites, mainly devoted to optical and radar remote sensing, are being developed in the frame of international cooperation agreements, and will be based on the use of a recurrent Multi-Mission Platform (MMP), currently under development. The MMP will be 3-axes stabilized and will have a fine pointing capability, in several pointing modes, such as Earth, Inertial or Sun pointing. Missions will be focused on natural resources observation and monitoring.. The Program for Scientific Satellites is based on low-cost micro-satellites and aims at providing frequent flight opportunities for scientific research from space, whilst serving as a technological development platform, involving Research Institutes, Universities and National Industry. Current projects are FBM

  2. UHF natural orbitals for defining and starting MC-SCF calculations

    NASA Astrophysics Data System (ADS)

    Pulay, Peter; Hamilton, Tracy P.

    1988-04-01

    A simple way of generating starting orbitals for multiconfigurational SCF calculations (particularly of the CAS type) is to use the natural orbitals of the unrestricted Hartree-Fock wave function. Significant fractional occupancy of a UHF natural orbital indicates that the orbital should be included in the active space; this is illustrated for symmetrically stretched water, for NO, N2O4, and for the transition state on the Me3CO→Me2CO+CH3 reaction surface. Average natural orbitals should be used if there are several UHF solutions for the same state; this restores symmetry broken at the the UHF level. Configuration selection based on fractional occupation appears to be the basis for a reliable automated procedure. The UHF natural orbitals provide good starting orbitals for the two-configuration SCF and for the 4×4 CAS wave function in stretched F2, H2O2, and C2H6, methane, water, in twisted ethylene, in ozone, and for various CAS wave functions in the first asynchronous transition state of the HCNO+H2C2 1,3-cycloaddition. Comparison is made with the extended Hartree-Fock method.

  3. RIN3 is a negative regulator of mast cell responses to SCF.

    PubMed

    Janson, Christine; Kasahara, Noriyuki; Prendergast, George C; Colicelli, John

    2012-01-01

    Stimulation of the receptor tyrosine kinase KIT by Stem Cell Factor (SCF) triggers activation of RAS and its downstream effectors. Proper KIT activation is essential for the maturation, survival and proliferation of mast cells. In addition, SCF activation of KIT is critical for recruiting mast cells to sites of infection or injury, where they release a mix of pro-inflammatory substances. RIN3, a RAS effector and RAB5-directed guanine nucleotide exchange factor (GEF), is highly expressed and enriched in human mast cells. SCF treatment of mast cells increased the amount of GTP-bound RAB5, and the degree of RAB5 activation correlated with the expression level of RIN3. At the same time, SCF caused the dissociation of a pre-formed complex of RIN3 with BIN2, a membrane bending protein implicated in endocytosis. Silencing of RIN3 increased the rate of SCF-induced KIT internalization, while persistent RIN3 over-expression led to KIT down regulation. These observations strongly support a role for RIN3 in coordinating the early steps of KIT endocytosis. Importantly, RIN3 also functioned as an inhibitor of mast cell migration toward SCF. Finally, we demonstrate that elevated RIN3 levels sensitize mastocytosis cells to treatment with a KIT tyrosine kinase inhibitor, suggesting the value of a two-pronged inhibitor approach for this difficult to treat malignancy. These findings directly connect KIT activation with a mast cell-specific RAS effector that regulates the cellular response to SCF and provide new insight for the development of more effective mastocytosis treatments. PMID:23185384

  4. Canadian space robotic activities

    NASA Astrophysics Data System (ADS)

    Sallaberger, Christian; Space Plan Task Force, Canadian Space Agency

    The Canadian Space Agency has chosen space robotics as one of its key niche areas, and is currently preparing to deliver the first flight elements for the main robotic system of the international space station. The Mobile Servicing System (MSS) is the Canadian contribution to the international space station. It consists of three main elements. The Space Station Remote Manipulator System (SSRMS) is a 7-metre, 7-dof, robotic arm. The Special Purpose Dextrous Manipulator (SPDM), a smaller 2-metre, 7-dof, robotic arm can be used independently, or attached to the end of the SSRMS. The Mobile Base System (MBS) will be used as a support platform and will also provide power and data links for both the SSRMS and the SPDM. A Space Vision System (SVS) has been tested on Shuttle flights, and is being further developed to enhance the autonomous capabilities of the MSS. The CSA also has a Strategic Technologies in Automation and Robotics Program which is developing new technologies to fulfill future robotic space mission needs. This program is currently developing in industry technological capabilities in the areas of automation of operations, autonomous robotics, vision systems, trajectory planning and object avoidance, tactile and proximity sensors, and ground control of space robots. Within the CSA, a robotic testbed and several research programs are also advancing technologies such as haptic devices, control via head-mounted displays, predictive and preview displays, and the dynamic characterization of robotic arms. Canada is also now developing its next Long Term Space Plan. In this context, a planetary exploration program is being considered, which would utilize Canadian space robotic technologies in this new arena.

  5. Antibiotic activity in space.

    PubMed

    Lapchine, L; Moatti, N; Gasset, G; Richoilley, G; Templier, J; Tixador, R

    1986-01-01

    Environmental factors in space exert an influence on the behaviour of bacteria, particularly on their sensitivity to antibiotics. Thus, G. Taylor and S. Zaloguev observed that bacterial samples collected on the crew during flight in the Apollo-Soyouz Test Project Mission presented higher antibiotic resistance than controls. This paper presents the results of two experiments performed in 1982 and 1985 (Cytos 2 during the French-Soviet Mission and "Antibio" in the Biorack programme of the European Space Agency). The results show an increase of antibiotic resistance in bacteria growth in flight and a modification in the structure of the cell wall. All these modifications are transitory. Two hypotheses are put forward to explain the phenomenon. PMID:3569006

  6. Suprafacial Orientation of the SCF[superscript Cdc4] Dimer Accommodates Multiple Geometries for Substrate Ubiquitination

    SciTech Connect

    Tang, Xiaojing; Orlicky, Stephen; Lin, Zhenyuan; Willems, Andrew; Neculai, Dante; Ceccarelli, Derek; Mercurio, Frank; Shilton, Brian H.; Sicheri, Frank; Tyers, Mike

    2008-07-15

    SCF ubiquitin ligases recruit substrates for degradation via F box protein adaptor subunits. WD40 repeat F box proteins, such as Cdc4 and {beta}-TrCP, contain a conserved dimerization motif called the D domain. Here, we report that the D domain protomers of yeast Cdc4 and human {beta}-TrCP form a superhelical homotypic dimer. Disruption of the D domain compromises the activity of yeast SCF{sup Cdc4} toward the CDK inhibitor Sic1 and other substrates. SCF{sup Cdc4} dimerization has little effect on the affinity for Sic1 but markedly stimulates ubiquitin conjugation. A model of the dimeric holo-SCF{sup Cdc4} complex based on small-angle X-ray scatter measurements reveals a suprafacial configuration, in which substrate-binding sites and E2 catalytic sites lie in the same plane with a separation of 64 {angstrom} within and 102 {angstrom} between each SCF monomer. This spatial variability may accommodate diverse acceptor lysine geometries in both substrates and the elongating ubiquitin chain and thereby increase catalytic efficiency.

  7. Thermal Expansion of ScF3

    NASA Astrophysics Data System (ADS)

    Bhandia, R.; Grockowiak, A.; Siegrist, T.; Besara, T.; Tozer, S. W.; Schmiedeshoff, G. M.

    ScF3 is an insulator, has a cubic crystal structure, and exhibits negative thermal expansion over a very wide temperature range. We will present and discuss thermal expansion measurements made with capacitive and fiber-Bragg-grating dilatometers. Work at Occidental College is supported by the National Science Foundation under DMR- 1408598. A portion of this work was funded by the US Department of Energy NNSA SSAA DE-NA0001979, and performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1157490 and the State of Florida.

  8. Space weather activities in Australia

    NASA Astrophysics Data System (ADS)

    Cole, D.

    Space Weather Plan Australia has a draft space weather plan to drive and focus appropriate research into services that meet future industry and social needs. The Plan has three main platforms, space weather monitoring and service delivery, support for priority research, and outreach to the community. The details of monitoring, service, research and outreach activities are summarised. A ground-based network of 14 monitoring stations from Antarctica to Papua New Guinea is operated by IPS, a government agency. These sites monitor ionospheric and geomagnetic characteristics, while two of them also monitor the sun at radio and optical wavelengths. Services provided through the Australian Space Forecast Centre (ASFC) include real-time information on the solar, space, ionospheric and geomagnetic environments. Data are gathered automatically from monitoring sites and integrated with data exchanged internationally to create snapshots of current space weather conditions and forecasts of conditions up to several days ahead. IPS also hosts the WDC for Solar-Terrestrial Science and specialises in ground-based solar, ionospheric, and geomagnetic data sets, although recent in-situ magnetospheric measurements are also included. Space weather activities A research consortium operates the Tasman International Geospace Environment Radar (TIGER), an HF southward pointing auroral radar operating from Hobart (Tasmania). A second cooperative radar (Unwin radar) is being constructed in the South Island of New Zealand. This will intersect with TIGER over the auroral zone and enhance the ability of the radar to image the surge of currents that herald space environment changes entering the Polar Regions. Launched in November 2002, the micro satellite FEDSAT, operated by the Cooperative Research Centre for Satellite Systems, has led to successful space science programs and data streams. FEDSAT is making measurements of the magnetic field over Australia and higher latitudes. It also carries a

  9. SCF(Fbxo22)-KDM4A targets methylated p53 for degradation and regulates senescence.

    PubMed

    Johmura, Yoshikazu; Sun, Jia; Kitagawa, Kyoko; Nakanishi, Keiko; Kuno, Toshiya; Naiki-Ito, Aya; Sawada, Yumi; Miyamoto, Tomomi; Okabe, Atsushi; Aburatani, Hiroyuki; Li, ShengFan; Miyoshi, Ichiro; Takahashi, Satoru; Kitagawa, Masatoshi; Nakanishi, Makoto

    2016-01-01

    Recent evidence has revealed that senescence induction requires fine-tuned activation of p53, however, mechanisms underlying the regulation of p53 activity during senescence have not as yet been clearly established. We demonstrate here that SCF(Fbxo22)-KDM4A is a senescence-associated E3 ligase targeting methylated p53 for degradation. We find that Fbxo22 is highly expressed in senescent cells in a p53-dependent manner, and that SCF(Fbxo22) ubiquitylated p53 and formed a complex with a lysine demethylase, KDM4A. Ectopic expression of a catalytic mutant of KDM4A stabilizes p53 and enhances p53 interaction with PHF20 in the presence of Fbxo22. SCF(Fbxo22)-KDM4A is required for the induction of p16 and senescence-associated secretory phenotypes during the late phase of senescence. Fbxo22(-/-) mice are almost half the size of Fbxo22(+/-) mice owing to the accumulation of p53. These results indicate that SCF(Fbxo22)-KDM4A is an E3 ubiquitin ligase that targets methylated p53 and regulates key senescent processes. PMID:26868148

  10. Space Station Freedom propulsion activities

    NASA Technical Reports Server (NTRS)

    Spera, David A. (Editor)

    1990-01-01

    The technical highlights and accomplishments made at NASA LeRC in the development of the Space Station Freedom (SSF) propulsion system are discussed. The objectives are as follows: develop and characterize resistojet-thruster components and assemblies; develop and characterize hydrogen-oxygen thruster components; and conduct system trade studies. The research projects primarily characterize propulsion performance and life. Other tests include environmental impacts, such as exhaust gas profiles and electromagnetic interference. The technical activities that are highlighted are being conducted at LeRC within the Aerospace Technology and Space Station Freedom directorates. These activities include the following: derivation of design analysis models; trade studies of design options; propulsion system impact studies; and component testing for characterization and design verification.

  11. MondoSCF V1.0 Alpha 10

    2004-11-29

    MondoSCF is an experimental code for Quantum Chemistry. Quantum Chemistry involves approximate solutions to the Schrodinger equation for the prediction of chemical properties and their theoretical interpretation. The main thrust of MondoSCF is the development of leading edge, reduced complexity algorithms that scale linearly with system size. MondoSCF is highly modular, and has been written in object oriented Fortran9O. Fortran77, C and Mathematica. Platform independent 10 is supported with HDF5. MondoSCF has incorporated several externalmore » contributions. These include PhiPAC for optimized matrix-matrix multiplies, several Mathematica packages for producing source code from algebraic equations, and various routines from the SLATEC library. Platforms on which MondoSCF is known to run include IRIX/MIPSF9O, LINUXIPGF9O, LINUXINAGF95, TRUE64IF95 and AIXJXLF9O. Currently, MondoSCF performs Hartree-Fock, pure Density Functional, and hybrid HF/DFT calculations in a Cartesian-Gaussian basis. All algorithms are linear scaling. The code applies to both gas phase and periodic systems, and is capable of geometry optimization and molecular dynamics. The code enjoys limited parallelism, and is capable of linear scaling response theory.« less

  12. MondoSCF V1.0 Alpha 10

    SciTech Connect

    Challacombe, Matt

    2004-11-29

    MondoSCF is an experimental code for Quantum Chemistry. Quantum Chemistry involves approximate solutions to the Schrodinger equation for the prediction of chemical properties and their theoretical interpretation. The main thrust of MondoSCF is the development of leading edge, reduced complexity algorithms that scale linearly with system size. MondoSCF is highly modular, and has been written in object oriented Fortran9O. Fortran77, C and Mathematica. Platform independent 10 is supported with HDF5. MondoSCF has incorporated several external contributions. These include PhiPAC for optimized matrix-matrix multiplies, several Mathematica packages for producing source code from algebraic equations, and various routines from the SLATEC library. Platforms on which MondoSCF is known to run include IRIX/MIPSF9O, LINUXIPGF9O, LINUXINAGF95, TRUE64IF95 and AIXJXLF9O. Currently, MondoSCF performs Hartree-Fock, pure Density Functional, and hybrid HF/DFT calculations in a Cartesian-Gaussian basis. All algorithms are linear scaling. The code applies to both gas phase and periodic systems, and is capable of geometry optimization and molecular dynamics. The code enjoys limited parallelism, and is capable of linear scaling response theory.

  13. Ubiquitylation of cyclin E requires the sequential function of SCF complexes containing distinct hCdc4 isoforms.

    PubMed

    van Drogen, Frank; Sangfelt, Olle; Malyukova, Aljona; Matskova, Ludmila; Yeh, Elizabeth; Means, Anthony R; Reed, Steven I

    2006-07-01

    Cyclin E, an activator of cyclin-dependent kinase 2 (Cdk2), is targeted for proteasomal degradation by phosphorylation-dependent multiubiquitylation via the ubiquitin ligase SCF(hCdc4). SCF ubiquitin ligases are composed of a core of conserved subunits and one variable subunit (an F box protein) involved in substrate recognition. We show here that multiubiquitylation of cyclin E requires the sequential function of two distinct splice variant isoforms of the F box protein hCdc4 known as alpha and gamma. SCF(hCdc4alpha) binds a complex containing cyclin E, Cdk2, and the prolyl cis/trans isomerase Pin1 and promotes the activity of Pin1 without directly ubiquitylating cyclin E. However, due to the action of this SCF(hCdc4alpha)-Pin1 complex, cyclin E becomes an efficient ubiquitylation substrate of SCF(hCdc4gamma). Furthermore, in the context of Cdc4alpha and cyclin E, mutational data suggest that Pin1 isomerizes a noncanonical proline-proline bond, with the possibility that Cdc4alpha may serve as a cofactor for altering the specificity of Pin1. PMID:16818231

  14. Characterization of SCF-Complex during Bovine Preimplantation Development

    PubMed Central

    Benesova, Veronika; Kinterova, Veronika; Kanka, Jiri; Toralova, Tereza

    2016-01-01

    The degradation of maternal proteins is one of the most important events during early development, and it is presumed to be essential for embryonic genome activation (EGA), but the precise mechanism is still not known. It is thought that a large proportion of the degradation of maternal proteins is mediated by the ubiquitin-proteolytic system. In this study we focused on the expression of the Skp1-Cullin1-F-box (SCF) complex, a modular RING-type E3 ubiquitin-ligase, during bovine preimplantation development. The complex consists of three invariable components—Cul1, Skp1, Rbx1 and F-box protein, which determines the substrate specificity. The protein level and mRNA expression of all three invariable members were determined. Cul1 and Skp1 mRNA synthesis was activated at early embryonic stages, at the 4c and early 8c stage, respectively, which suggests that these transcripts are necessary for preparing the embryo for EGA. CUL1 protein level increased from MII to the morula stage, with a significant difference between MII and L8c, and between MII and the morula. The CUL1 protein was localized primarily to nuclei and to a lesser extent to the cytoplasm, with a lower signal in the inner cell mass (ICM) compared to the trophectoderm (TE) at the blastocyst stage. The level of SKP1 protein significantly increased from MII oocytes to 4c embryos, but then significantly decreased again. The localization of the SKP1 protein was analysed throughout the cell and similarly to CUL1 at the blastocyst stage, the staining was less intensive in the ICM. There were no statistical differences in RBX1 protein level and localization. The active SCF-complex, which is determined by the interaction of Cul1 and Skp1, was found throughout the whole embryo during preimplantation development, but there was a difference at the blastocyst stage, which exhibits a much stronger signal in the TE than in the ICM. These results suggest that all these genes could play an important role during

  15. Interpretation of unexpected behavior of infrared absorption spectra of ScF3 beyond the quasiharmonic approximation

    NASA Astrophysics Data System (ADS)

    Piskunov, Sergei; Žguns, Pjotrs A.; Bocharov, Dmitry; Kuzmin, Alexei; Purans, Juris; Kalinko, Aleksandr; Evarestov, Robert A.; Ali, Shehab E.; Rocca, Francesco

    2016-06-01

    Scandium fluoride (ScF3), having cubic ReO3-type structure, has attracted much scientific attention due to its rather strong negative thermal expansion (NTE) in the broad temperature range from 10 to 1100 K. Here we use the results of diffraction and extended x-ray absorption fine-structure (EXAFS) spectroscopy to interpret the influence of NTE on the temperature dependence of infrared absorption spectra of ScF3. Original infrared absorption and EXAFS experiments in a large temperature range are presented and interpreted using ab initio lattice dynamics simulations within and beyond quasiharmonic approximations. We demonstrate that ab initio electronic structure calculations, based on the linear combination of atomic orbitals method with hybrid functionals, are able to reproduce well the experimental values of lattice parameter a0, band gap Eg, and lattice dynamics in ScF3. However, the simulations performed within quasiharmonic approximation fail to reproduce the temperature dependence of two infrared active bands due to the F-Sc-F bending (at 220 cm-1) and Sc-F stretching (at 520 cm-1) modes present in the infrared absorption spectra. To overcome this problem, an approach beyond the quasiharmonic approximation is proposed: It accounts for the negative thermal expansion of the lattice and for fluorine atom displacements due to strong F vibrational motion perpendicular to the cubic axes and allows us to explain qualitatively the temperature behavior of infrared spectra of ScF3.

  16. Trends in space activities in 2014: The significance of the space activities of governments

    NASA Astrophysics Data System (ADS)

    Paikowsky, Deganit; Baram, Gil; Ben-Israel, Isaac

    2016-01-01

    This article addresses the principal events of 2014 in the field of space activities, and extrapolates from them the primary trends that can be identified in governmental space activities. In 2014, global space activities centered on two vectors. The first was geopolitical, and the second relates to the matrix between increasing commercial space activities and traditional governmental space activities. In light of these two vectors, the article outlines and analyzes trends of space exploration, human spaceflights, industry and technology, cooperation versus self-reliance, and space security and sustainability. It also reviews the space activities of the leading space-faring nations.

  17. The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.

    PubMed

    Wang, Xiping; Feng, Suhua; Nakayama, Naomi; Crosby, W L; Irish, Vivian; Deng, Xing Wang; Wei, Ning

    2003-05-01

    The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation. PMID:12724534

  18. The SCF/c-KIT system in the male: Survival strategies in fertility and cancer.

    PubMed

    Cardoso, Henrique J; Figueira, Marília I; Correia, Sara; Vaz, Cátia V; Socorro, Sílvia

    2014-12-01

    Maintaining the delicate balance between cell survival and death is of the utmost importance for the proper development of germ cells and subsequent fertility. On the other hand, the fine regulation of tissue homeostasis by mechanisms that control cell fate is a factor that can prevent carcinogenesis. c-KIT is a type III receptor tyrosine kinase activated by its ligand, stem cell factor (SCF). c-KIT signaling plays a crucial role in cell fate decisions, specifically controlling cell proliferation, differentiation, survival, and apoptosis. Indeed, deregulating the SCF/c-KIT system by attenuation or overactivation of its signaling strength is linked to male infertility and cancer, and rebalancing its activity via c-KIT inhibitors has proven beneficial in treating human tumors that contain gain-of-function mutations or overexpress c-KIT. This review addresses the roles of SCF and c-KIT in the male reproductive tract, and discusses the potential application of c-KIT target therapies in disorders of the reproductive system. PMID:25359157

  19. Localized SCF and IGF-1 secretion enhances erythropoiesis in the spleen of murine embryos

    PubMed Central

    Tan, Keai Sinn; Inoue, Tomoko; Kulkeaw, Kasem; Tanaka, Yuka; Lai, Mei I; Sugiyama, Daisuke

    2015-01-01

    Fetal spleen is a major hematopoietic site prior to initiation of bone marrow hematopoiesis. Morphologic analysis suggested erythropoietic activity in fetal spleen, but it remained unclear how erythropoiesis was regulated. To address this question, we performed flow cytometric analysis and observed that the number of spleen erythroid cells increased 18.6-fold from 16.5 to 19.5 days post-coitum (dpc). Among erythropoietic cytokines, SCF and IGF-1 were primarily expressed in hematopoietic, endothelial and mesenchymal-like fetal spleen cells. Cultures treated with SCF and/or IGF-1R inhibitors showed significantly decreased CD45−c-Kit−CD71+/−Ter119+ erythroid cells and downregulated Gata1, Klf1 and β-major globin expression. Administration of these inhibitors to pregnant mice significantly decreased the number of CD45−c-Kit−CD71+/−Ter119+ cells and downregulated β-major globin gene expression in embryos derived from these mice. We conclude that fetal spleen is a major erythropoietic site where endothelial and mesenchymal-like cells primarily accelerate erythropoietic activity through SCF and IGF-1 secretion. PMID:25887124

  20. Space Research, Education, and Related Activities in the Space Sciences

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Universities Space Research Association received an award of Cooperative Agreement #NCC5-356 on September 29, 1998. The mission of this activity, know as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, USRA recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members.

  1. Space Research, Education, and Related Activities In the Space Sciences

    NASA Technical Reports Server (NTRS)

    Black, David

    2002-01-01

    The mission of this activity, known as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, the Universities Space Research Association (USRA) recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members. This paper is the final report from this now completed Cooperative Agreement.

  2. Space Research, Education, and Related Activities in the Space Sciences

    NASA Technical Reports Server (NTRS)

    Black, David; Marshall, Frank (Technical Monitor)

    2002-01-01

    The Universities Space Research Association received an award of Cooperative Agreement NCC5-356 on September 29, 1998. The mission of this activity, known as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, USRA recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members.

  3. Differential regulation of gene expression in mouse spermatogonial cells after blocking c-kit-SCF interaction with RNAi

    PubMed Central

    Sikarwar, Arun P; Rambabu, Murali K; Reddy, K V R

    2008-01-01

    c-Kit, the gene product of the W locus is a receptor tyrosine kinase that regulates the survival, growth and differentiation of spermatogonial cells (SGCs). Stem cell factor (SCF), the gene product of the steel (Sl) locus is the ligand for c-kit. Normal function of SGCs requires cross-talk between c-kit and SCF through which the receptor-ligand pair regulates the functions of SGCs. The implications of cross-talk between c-kit and SCF in regulating SGC function remains unclear due to the molecular complexity of this interaction. In the present study, we analyzed the interactions between c-kit and SCF in mouse primary SGCs after blocking the c-kit expression by c-kit siRNA and its effect on cell fate were determined using cDNA Expression Array and Real-time PCR. Immunofluorescence (IF) and western blot studies revealed that c-kit protein was detected in SGCs and knocked down to undetectable levels at 24 hr post transfection with 10 nM concentration of c-kit siRNA. We further demonstrated that expression of various genes involved in cell signaling, cell differentiation, apoptosis and cell cycle pathways was altered. SGC functions are affected by SCF signaling through c-kit receptor and this signaling appears to be important to maintain balance between cell proliferation and apoptosis along with the modulation of inflammatory responses of SGCs. To the best of our knowledge, this is the first report that identifies the putative molecular pathways in murine SGCs in response to specific blocking of c-kit-SCF interactions by siRNA. In conclusion, the present study may provide useful insights into siRNA function and hopefully aid in understanding the involvement of c-kit in the early events of SGC activities and spermatogenesis in mice. PMID:19771240

  4. Space activities and global popular music culture

    NASA Astrophysics Data System (ADS)

    Wessels, Allison Rae; Collins, Patrick

    During the "space age" era, space activities appear increasingly as a theme in Western popular music, as they do in popular culture generally. In combination with the electronics and tele-communications revolution, "pop/rock" music has grown explosively during the space age to become an effectively global culture. From this base a number of trends are emerging in the pattern of influences that space activities have on pop music. The paper looks at the use of themes and imagery in pop music; the role of space technology in the modern "globalization" of pop music; and current and future links between space activities and pop music culture, including how public space programmes are affected by its influence on popular attitudes.

  5. History and Evolution of Active Learning Spaces

    ERIC Educational Resources Information Center

    Beichner, Robert J.

    2014-01-01

    This chapter examines active learning spaces as they have developed over the years. Consistently well-designed classrooms can facilitate active learning even though the details of implementing pedagogies may differ.

  6. Regulation of flower development in Arabidopsis by SCF complexes.

    PubMed

    Ni, Weimin; Xie, Daoxin; Hobbie, Lawrence; Feng, Baomin; Zhao, Dazhong; Akkara, Joseph; Ma, Hong

    2004-04-01

    SCF complexes are the largest and best studied family of E3 ubiquitin protein ligases that facilitate the ubiquitylation of proteins targeted for degradation. The SCF core components Skp1, Cul1, and Rbx1 serve in multiple SCF complexes involving different substrate-specific F-box proteins that are involved in diverse processes including cell cycle and development. In Arabidopsis, mutations in the F-box gene UNUSUAL FLORAL ORGANS (UFO) result in a number of defects in flower development. However, functions of the core components Cul1 and Rbx1 in flower development are poorly understood. In this study we analyzed floral phenotypes caused by altering function of Cul1 or Rbx1, as well as the effects of mutations in ASK1 and ASK2. Plants homozygous for a point mutation in the AtCUL1 gene showed reduced floral organ number and several defects in each of the four whorls. Similarly, plants with reduced AtRbx1 expression due to RNA interference also exhibited floral morphological defects. In addition, compared to the ask1 mutant, plants homozygous for ask1 and heterozygous for ask2 displayed enhanced reduction of B function, as well as other novel defects of flower development, including carpelloid sepals and an inhibition of petal development. Genetic analyses demonstrate that AGAMOUS (AG) is required for the novel phenotypes observed in the first and second whorls. Furthermore, the genetic interaction between UFO and AtCUL1 supports the idea that UFO regulates multiple aspects of flower development as a part of SCF complexes. These results suggest that SCF complexes regulate several aspects of floral development in Arabidopsis. PMID:15047903

  7. Stennis hosts Space Day activities at USM

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Fallon Nettles (left), an Astro Camp counselor at NASA's John C. Stennis Space Center, assists a young fan attending the University of Southern Mississippi football game in Hattiesburg, Miss., on Oct. 17 in launching a balloon 'rocket.' Prior to the game, Stennis Space Center hosted hands-on activities and exhibits for families as part of its first-ever Space Day at USM. The activities were versions of those featured in the daylong and weeklong Astro Camp sessions sponsored by Stennis throughout each year. Stennis Space Center is located in nearby Hancock County and is the nation's premier rocket engine testing facility. The USM activities were part of Stennis' ongoing effort to educate people about the NASA mission and to introduce children and young people to space and space exploration.

  8. Space activities in 2009/2010

    NASA Astrophysics Data System (ADS)

    Pagkratis, Spyros

    2011-09-01

    The global financial crisis of 2008 has created an economic environment unfavourable to public and corporate economic activity alike, which could not have left space activities unaffected. However, the effects of the crisis upon the space sector have been so far less damaging than anticipated. The following paper presents recent developments in the field of space policies, institutional budgets and commercial activity worldwide, in an effort to improve the understanding of the new trends in commercial and public space activities. It particularly explores the strategies followed by space stakeholders in different countries and regions in order to pursue their planned space programmes in view of difficult financial conditions. Finally, it highlights the differences in the outlook of space activities between established and emerging space-faring nations and attempts to explore their medium-term consequences on an international level. For this purpose, it was based on research conducted in the framework of a recent ESPI report on "Space Policies, Issues and trends in 2009/2010".

  9. Aeronautics and space report of the President: 1981 activities

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Achievements in the aeronautics and space program by function are summarized. Activities in communications, Earth's resources and environment, space science, space transportation, international activities, and aeronautics are included.

  10. Operational Space Weather Activities in the US

    NASA Astrophysics Data System (ADS)

    Berger, Thomas; Singer, Howard; Onsager, Terrance; Viereck, Rodney; Murtagh, William; Rutledge, Robert

    2016-07-01

    We review the current activities in the civil operational space weather forecasting enterprise of the United States. The NOAA/Space Weather Prediction Center is the nation's official source of space weather watches, warnings, and alerts, working with partners in the Air Force as well as international operational forecast services to provide predictions, data, and products on a large variety of space weather phenomena and impacts. In October 2015, the White House Office of Science and Technology Policy released the National Space Weather Strategy (NSWS) and associated Space Weather Action Plan (SWAP) that define how the nation will better forecast, mitigate, and respond to an extreme space weather event. The SWAP defines actions involving multiple federal agencies and mandates coordination and collaboration with academia, the private sector, and international bodies to, among other things, develop and sustain an operational space weather observing system; develop and deploy new models of space weather impacts to critical infrastructure systems; define new mechanisms for the transition of research models to operations and to ensure that the research community is supported for, and has access to, operational model upgrade paths; and to enhance fundamental understanding of space weather through support of research models and observations. The SWAP will guide significant aspects of space weather operational and research activities for the next decade, with opportunities to revisit the strategy in the coming years through the auspices of the National Science and Technology Council.

  11. Landsat: Space Activities for Students

    ERIC Educational Resources Information Center

    Marks, Steven K.

    1979-01-01

    An aerospace education activity is described which is suitable for grades 3-12. Students piece together several images from the Landsat satellite to make a mosaic of their state. From the mosaic clear acetate overlay maps can be made relating to such subjects as agriculture, geology, hydrology, or urban planning. (BB)

  12. Active Control of Cryogenic Propellants in Space

    NASA Technical Reports Server (NTRS)

    Notardonato, William

    2011-01-01

    A new era of space exploration is being planned. Exploration architectures under consideration require the long term storage of cryogenic propellants in space. This requires development of active control systems to mitigate the effect of heat leak. This work summarizes current state of the art, proposes operational design strategies and presents options for future architectures. Scaling and integration of active systems will be estimated. Ideal long range spacecraft systems will be proposed with Exploration architecture benefits considered.

  13. Measuring segregation: an activity space approach

    PubMed Central

    Shaw, Shih-Lung

    2010-01-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual’s segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial–ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces. PMID:21643546

  14. Measuring segregation: an activity space approach

    NASA Astrophysics Data System (ADS)

    Wong, David W. S.; Shaw, Shih-Lung

    2011-06-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual's segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial-ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces.

  15. Space station freedom life sciences activities

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.

    1994-01-01

    Life sciences activities being planned for Space Station Freedom (SSF) as of Fall 1992 are discussed. Planning for these activities is ongoing. Therefore, this description should be viewed as indicative of the prevailing ideas at one particular time in the SSF development cycle. The proposed contributions of the Canadian Space Agency (CSN) the European Space Agency (ESA), Japan, and the United States are all discussed in detail. In each case, the life sciences goals, and the way in which each partner proposes to achieve their goals, are reviewed.

  16. Canadian Activities in Space Debris Mitigation Technologies

    NASA Astrophysics Data System (ADS)

    Nikanpour, Darius; Jiang, Xin Xiang; Goroshin, Samuel; Haddad, Emile; Kruzelecky, Roman; Hoa, Suong; Merle, Philippe; Kleiman, Jacob; Gendron, Stephane; Higgins, Andrew; Jamroz, Wes

    The space environment, and in particular the Low Earth Orbit (LEO), is becoming increasingly populated with space debris which include fragments of dysfunctional spacecraft parts and materials traveling at speeds up to 15 km per second. These pose an escalating potential threat to LEO spacecraft, the international space station, and manned missions. This paper presents the Canadian activities to address the concerns over space debris in terms of debris mitigation measures and technologies; these include novel spacecraft demise technologies to safely decommission the spacecraft at the end of the mission, integrated self-healing material technologies for spacecraft structures to facilitate self-repair and help maintain the spacecraft structural and thermal performance, hypervelocity ground test capability to predict the impact of space debris on spacecraft performance, and ways of raising awareness within the space community through participation in targeted Science and Technology conferences and international forums.

  17. Space Activities for the Visually Impaired

    NASA Astrophysics Data System (ADS)

    Ries, J. G.; Baguio, M.

    2005-12-01

    To a visually impaired person celestial objects or concepts of space exploration are likely to be more abstract than to other people, but they encounter news about the universe through their daily life. A partnership between Texas Space Grant Consortium, The University of Texas at Austin, and the Texas School for the Blind and Visually Impaired provided the opportunity to assist visually impaired students increase their understanding of astronomy and space science. The activities helped visually impaired students activity engage in inquiry-based, hands-on astronomy activities. The experiences provided during the educator workshops, adapted instructional classroom activities, and tactile learning aids will be shared in the hopes that others may be able to incorporate these lessons into their regular teaching activities.

  18. A general parallel sparse-blocked matrix multiply for linear scaling SCF theory

    NASA Astrophysics Data System (ADS)

    Challacombe, Matt

    2000-06-01

    A general approach to the parallel sparse-blocked matrix-matrix multiply is developed in the context of linear scaling self-consistent-field (SCF) theory. The data-parallel message passing method uses non-blocking communication to overlap computation and communication. The space filling curve heuristic is used to achieve data locality for sparse matrix elements that decay with “separation”. Load balance is achieved by solving the bin packing problem for blocks with variable size.With this new method as the kernel, parallel performance of the simplified density matrix minimization (SDMM) for solution of the SCF equations is investigated for RHF/6-31G ∗∗ water clusters and RHF/3-21G estane globules. Sustained rates above 5.7 GFLOPS for the SDMM have been achieved for (H 2 O) 200 with 95 Origin 2000 processors. Scalability is found to be limited by load imbalance, which increases with decreasing granularity, due primarily to the inhomogeneous distribution of variable block sizes.

  19. SCF/c-kit transactivates CXCR4-serine 339 phosphorylation through G protein-coupled receptor kinase 6 and regulates cardiac stem cell migration.

    PubMed

    Zuo, Ke; Kuang, Dong; Wang, Ying; Xia, Yanli; Tong, Weilin; Wang, Xiaoyan; Chen, Yaobin; Duan, Yaqi; Wang, Guoping

    2016-01-01

    C-kit positive cardiac stem cells (CSCs) have been shown to contribute to myocardial regeneration after infarction. Previously, we have shown that the c-kit ligand stem cell factor (SCF) can induce CSC migration into the infarcted area during myocardial infarction (MI). However, the precise mechanism involved is not fully understood. In this study, we found that CSCs also express C-X-C chemokine receptor type 4 (CXCR4), which is a typical member of the seven transmembrane-spanning G protein-coupled receptor (GPCR). In vitro, activation of c-kit signalling by SCF promotes migration of CSCs with increased phosphorylation of CXCR4-serine 339, p38 mitogen-activated protein kinase (p38 MAPK) and extracellular regulated protein kinases 1/2 (ERK1/2). Knockdown of CXCR4 expression by siRNA reduces SCF/c-kit-induced migration and downstream signalling. As previously reported, CXCR4-serine 339 phosphorylation is mainly regulated by GPCR kinase 6 (GRK6); thus, silencing of GRK6 expression by siRNA impairs CXCR4-serine 339 phosphorylation and migration of CSCs caused by SCF. In vivo, knockdown of GRK6 impairs the ability of CSCs to migrate into peri-infarcted areas. These results demonstrate that SCF-induced CSC migration is regulated by the transactivation of CXCR4-serine 339 phosphorylation, which is mediated by GRK6. PMID:27245949

  20. SCF/c-kit transactivates CXCR4-serine 339 phosphorylation through G protein-coupled receptor kinase 6 and regulates cardiac stem cell migration

    PubMed Central

    Zuo, Ke; Kuang, Dong; Wang, Ying; Xia, Yanli; Tong, Weilin; Wang, Xiaoyan; Chen, Yaobin; Duan, Yaqi; Wang, Guoping

    2016-01-01

    C-kit positive cardiac stem cells (CSCs) have been shown to contribute to myocardial regeneration after infarction. Previously, we have shown that the c-kit ligand stem cell factor (SCF) can induce CSC migration into the infarcted area during myocardial infarction (MI). However, the precise mechanism involved is not fully understood. In this study, we found that CSCs also express C-X-C chemokine receptor type 4 (CXCR4), which is a typical member of the seven transmembrane-spanning G protein-coupled receptor (GPCR). In vitro, activation of c-kit signalling by SCF promotes migration of CSCs with increased phosphorylation of CXCR4-serine 339, p38 mitogen-activated protein kinase (p38 MAPK) and extracellular regulated protein kinases 1/2 (ERK1/2). Knockdown of CXCR4 expression by siRNA reduces SCF/c-kit-induced migration and downstream signalling. As previously reported, CXCR4-serine 339 phosphorylation is mainly regulated by GPCR kinase 6 (GRK6); thus, silencing of GRK6 expression by siRNA impairs CXCR4-serine 339 phosphorylation and migration of CSCs caused by SCF. In vivo, knockdown of GRK6 impairs the ability of CSCs to migrate into peri-infarcted areas. These results demonstrate that SCF-induced CSC migration is regulated by the transactivation of CXCR4-serine 339 phosphorylation, which is mediated by GRK6. PMID:27245949

  1. Space based astronomy: Teacher's guide with activities

    NASA Technical Reports Server (NTRS)

    Rosenberg, Carla B. (Editor); Weiler, Edward; Morrow, Cherilyn; Bacon, Pamela M.; Thorne, Muriel; Blanchard, Paul A.; Howard, Sethane; Pengra, Patricia R.; Brown, Deborah A.; Winrich, Ralph

    1994-01-01

    This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy - astronomical observations made from outer space. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. Instead, it tells the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. The guide begins with a survey of astronomy related NASA spacecraft. This is followed by a collection of activities in four units: (1) the atmospheric filter; (2) the electromagnetic spectrum; (3) collecting electromagnetic radiation; and (4) down to Earth. A curriculum index identifies the curriculum areas each activity addresses. The guide concludes with a glossary, reference list, a NASA Resources list, and an evaluation card. It is designed for students in grades 5 through 8.

  2. Activities of NICT space weather project

    NASA Astrophysics Data System (ADS)

    Murata, Ken T.; Nagatsuma, Tsutomu; Watari, Shinichi; Shinagawa, Hiroyuki; Ishii, Mamoru

    NICT (National Institute of Information and Communications Technology) has been in charge of space weather forecast service in Japan for more than 20 years. The main target region of the space weather is the geo-space in the vicinity of the Earth where human activities are dominant. In the geo-space, serious damages of satellites, international space stations and astronauts take place caused by energetic particles or electromagnetic disturbances: the origin of the causes is dynamically changing of solar activities. Positioning systems via GPS satellites are also im-portant recently. Since the most significant effect of positioning error comes from disturbances of the ionosphere, it is crucial to estimate time-dependent modulation of the electron density profiles in the ionosphere. NICT is one of the 13 members of the ISES (International Space Environment Service), which is an international assembly of space weather forecast centers under the UNESCO. With help of geo-space environment data exchanging among the member nations, NICT operates daily space weather forecast service every day to provide informa-tion on forecasts of solar flare, geomagnetic disturbances, solar proton event, and radio-wave propagation conditions in the ionosphere. The space weather forecast at NICT is conducted based on the three methodologies: observations, simulations and informatics (OSI model). For real-time or quasi real-time reporting of space weather, we conduct our original observations: Hiraiso solar observatory to monitor the solar activity (solar flare, coronal mass ejection, and so on), domestic ionosonde network, magnetometer HF radar observations in far-east Siberia, and south-east Asia low-latitude ionosonde network (SEALION). Real-time observation data to monitor solar and solar-wind activities are obtained through antennae at NICT from ACE and STEREO satellites. We have a middle-class super-computer (NEC SX-8R) to maintain real-time computer simulations for solar and solar

  3. Activities of the Space Studies Board

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This 1993 annual report of the Space Studies Board of the National research Council (NRC) describes the activities of the Board during a year filled with questions and change in the nation's civil space program. The accounts contained in this report briefly describe the activities of the Board and its committees and sketch out major space research issues. Two major reports are summarized, and the full text of three letter reports is included. Items considered include: (1) robotic missions to explore the Earth, the solar system, and the far reaches of the universe; (2) instability in the human flight program; (3) the redesign of the International Space Station; and (4) federal funding of research in all fields, especially basic research.

  4. Lightweight, Active Optics for Space and Near Space

    NASA Astrophysics Data System (ADS)

    Wick, D.; Bagwell, B.; Martinez, T.; Payne, D.; Restaino, S.; Romeo, R.

    Size, weight, and a lack of adaptability currently hinder the effectiveness of conventional imaging sensors in a number of military applications, including space-based space situational awareness (SSA), intelligence, surveillance, and reconnaissance (ISR), and missile tracking. The development of sensors that are smaller, lighter weight, adaptive, and use less power is critical for the success of future military initiatives. Threat detection systems need the flexibility of a wide FOV for surveillance and situational awareness while simultaneously maintaining high-resolution for target identification and precision tracking from a single, nonmechanical imaging system. Sandia National Laboratories, the Naval Research Laboratory, Narrascape, Inc., and Composite Mirror Applications, Inc. are at the forefront of active optics research, leading the development of active systems for foveated imaging, nonmechanical zoom, phase diversity, and actively enhanced multi-spectral imaging. Increasing the field-of-view, spatial resolution, spectral capability and system magnification have all been demonstrated with active optics. Adding active components to existing systems should significantly enhance capability in a number of military applications, including night vision, remote sensing and surveillance, chemical/biological detection, and large aperture, space-based systems. Deployment costs of large aperture systems in space or near-space are directly related to the weight of the system. In order to minimize the weight of conventional primary mirrors and simultaneously achieve an agile system that is capable of true optical zoom without macroscopic moving parts, we are proposing a revolutionary alternative to conventional telescopes where moving lenses/mirrors and gimbals are replaced with lightweight carbon fiber reinforced polymer (CFRP) variable radius-of-curvature mirrors (VRMs) and MEMS deformable mirrors (DMs). CFRP and MEMS DMs can provide a variable effective focal

  5. Economic benefits of commercial space activities

    NASA Technical Reports Server (NTRS)

    Stone, Barbara A.

    1988-01-01

    This paper discusses the current and potential impact on the economy of selected private sector space activities including materials processing in space and satellite communications. Spacehab, a commercially developed and manufactured pressurized metal cylinder which fits in the Shuttle payload bay and connects to the crew compartment is examined along with potential uses of the Shuttle external tank. Private sector upper stage development, the privatization of expendable launch vehicles, and the transfer of NASA technology are discussed.

  6. Environmental Impact Assessment and Space Activities

    NASA Astrophysics Data System (ADS)

    Viikari, L.

    these developments in way or another. In addition to national EIA regulations, there are also international agreements on EIA (i.a. the Espoo Convention) which establish their own EIA systems. In international law of outer space, environmental impact assessment is, however, not a well-established tool. The UN space treaties were drafted during a time when such consideratio ns were still not among the highest ranking items on national agendas. Therefore, these instruments fail to contain provisions regarding impact assessment, and also rest of the environmental content found in them is rather modest. The nearest equivalent to any impact assessment is contained in the Outer Space Treaty Article IX, namely the requirement of prior consultations in case of planned space activity or experiment that might cause "potentially harmful interference" with space activities of other St ates Parties. There also exist some applicable provisions on national level, such as the requirement of "formal assessment" on NASA programs of "[orbital] debris generation potential and debris mitigation options" in NASA Policy for Limiting Orbital Debris Generation (Art. 1.b). Also the national legislation of some space faring countries provides at least for the supply of some kind of information assessing the possible environmental consequences of proposed space activities. For instance, the Russian Statute on Lisencing Space Operations requires that for obtaining a license for space operation in the Russian Federation, the applicant has to supply, i.a. "documents confirming the safety of space operations (including ecological, fire and explosion safety) and the reliability of space equipment'"(Art.5.h). However, such provisions are obviously not enough for ensuring effective international regulation of the issue. The goal of this paper is to consider the usefulness of international environmental impact assessment for space activities. The space environment, however, is a unique arena in many ways

  7. Activities of the Space Studies Board

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Since its founding as the Space Science Board in 1958, the Space Studies Board has provided independent external scientific and technical advice on the nation's civil space program. This 1991 Annual Report of the SSB and its committees represents the first of its kind. The report contains a summary of the board's meetings, complete texts of letter reports, executive summaries of full reports issued during the year, and congressional testimony. It is intended to serve as a ready reference to board activities and advisory reports in 1991.

  8. Economic benefits of commercial space activities

    NASA Astrophysics Data System (ADS)

    Stone, Barbara A.

    Space is not only an endless frontier for exploration, but also a potentially rich arena for profitable commerce to benefit all mankind. Access to the unique environment of space provides opportunities for unprecedented kinds of research to develop new products and services. This research can lead to commercially viable enterprises, which will become permanent businesses, which will provide good jobs for workers, pay taxes to their governments, and return dividends to their investors. Seeking superior products and processes is vital if the economy is to grow and prosper. This paper discusses the current and potential impact on the economy of selected private sector space activities.

  9. Near-space airships against terrorist activities

    NASA Astrophysics Data System (ADS)

    Kesenek, Ceylan

    2014-06-01

    Near-space is a region surrounding the earth which is too dense for a satellite to fly and also too thin for air breathing vehicles to fly. The near-space region which is located between 65,000 and 325,000 feet is really underutilized despite its unique potential. Near-Space airships can be used to exploit the potential of near space. Such a system can supply not only a great deal of information using ISR (Intelligence Surveillance Reconnaissance) sensors on board but also serve as a communication/data relay. Airships used in near space can cover a very wide footprint area for surveillance missions. Free of orbital mechanics these near-space assets can continue its mission for long period of time with a persistence of days and months. These assets can provide persistent intelligence for fight against terrorist activities. Terrorism is a non-state threat and doesn't have a static hierarchical structure. To fight against such an adversary an overwhelming intelligence activity must be applied. Therefore, intelligence collection and surveillance missions play a vital role in counter terrorism. Terrorists use asymmetric means of threat that require information superiority. In this study exploitation of near space by airships is analyzed for fight against terrorism. Near-space airships are analyzed according to the operational effectiveness, logistic structure and cost. Advantages and disadvantages of airships are argued in comparison with satellites and airplanes. As a result, by bridging the gap between the air and space, nearspace airships are considered to be the most important asset of warfighter especially with its operational effectiveness.

  10. Conformational analysis of primary ethylene ozonide by gradient and multiconfigurational scf calculations

    NASA Astrophysics Data System (ADS)

    Ruoff, Peter; Almlöf, Jan; Sæbø, Svem

    1980-06-01

    Four conformers of ethylene primary ozonide have been studied by ab initio gradient and MC SCF calculations, using gaussian-type basis functions. The MC SCF results indicate that the conformers are not as close in energy as suggested from single-determinant SCF calculations. The oxygen-oxygen and carbon-oxygen half-chair structures are much lower in energy than the carbon-carbon half-chair.

  11. Assessment of the ΔSCF density functional theory approach for electronic excitations in organic dyes

    SciTech Connect

    Kowalczyk, T.; Yost, S. R.; Van Voorhis, T.

    2010-01-01

    This paper assesses the accuracy of the ΔSCF method for computing low-lying HOMO→LUMO transitions in organic dye molecules. For a test set of vertical excitation energies of 16 chromophores, surprisingly similar accuracy is observed for time-dependent density functional theory and for ΔSCF density functional theory. In light of this performance, we reconsider the ad hoc ΔSCF prescription and demonstrate that it formally obtains the exact stationary density within the adiabatic approximation, partially justifying its use. The relative merits and future prospects of ΔSCF for simulating individual excited states are discussed.

  12. Speeding up DFT: A faster method for integrating band energy in SCF cycles

    NASA Astrophysics Data System (ADS)

    Burbidge, Matthew M.; Jorgensen, Jeremy J.; Rosenbrock, Conrad W.; Thomas, Derek C.; Hess, Bret C.; Forcade, Rodney W.; Curtarolo, Stefano; Hart, Gus L. W.

    2015-03-01

    Typically in SCF cycles, a ``rectangle rule'' is used on uniformly spaced points (Monk Pack meshes)1 to integrate the band energy. The use of rectangles is motivated by their fast convergence when used on the fully occupied bands of semiconductors. Unfortunately integration with rectangles is extremely inefficient for metals. This motivates the use of gauss quadrature (or other higher order methods) for integrating the band energy. As we show, however, even in the case of semiconductors where the rectangle convergence is extremely efficient, higher order methods are still more efficient. The savings in semiconductors alone are sufficient to motivate the implementation of a higher order method in current DFT codes. Even though higher order quadrature methods were discussed immediately following the original Monkhorst and Pack1 paper, we revisit the issue in light of modern DFT calculations. MMB acknowledges support by NSF (DMR-0908753). JJJ, CWR, DCT, RWF, SC, GLWH was supported by ONR (MURI N00014-13-1-0635).

  13. Radiation protection for manned space activities

    NASA Technical Reports Server (NTRS)

    Jordan, T. M.

    1983-01-01

    The Earth's natural radiation environment poses a hazard to manned space activities directly through biological effects and indirectly through effects on materials and electronics. The following standard practices are indicated that address: (1) environment models for all radiation species including uncertainties and temporal variations; (2) upper bound and nominal quality factors for biological radiation effects that include dose, dose rate, critical organ, and linear energy transfer variations; (3) particle transport and shielding methodology including system and man modeling and uncertainty analysis; (4) mission planning that includes active dosimetry, minimizes exposure during extravehicular activities, subjects every mission to a radiation review, and specifies operational procedures for forecasting, recognizing, and dealing with large solar flaes.

  14. Hsk1- and SCF(Pof3)-dependent proteolysis of S. pombe Ams2 ensures histone homeostasis and centromere function.

    PubMed

    Takayama, Yuko; Mamnun, Yasmine M; Trickey, Michelle; Dhut, Susheela; Masuda, Fumie; Yamano, Hiroyuki; Toda, Takashi; Saitoh, Shigeaki

    2010-03-16

    Schizosaccharomyces pombe GATA factor Ams2 is responsible for cell cycle-dependent transcriptional activation of all the core histone genes peaking at G1/S phase. Intriguingly, its own protein level also fluctuates concurrently. Here, we show that Ams2 is ubiquitylated and degraded through the SCF (Skp1-Cdc53/Cullin-1-F-box) ubiquitin ligase, in which F box protein Pof3 binds this protein. Ams2 is phosphorylated at multiple sites, which is required for SCF(Pof3)-dependent proteolysis. Hsk1/Cdc7 kinase physically associates with and phosphorylates Ams2. Even mild overexpression of Ams2 induces constitutive histone expression and chromosome instability, and its toxicity is exaggerated when Hsk1 function is compromised. This is partly attributable to abnormal incorporation of canonical H3 into the central CENP-A/Cnp1-rich centromere, thereby reversing specific chromatin structures to apparently normal nucleosomes. We propose that Hsk1 plays a vital role during post S phase in genome stability via SCF(Pof3)-mediated degradation of Ams2, thereby maintaining centromere integrity. PMID:20230746

  15. Repression of ergosterol level during oxidative stress by fission yeast F-box protein Pof14 independently of SCF

    PubMed Central

    Tafforeau, Lionel; Le Blastier, Sophie; Bamps, Sophie; Dewez, Monique; Vandenhaute, Jean; Hermand, Damien

    2006-01-01

    We describe a new member of the F-box family, Pof14, which forms a canonical, F-box dependent SCF (Skp1, Cullin, F-box protein) ubiquitin ligase complex. The Pof14 protein has intrinsic instability that is abolished by inactivation of its Skp1 interaction motif (the F-box), Skp1 or the proteasome, indicating that Pof14 stability is controlled by an autocatalytic mechanism. Pof14 interacts with the squalene synthase Erg9, a key enzyme in ergosterol metabolism, in a membrane-bound complex that does not contain the core SCF components. pof14 transcription is induced by hydrogen peroxide and requires the Pap1 transcription factor and the Sty1 MAP kinase. Pof14 binds to and decreases Erg9 activity in vitro and a pof14 deletion strain quickly loses viability in the presence of hydrogen peroxide due to its inability to repress ergosterol synthesis. A pof14 mutant lacking the F-box and an skp1-3 ts mutant behave as wild type in the presence of oxidant showing that Pof14 function is independent of SCF. This indicates that modulation of ergosterol level plays a key role in adaptation to oxidative stress. PMID:17016471

  16. The ubiquitin conjugating enzyme UbcH10 competes with UbcH3 for binding to the SCF complex, a ubiquitin ligase involved in cell cycle progression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ubiquitylation, which regulates most biological pathways, occurs through an enzymatic cascade involving a ubiquitin (ub) activating enzyme (E1), a ub conjugating enzyme (E2) and a ub ligase (E3). UbcH3 is the E2 that interacts with SCF (Skp1/Cul1/F-box protein) complex and ubiquitylates many protein...

  17. Selection of active spaces for multiconfigurational wavefunctions

    NASA Astrophysics Data System (ADS)

    Keller, Sebastian; Boguslawski, Katharina; Janowski, Tomasz; Reiher, Markus; Pulay, Peter

    2015-06-01

    The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F2, ozone, and NO2), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr2). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions are discussed

  18. Selection of active spaces for multiconfigurational wavefunctions.

    PubMed

    Keller, Sebastian; Boguslawski, Katharina; Janowski, Tomasz; Reiher, Markus; Pulay, Peter

    2015-06-28

    The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F2, ozone, and NO2), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr2). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions are discussed

  19. Selection of active spaces for multiconfigurational wavefunctions

    SciTech Connect

    Keller, Sebastian; Boguslawski, Katharina; Reiher, Markus; Janowski, Tomasz; Pulay, Peter

    2015-06-28

    The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F{sub 2}, ozone, and NO{sub 2}), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr{sub 2}). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions

  20. Edible Earth and Space Science Activities

    NASA Astrophysics Data System (ADS)

    Lubowich, D.; Shupla, C.

    2014-07-01

    In this workshop we describe using Earth and Space Science demonstrations with edible ingredients to increase student interest. We show how to use chocolate, candy, cookies, popcorn, bagels, pastries, Pringles, marshmallows, whipped cream, and Starburst candy for activities such as: plate tectonics, the interior structure of the Earth and Mars, radioactivity/radioactive dating of rocks and stars, formation of the planets, lunar phases, convection, comets, black holes, curvature of space, dark energy, and the expansion of the Universe. In addition to creating an experience that will help students remember specific concepts, edible activities can be used as a formative assessment, providing students with the opportunity to create something that demonstrates their understanding of the model. The students often eat the demonstrations. These demonstrations are an effective teaching tool for all ages, and can be adapted for cultural, culinary, and ethnic differences among the students.

  1. BOOK REVIEW: Physics of Space Plasma Activity

    NASA Astrophysics Data System (ADS)

    Cramer, N. F.

    2007-11-01

    This book provides a timely review of our present understanding of plasma phenomena in magnetized terrestrial and solar space plasmas. The author's emphasis is on the fluid and particle modeling and interpretation of observed active processes in space plasmas, i.e. `the physical background of large plasma eruptions in space'. It is somewhat alarming for a plasma physicist to read that an emphasis on processes in spatially inhomogeneous plasmas means that the work `... excludes a considerable fraction of the available methods in space plasma physics, such as the theory of waves, instabilities and wave particle interactions on a homogeneous background', particularly in light of the fact that much of our knowledge of these plasmas is derived from observations of such waves. However, it is clear on reading the book that such a restriction is not a disadvantage, but allows the author to concentrate on the main theme of the book, namely the use of fluid and particle pictures to model the equilibrium and active states of space plasmas. There are many other books which cover the wave aspects of space plasmas, and would complement this book. The book's coverage is based on the extensive and profound research of the author and his colleagues in the area of fluid and particle modeling of space plasma structures. After an introduction to the physical setting of active plasmas, and a necessarily concise, but effective, discussion of the fluid and particle models to be used, the steady states of the magnetized plasmas of interest are treated, including the magnetosphere, solar plasmas and current sheets. Next the dynamics of unstable states is covered, including MHD and tearing instabilities, and nonlinear aspects, with a detailed discussion of magnetic reconnection. Finally, the models are applied to magnetospheric and solar observations. The book is attractively written and produced, and this reviewer managed to find a minimum number of errors. A particularly attractive

  2. Inhibition of SCF ubiquitin ligases by engineered ubiquitin variants that target the Cul1 binding site on the Skp1–F-box interface

    PubMed Central

    Gorelik, Maryna; Orlicky, Stephen; Sartori, Maria A.; Tang, Xiaojing; Marcon, Edyta; Kurinov, Igor; Greenblatt, Jack F.; Tyers, Mike; Moffat, Jason; Sicheri, Frank; Sidhu, Sachdev S.

    2016-01-01

    Skp1–Cul1–F-box (SCF) E3 ligases play key roles in multiple cellular processes through ubiquitination and subsequent degradation of substrate proteins. Although Skp1 and Cul1 are invariant components of all SCF complexes, the 69 different human F-box proteins are variable substrate binding modules that determine specificity. SCF E3 ligases are activated in many cancers and inhibitors could have therapeutic potential. Here, we used phage display to develop specific ubiquitin-based inhibitors against two F-box proteins, Fbw7 and Fbw11. Unexpectedly, the ubiquitin variants bind at the interface of Skp1 and F-box proteins and inhibit ligase activity by preventing Cul1 binding to the same surface. Using structure-based design and phage display, we modified the initial inhibitors to generate broad-spectrum inhibitors that targeted many SCF ligases, or conversely, a highly specific inhibitor that discriminated between even the close homologs Fbw11 and Fbw1. We propose that most F-box proteins can be targeted by this approach for basic research and for potential cancer therapies. PMID:26976582

  3. Membrane-bound human SCF/KL promotes in vivo human hematopoietic engraftment and myeloid differentiation

    PubMed Central

    Takagi, Shinsuke; Saito, Yoriko; Hijikata, Atsushi; Tanaka, Satoshi; Watanabe, Takashi; Hasegawa, Takanori; Mochizuki, Shinobu; Kunisawa, Jun; Kiyono, Hiroshi; Koseki, Haruhiko; Ohara, Osamu; Saito, Takashi; Taniguchi, Shuichi; Shultz, Leonard D.

    2012-01-01

    In recent years, advances in the humanized mouse system have led to significantly increased levels of human hematopoietic stem cell (HSC) engraftment. The remaining limitations in human HSC engraftment and function include lymphoid-skewed differentiation and inefficient myeloid development in the recipients. Limited human HSC function may partially be attributed to the inability of the host mouse microenvironment to provide sufficient support to human hematopoiesis. To address this problem, we created membrane-bound human stem cell factor (SCF)/KIT ligand (KL)–expressing NOD/SCID/IL2rgKO (hSCF Tg NSG) mice. hSCF Tg NSG recipients of human HSCs showed higher levels of both human CD45+ cell engraftment and human CD45+CD33+ myeloid development compared with NSG recipients. Expression of hSCF/hKL accelerated the differentiation of the human granulocyte lineage cells in the recipient bone marrow. Human mast cells were identified in bone marrow, spleen, and gastrointestinal tissues of the hSCF Tg NSG recipients. This novel in vivo humanized mouse model demonstrates the essential role of membrane-bound hSCF in human myeloid development. Moreover, the hSCF Tg NSG humanized recipients may facilitate investigation of in vivo differentiation, migration, function, and pathology of human mast cells. PMID:22279057

  4. An allosteric inhibitor of substrate recognition by the SCF[superscript Cdc4] ubiquitin ligase

    SciTech Connect

    Orlicky, Stephen; Tang, Xiaojing; Neduva, Victor; Elowe, Nadine; Brown, Eric D.; Sicheri, Frank; Tyers, Mike

    2010-09-17

    The specificity of SCF ubiquitin ligase-mediated protein degradation is determined by F-box proteins. We identified a biplanar dicarboxylic acid compound, called SCF-I2, as an inhibitor of substrate recognition by the yeast F-box protein Cdc4 using a fluorescence polarization screen to monitor the displacement of a fluorescein-labeled phosphodegron peptide. SCF-I2 inhibits the binding and ubiquitination of full-length phosphorylated substrates by SCF{sup Cdc4}. A co-crystal structure reveals that SCF-I2 inserts itself between the {beta}-strands of blades 5 and 6 of the WD40 propeller domain of Cdc4 at a site that is 25 {angstrom} away from the substrate binding site. Long-range transmission of SCF-I2 interactions distorts the substrate binding pocket and impedes recognition of key determinants in the Cdc4 phosphodegron. Mutation of the SCF-I2 binding site abrogates its inhibitory effect and explains specificity in the allosteric inhibition mechanism. Mammalian WD40 domain proteins may exhibit similar allosteric responsiveness and hence represent an extensive class of druggable target.

  5. Large active retrodirective arrays for space applications

    NASA Technical Reports Server (NTRS)

    Chernoff, R. C.

    1979-01-01

    An active retrodirective array (ARA) transmits a beam toward the apparent source of an illuminating signal called the pilot. The term active implies that the array produces, not merely reflects, RF power. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the conjugate of that received by the element. The problem of supplying the correct phase reference to the phase conjugation circuit (PCC) is solved by central phasing. A new form of central phasing suitable for very large arrays is outlined. ARAs may serve simultaneously as transmitting and receiving satellite antennas for space applications. Precision pointing and input-output isolation is provided by exact frequency-translating PCCs. A two-element ARA breadboard has been built and tested.

  6. U.S. commercial space activities - Returning the U.S. to preeminence in space

    NASA Technical Reports Server (NTRS)

    Stone, Barbara A.

    1987-01-01

    The current status of NASA's activities related to the commercial development of space is reviewed with particular reference to the emerging new commercial space activities and the post-Challenger policy developments affecting space commerce. The discussion covers the development of U.S. private sector launching capabilities, cooperative agreements with the private sector, the NASA technology utilization program, the technology applications activities of the Office of Commercial Programs, and the activities of the Centers for the Commercial Development of Space program.

  7. Development of a space activity suit

    NASA Technical Reports Server (NTRS)

    Annis, J. F.; Webb, P.

    1971-01-01

    The development of a series of prototype space activity suit (SAS) assemblies is discussed. The SAS is a new type of pressure suit designed especially for extravehicular activity. It consists of a set of carefully tailored elastic fabric garments which have been engineered to supply sufficient counterpressure to the body to permit subjects to breath O2 at pressures up to 200 mm Hg without circulatory difficulty. A closed, positive pressure breathing system (PPBS) and a full bubble helmet were also developed to complete the system. The ultimate goal of the SAS is to improve the range of activity and decrease the energy cost of work associated with wearing conventional gas filled pressure suits. Results are presented from both laboratory (1 atmosphere) and altitude chamber tests with subjects wearing various SAS assemblies. In laboratory tests lasting up to three hours, the SAS was worn while subjects breathed O2 at pressures up to 170 mm Hg without developing physiological problems. The only physiological symptoms apparent were a moderate tachycardia related to breathing pressures above 130 mm Hg, and a small collection of edema fluid in the hands. Both problems were considered to be related to areas of under-pressurization by the garments. These problems, it is suggested, can ultimately be corrected by the development of new elastic fabrics and tailoring techniques. Energy cost of activity, and mobility and dexterity of subjects in the SAS, were found to be superior to those in comparable tests on subjects in full pressure suits.

  8. ADEM-DIOS: an SCF convergence algorothm for difficult cases

    NASA Astrophysics Data System (ADS)

    Sellers, Harrell

    1991-05-01

    We present an SCF convergence algorithm which we call ADEM-DIOS for accelerated direct energy minimization-direct inversion in the optimized subspace. This method employs the direct energy minimization (steepest descent) procedure outlined by Seeger and Pople to generate a set of "optimized" approximate solutions that form a basis for a least squares interpolation based on the DIIS method of Pulay. In all of our test cases, which we chose because damped Roothaan—Hall iterations, ordinary DIIS, level shifting, and variable metric second-order optimization failed to bring about convergence, the ADEM-DIOS method achieved convergence in a fraction of the number of steps required when direct energy minimization was used alone. This method can be thought of as being essentially the DIIS convergence acceleration technique applied to an "iterative subspace" generated by the direct energy minimization procedure. While we do not expect ADEM-DIOS to be significantly faster per cycle than second-order optimization algorithms based on Bacskay's method, the convergence ability of ADEM-DIOS is insensitive to the initial parameter set and should be more applicable in difficult cases. We consider th usefulness of this new algorithm to be in those cases in which other algorithms have difficulty in achieving convergence.

  9. Actively controlled thin-shell space optics

    NASA Astrophysics Data System (ADS)

    Denoyer, Keith K.; Flint, Eric M.; Main, John A.; Lindler, Jason E.

    2003-08-01

    Increasingly, scientific and military missions require the use of space-based optical systems. For example, new capabilities are required for imaging terrestrial like planets, for surveillance, and for directed energy applications. Given the difficulties in producing and launching large optics, it is doubtful that refinements of conventional technology will meet future needs, particularly in a cost-effective manner. To meet this need, recent research has been investigating the feasibility of a new class of ultra-lightweight think-skin optical elements that combine recent advances in lightweight thermally formed materials, active materials, and novel sensing and control architectures. If successful, the approach may lead to an order of magnitude reduction in space optics areal density, improved large scale manufacturing capability, and dramatic reductions in manufacturing and launch costs. In a recent effort, a one meter thin-film mirror like structure was fabricated. This paper provides an overview of tools used to model and simulate this structure as well as results from structural dynamic testing. In addition, progress in the area of non-contact global shape control using smart materials is presented.

  10. Refining the thermodynamic functions of scandium triflouride ScF3 in the condensed state

    NASA Astrophysics Data System (ADS)

    Aristova, N. M.; Belov, G. V.

    2016-03-01

    Refined thermodynamic functions (entropy, enthalpy increments, and reduced Gibbs energy) of scandium trifluoride ScF3 in the crystalline and liquid states in the temperature range 5-2500 K are presented.

  11. Space Industrialization: Manufacturing and Construction Activities. Part 2.

    ERIC Educational Resources Information Center

    Story, Charles H.

    1983-01-01

    Discusses how space industrialization will provide direct benefits for our nation and will transfer technology to the many diverse areas of human activity. Examples are the development of the Space Shuttle, the Space Studies Institute, and the LS Society (advocates for colonizing space). (NRJ)

  12. SCF increases in utero-labeled stem cells migration and improves wound healing.

    PubMed

    Zgheib, Carlos; Xu, Junwang; Mallette, Andrew C; Caskey, Robert C; Zhang, Liping; Hu, Junyi; Liechty, Kenneth W

    2015-01-01

    Diabetic skin wounds lack the ability to heal properly and constitute a major and significant complication of diabetes. Nontraumatic lower extremity amputations are the number one complication of diabetic skin wounds. The complexity of their pathophysiology requires an intervention at many levels to enhance healing and wound closure. Stem cells are a promising treatment for diabetic skin wounds as they have the ability to correct abnormal healing. Stem cell factor (SCF), a chemokine expressed in the skin, can induce stem cells migration, however the role of SCF in diabetic skin wound healing is still unknown. We hypothesize that SCF would correct the impairment and promote the healing of diabetic skin wounds. Our results show that SCF improved wound closure in diabetic mice and increased HIF-1α and vascular endothelial growth factor (VEGF) expression levels in these wounds. SCF treatment also enhanced the migration of red fluorescent protein (RFP)-labeled skin stem cells via in utero intra-amniotic injection of lenti-RFP at E8. Interestingly these RFP+ cells are present in the epidermis, stain negative for K15, and appear to be distinct from the already known hair follicle stem cells. These results demonstrate that SCF improves diabetic wound healing in part by increasing the recruitment of a unique stem cell population present in the skin. PMID:26032674

  13. 7. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, IN SPACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, IN SPACE SUIT AFTER TESTING IN NEUTRAL BUOYANCY TANK. AVERAGE COST OF SUIT IS $1,000,000. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  14. Pharmacological inactivation of Skp2 SCF ubiquitin ligase restricts cancer stem cell traits and cancer progression

    PubMed Central

    Chan, Chia-Hsin; Morrow, John Kenneth; Li, Chien-Feng; Gao, Yuan; Jin, Guoxiang; Moten, Asad; Stagg, Loren J.; Ladbury, John E.; Cai, Zhen; Xu, Dazhi; Logothetis, Christopher J.; Hung, Mien-Chie; Zhang, Shuxing; Lin, Hui-Kuan

    2013-01-01

    Skp2 E3 ligase is overexpressed in numerous human cancers and plays a critical role in cell cycle progression, senescence, metabolism, cancer progression and metastasis. In the present study, we identified a specific Skp2 inhibitor using high-throughput in silico screening of large and diverse chemical libraries. This Skp2 inhibitor selectively suppresses Skp2 E3 ligase activity, but not activity of other SCF complexes. It also phenocopies the effects observed upon genetic Skp2 deficiency, such as suppressing survival, Akt-mediated glycolysis as well as triggering p53-independent cellular senescence. Strikingly, we discovered a critical function of Skp2 in positively regulating cancer stem cell populations and self-renewal ability through genetic and pharmacological approaches. Notably, Skp2 inhibitor exhibits potent anti-tumor activities in multiple animal models and cooperates with chemotherapeutic agents to reduce cancer cell survival. Our study thus provides pharmacological evidence that Skp2 is a promising target for restricting cancer stem cell and cancer progression. PMID:23911321

  15. International Space Station (ISS) Risk Reduction Activities

    NASA Technical Reports Server (NTRS)

    Fodroci, Michael

    2011-01-01

    As the assembly of the ISS nears completion, it is worthwhile to step back and review some of the actions pursued by the Program in recent years to reduce risk and enhance the safety and health of ISS crewmembers, visitors, and space flight participants. While the ISS requirements and initial design were intended to provide the best practicable levels of safety, it is always possible to reduce risk -- given the determination and commitment to do so. The following is a summary of some of the steps taken by the ISS Program Manager, by our International Partners, by hardware and software designers, by operational specialists, and by safety personnel to continuously enhance the safety of the ISS. While decades of work went into developing the ISS requirements, there are many things in a Program like the ISS that can only be learned through actual operational experience. These risk reduction activities can be divided into roughly three categories: (1) Areas that were initially noncompliant which have subsequently been brought into compliance or near compliance (i.e., Micrometeoroid and Orbital Debris [MMOD] protection, acoustics) (2) Areas where initial design requirements were eventually considered inadequate and were subsequently augmented (i.e., Toxicity Level 4 materials, emergency hardware and procedures) (3) Areas where risks were initially underestimated, and have subsequently been addressed through additional mitigation (i.e., Extravehicular Activity [EVA] sharp edges, plasma shock hazards) Due to the hard work and cooperation of many parties working together across the span of nearly a decade, the ISS is now a safer and healthier environment for our crew, in many cases exceeding the risk reduction targets inherent in the intent of the original design. It will provide a safe and stable platform for utilization and discovery.

  16. Aeronautics and space report of the president, 1974 activities

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The U.S. Government activities for 1974 in aeronautics and space are presented. Significant contributions toward the fulfillment of the nation's goals in space and aeronautics are covered, including application of space systems and technology to beneficial uses on earth, exploration of space and increase of scientific knowledge, development of improved space systems and technology, international cooperation, and advancement of civil and military aeronautics. Also in 1974, space activities in the private sector expanded to provide additional services to the public. The accomplishments are summarized.

  17. Time-dependent restricted-active-space self-consistent-field singles method for many-electron dynamics

    SciTech Connect

    Miyagi, Haruhide; Bojer Madsen, Lars

    2014-04-28

    The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ⩽ M ⩽ N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.

  18. Aeronautics and space report of the President, 1982 activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included.

  19. Telerobotic activities at Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Price, Charles R.

    1989-01-01

    The Johnson Space Center telerobotic efforts span three major thrusts: (1) sustaining and expanding the capability of the Shuttle manipulator; (2) developing and integrating the multiple telerobotic system of the Space Station; and (3) fostering and applying research in all areas of telerobotics technology within the government, private, and academic sectors.

  20. Activities of the Center for Space Construction

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Center for Space Construction (CSC) at the University of Colorado at Boulder is one of eight University Space Engineering Research Centers established by NASA in 1988. The mission of the center is to conduct research into space technology and to directly contribute to space engineering education. The center reports to the Department of Aerospace Engineering Sciences and resides in the College of Engineering and Applied Science. The college has a long and successful track record of cultivating multi-disciplinary research and education programs. The Center for Space Construction is prominent evidence of this record. At the inception of CSC, the center was primarily founded on the need for research on in-space construction of large space systems like space stations and interplanetary space vehicles. The scope of CSC's research has now evolved to include the design and construction of all spacecraft, large and small. Within this broadened scope, our research projects seek to impact the underlying technological basis for such spacecraft as remote sensing satellites, communication satellites, and other special purpose spacecraft, as well as the technological basis for large space platforms. The center's research focuses on three areas: spacecraft structures, spacecraft operations and control, and regolith and surface systems. In the area of spacecraft structures, our current emphasis is on concepts and modeling of deployable structures, analysis of inflatable structures, structural damage detection algorithms, and composite materials for lightweight structures. In the area of spacecraft operations and control, we are continuing our previous efforts in process control of in-orbit structural assembly. In addition, we have begun two new efforts in formal approach to spacecraft flight software systems design and adaptive attitude control systems. In the area of regolith and surface systems, we are continuing the work of characterizing the physical properties of lunar

  1. Activity Space Environment and Dietary and Physical Activity Behaviors: A Pilot Study

    PubMed Central

    Zenk, Shannon N.; Schulz, Amy J.; Matthews, Stephen A.; Odoms-Young, Angela; Wilbur, JoEllen; Wegrzyn, Lani; Gibbs, Kevin; Braunschweig, Carol; Stokes, Carmen

    2011-01-01

    This study examined relationships among individual demographics, environmental features (e.g., fast food outlet density, park land use) of residential neighborhoods and activity spaces, and obesity-related behaviors (diet, physical activity). Participants’ movement was tracked for seven days using global positioning systems (GPS). Two activity space measures (one standard deviation ellipse, daily path area) were derived from the GPS data. Activity spaces were generally larger than residential neighborhoods; environmental features of residential neighborhoods and activity spaces were weakly associated; and some activity space environmental features were related to dietary behaviors. Activity spaces may provide new insights into environmental influences on obesity-related behaviors. PMID:21696995

  2. Increased SCF/c-kit by hypoxia promotes autophagy of human placental chorionic plate-derived mesenchymal stem cells via regulating the phosphorylation of mTOR.

    PubMed

    Lee, Youjin; Jung, Jieun; Cho, Kyung Jin; Lee, Seoung-Kwan; Park, Jong-Wan; Oh, Il-Hoan; Kim, Gi Jin

    2013-01-01

    Hypoxia triggers physiological and pathological cellular processes, including proliferation, differentiation, and death, in several cell types. Mesenchymal stem cells (MSCs) derived from various tissues have self-renewal activity and can differentiate towards multiple lineages. Recently, it has been reported that hypoxic conditions tip the balance between survival and death by hypoxia-induced autophagy, although the underlying mechanism is not clear. The objectives of this study are to compare the effect of hypoxia on the self-renewal of bone marrow-derived mesenchymal stem cells (BM-MSCs) and placental chorionic plate-derived mesenchymal stem cells (CP-MSCs) and to investigate the regulatory mechanisms of self-renewal in each MSC type during hypoxia. The expression of self-renewal markers (e.g., Oct4, Nanog, Sox2) was assessed in both cell lines. PI3K and stem cell factor (SCF) expression gradually increased in CP-MSCs but were markedly downregulated in BM-MSCs by hypoxia. The phosphorylation of ERK and mTOR was augmented by hypoxia in CP-MSCs compared to control. Also, the expression of LC3 II, a component of the autophagosome and the hoof-shaped autophagosome was detected more rapidly in CP-MSCs than in BM-MSCs under hypoxia. Hypoxia induced the expression of SCF in CP-MSCs and increased SCF/c-kit pathway promotes the self-renewal activities of CP-MSCs via an autocrine/paracrine mechanism that balances cell survival and cell death events by autophagy. These activities occur to a greater extent in CP-MSCs than in BM-MSCs through regulating the phosphorylation of mTOR. These findings will provide useful guidelines for better understanding the function of SCF/c-kit in the self-renewal and autophagy-regulated mechanisms that promote of MSC survival. PMID:22833529

  3. Space station group activities habitability module study

    NASA Technical Reports Server (NTRS)

    Nixon, David

    1986-01-01

    This study explores and analyzes architectural design approaches for the interior of the Space Station Habitability Module (originally defined as Habitability Module 1 in Space Station Reference Configuration Decription, JSC-19989, August 1984). In the Research Phase, architectural program and habitability design guidelines are specified. In the Schematic Design Phase, a range of alternative concepts is described and illustrated with drawings, scale-model photographs and design analysis evaluations. Recommendations are presented on the internal architectural, configuration of the Space Station Habitability Module for such functions as the wardroom, galley, exercise facility, library and station control work station. The models show full design configurations for on-orbit performance.

  4. SCF(β-TRCP) promotes cell growth by targeting PR-Set7/Set8 for degradation.

    PubMed

    Wang, Zhiwei; Dai, Xiangpeng; Zhong, Jiateng; Inuzuka, Hiroyuki; Wan, Lixin; Li, Xiaoning; Wang, Lixia; Ye, Xiantao; Sun, Liankun; Gao, Daming; Zou, Lee; Wei, Wenyi

    2015-01-01

    The Set8/PR-Set7/KMT5a methyltransferase plays critical roles in governing transcriptional regulation, cell cycle progression and tumorigenesis. Although CRL4(Cdt2) was reported to regulate Set8 stability, deleting the PIP motif only led to partial resistance to ultraviolet-induced degradation of Set8, indicating the existence of additional E3 ligase(s) controlling Set8 stability. Furthermore, it remains largely undefined how DNA damage-induced kinase cascades trigger the timely destruction of Set8 to govern tumorigenesis. Here, we report that SCF(β-TRCP) earmarks Set8 for ubiquitination and degradation in a casein kinase I-dependent manner, which is activated by DNA-damaging agents. Biologically, both CRL4(Cdt2) and SCF(β-TRCP)-mediated pathways contribute to ultraviolet-induced Set8 degradation to control cell cycle progression, governing the onset of DNA damage-induced checkpoints. Therefore, like many critical cell cycle regulators including p21 and Cdt1, we uncover a tight regulatory network to accurately control Set8 abundance. Our studies further suggest that aberrancies in this delicate degradation pathway might contribute to aberrant elevation of Set8 in human tumours. PMID:26666832

  5. Individualized Instruction in Science, Earth Space Project, Learning Activities Package.

    ERIC Educational Resources Information Center

    Kuczma, R. M.

    Learning Activity Packages (LAP) relating to the earth and space are presented for use in sampling a new type of learning for a whole year. Eighteen topics are incorporated into five units: (1) introduction to individualized learning, (2) observation versus interpretation, (3) chemistry in the space age, (4) the space age interdisciplines, and (5)…

  6. Space Adaptation of Active Mirror Segment Concepts

    NASA Technical Reports Server (NTRS)

    Ames, Gregory H.

    1999-01-01

    This report summarizes the results of a three year effort by Blue Line Engineering Co. to advance the state of segmented mirror systems in several separate but related areas. The initial set of tasks were designed to address the issues of system level architecture, digital processing system, cluster level support structures, and advanced mirror fabrication concepts. Later in the project new tasks were added to provide support to the existing segmented mirror testbed at Marshall Space Flight Center (MSFC) in the form of upgrades to the 36 subaperture wavefront sensor. Still later, tasks were added to build and install a new system processor based on the results of the new system architecture. The project was successful in achieving a number of important results. These include the following most notable accomplishments: 1) The creation of a new modular digital processing system that is extremely capable and may be applied to a wide range of segmented mirror systems as well as many classes of Multiple Input Multiple Output (MIMO) control systems such as active structures or industrial automation. 2) A new graphical user interface was created for operation of segmented mirror systems. 3) The development of a high bit rate serial data loop that permits bi-directional flow of data to and from as many as 39 segments daisy-chained to form a single cluster of segments. 4) Upgrade of the 36 subaperture Hartmann type Wave Front Sensor (WFS) of the Phased Array Mirror, Extendible Large Aperture (PAMELA) testbed at MSFC resulting in a 40 to 5OX improvement in SNR which in turn enabled NASA personnel to achieve many significant strides in improved closed-loop system operation in 1998. 5) A new system level processor was built and delivered to MSFC for use with the PAMELA testbed. This new system featured a new graphical user interface to replace the obsolete and non-supported menu system originally delivered with the PAMELA system. The hardware featured Blue Line's new stackable

  7. SCF (Fbxl17) ubiquitylation of Sufu regulates Hedgehog signaling and medulloblastoma development.

    PubMed

    Raducu, Madalina; Fung, Ella; Serres, Sébastien; Infante, Paola; Barberis, Alessandro; Fischer, Roman; Bristow, Claire; Thézénas, Marie-Laëtitia; Finta, Csaba; Christianson, John C; Buffa, Francesca M; Kessler, Benedikt M; Sibson, Nicola R; Di Marcotullio, Lucia; Toftgård, Rune; D'Angiolella, Vincenzo

    2016-07-01

    Skp1-Cul1-F-box protein (SCF) ubiquitin ligases direct cell survival decisions by controlling protein ubiquitylation and degradation. Sufu (Suppressor of fused) is a central regulator of Hh (Hedgehog) signaling and acts as a tumor suppressor by maintaining the Gli (Glioma-associated oncogene homolog) transcription factors inactive. Although Sufu has a pivotal role in Hh signaling, the players involved in controlling Sufu levels and their role in tumor growth are unknown. Here, we show that Fbxl17 (F-box and leucine-rich repeat protein 17) targets Sufu for proteolysis in the nucleus. The ubiquitylation of Sufu, mediated by Fbxl17, allows the release of Gli1 from Sufu for proper Hh signal transduction. Depletion of Fbxl17 leads to defective Hh signaling associated with an impaired cancer cell proliferation and medulloblastoma tumor growth. Furthermore, we identify a mutation in Sufu, occurring in medulloblastoma of patients with Gorlin syndrome, which increases Sufu turnover through Fbxl17-mediated polyubiquitylation and leads to a sustained Hh signaling activation. In summary, our findings reveal Fbxl17 as a novel regulator of Hh pathway and highlight the perturbation of the Fbxl17-Sufu axis in the pathogenesis of medulloblastoma. PMID:27234298

  8. Endocytic trafficking towards the vacuole plays a key role in the auxin receptor SCF(TIR)-independent mechanism of lateral root formation in A. thaliana.

    PubMed

    Pérez-Henríquez, Patricio; Raikhel, Natasha V; Norambuena, Lorena

    2012-11-01

    Plants' developmental plasticity plays a pivotal role in responding to environmental conditions. One of the most plastic plant organs is the root system. Different environmental stimuli such as nutrients and water deficiency may induce lateral root formation to compensate for a low level of water and/or nutrients. It has been shown that the hormone auxin tunes lateral root development and components for its signaling pathway have been identified. Using chemical biology, we discovered an Arabidopsis thaliana lateral root formation mechanism that is independent of the auxin receptor SCF(TIR). The bioactive compound Sortin2 increased lateral root occurrence by acting upstream from the morphological marker of lateral root primordium formation, the mitotic activity. The compound did not display auxin activity. At the cellular level, Sortin2 accelerated endosomal trafficking, resulting in increased trafficking of plasma membrane recycling proteins to the vacuole. Sortin2 affected Late endosome/PVC/MVB trafficking and morphology. Combining Sortin2 with well-known drugs showed that endocytic trafficking of Late E/PVC/MVB towards the vacuole is pivotal for Sortin2-induced SCF(TIR)-independent lateral root initiation. Our results revealed a distinctive role for endosomal trafficking in the promotion of lateral root formation via a process that does not rely on the auxin receptor complex SCF(TIR). PMID:22848095

  9. The SCF-FBXW5 E3-ubiquitin ligase is regulated by PLK4 and targets HsSAS-6 to control centrosome duplication.

    PubMed

    Puklowski, Anja; Homsi, Yahya; Keller, Debora; May, Martin; Chauhan, Sangeeta; Kossatz, Uta; Grünwald, Viktor; Kubicka, Stefan; Pich, Andreas; Manns, Michael P; Hoffmann, Ingrid; Gönczy, Pierre; Malek, Nisar P

    2011-08-01

    Deregulated centrosome duplication can result in genetic instability and contribute to tumorigenesis. Here, we show that centrosome duplication is regulated by the activity of an E3-ubiquitin ligase that employs the F-box protein FBXW5 (ref. 3) as its targeting subunit. Depletion of endogenous FBXW5 or overexpression of an F-box-deleted mutant version results in centrosome overduplication and formation of multipolar spindles. We identify the centriolar protein HsSAS-6 (refs 4,5) as a critical substrate of the SCF-FBXW5 complex. FBXW5 binds HsSAS-6 and promotes its ubiquitylation in vivo. The activity of SCF-FBXW5 is in turn negatively regulated by Polo-like kinase 4 (PLK4), which phosphorylates FBXW5 at Ser 151 to suppress its ability to ubiquitylate HsSAS-6. FBXW5 is a cell-cycle-regulated protein with expression levels peaking at the G1/S transition. We show that FBXW5 levels are controlled by the anaphase-promoting (APC/C) complex, which targets FBXW5 for degradation during mitosis and G1, thereby helping to reset the centrosome duplication machinery. In summary, we show that a cell-cycle-regulated SCF complex is regulated by the kinase PLK4, and that this in turn restricts centrosome re-duplication through degradation of the centriolar protein HsSAS-6. PMID:21725316

  10. Physics of Colloids in Space: Microgravity Experiment Launched, Installed, and Activated on the International Space Station

    NASA Technical Reports Server (NTRS)

    Doherty, Michael P.

    2002-01-01

    The Physics of Colloids in Space (PCS) experiment is a Microgravity Fluids Physics investigation that is presently located in an Expedite the Process of Experiments to Space Station (EXPRESS) Rack on the International Space Station. PCS was launched to the International Space Station on April 19, 2001, activated on May 31, 2001, and will continue to operate about 90 hr per week through May 2002.

  11. Space Activism as an Epiphanic Belief System

    NASA Technical Reports Server (NTRS)

    Mendell, Wendell

    2006-01-01

    Years of interaction with young people in the space industry and in space activists groups led to my observation that many such individuals can cite a quite specific life event that triggered a life-long interest in or commitment to creating a space future. I am particularly intrigued by parallels between such experiences and the phenomenon of epiphanic experiences among committed Christians. I see analogies between the puzzlement among space activists and among Christian groups as to the reasons for so many people being "unbelievers." At a small international meeting on lunar exploration in 2003, I heard two separate lunch speakers cite such personal experiences. At the beginning of a break in that meeting, I grabbed the microphone from the chairman and asked each person to write down on a pad by his chair whether or not he (or she) had experienced a specific event that led to their involvement in space. If the answer was positive, I asked for a brief narrative, for their age at the time, and for their current age. I received 53 submissions, 20% of which simply stated that their involvement in space exploration was happenstance. (Apollo astronaut John Young was among these.) The other 80% of the submissions had specific stories. The ages at the time of the epiphany ranged from 4 to 47; and their current ages ranged from 22 to 78. I will present a high-level characterization of these inputs. Interest in space exploration as a form of belief system is consistent with choosing NASA goals for the purpose of inspiration and with phenomena such as the "Overview Effect". More research might explore what form the transcendent experience takes and whether it might be associated with feelings of universal connection such as the noosphere or "The Force". From a pragmatic point of view, outreach strategies for exploration should focus on giving individuals access to personal, potentially transformational experiences as opposed to astronaut talks at civic clubs.

  12. Interrupted E2F1-miR-34c-SCF negative feedback loop by hyper-methylation promotes colorectal cancer cell proliferation

    PubMed Central

    Yang, Shu; Wu, Bo; Sun, Haimei; Ji, Fengqing; Sun, Tingyi; Zhao, Yan; Zhou, Deshan

    2015-01-01

    Tumour suppressor miR-34c deficiency resulted from hyper-methylation in its promoter is believed to be one of the main causes of colorectal cancer (CRC). Till date, miR-34c has been validated as a direct target of p53; but previous evidence suggested other transcription factor(s) must be involved in miR-34c transcription. In the present study, we in the first place identified a core promoter region (−1118 to −883 bp) of pre-miR-34c which was embedded within a hyper-methylated CpG island. Secondly, E2F1 promoted miR-34c transcription by physical interaction with the miR-34c promoter at site −897 to −889 bp. The transcriptional activating effect of E2F1 on miR-34c was in a p53 independent manner but profoundly promoted in the presence of p53 with exposure to 5-aza-2′-deoxycytidine (DAC). Thirdly, stem cell factor (SCF), a miR-34c target, was specifically reduced upon an introduction of E2F1 which lead to suppression of CRC cell proliferation. The E2F1-suppressed cell proliferation was partially abrogated by additional miR-34c inhibitor, indicating that the anti-proliferation effect of E2F1 was probably through activating miR-34c-SCF axis. Finally, SCF/KIT signalling increased E2F1 production by reducing its proteosomal degradation dependent on PI3K/Akt-GSK3β pathway. In conclusion, our results suggested the existence of E2F1-miR-34c-SCF negative feedback loop which was interrupted by the hyper-methylation of miR-34c promoter in CRC cells and increased cell proliferation. PMID:26704889

  13. Aeronautics and Space Report of the President: 1975 Activities.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This report, submitted to the Congress by President Ford in accordance with the National Aeronautics and Space Act of 1958, summarizes the United States' space and aeronautics activities for the year 1975. Detailed summaries of the activities of the following governmental departments or agencies are provided: National Aeronautics and Space…

  14. Covalent modifier NEDD8 is essential for SCF ubiquitin-ligase in fission yeast.

    PubMed

    Osaka, F; Saeki, M; Katayama, S; Aida, N; Toh-E, A; Kominami, K; Toda, T; Suzuki, T; Chiba, T; Tanaka, K; Kato, S

    2000-07-01

    A ubiquitin-like modifier, NEDD8, is covalently attached to cullin-family proteins, but its physiological role is poorly understood. Here we report that the NEDD8-modifying pathway is essential for cell viability and function of Pcu1 (cullin-1 orthologue) in fission yeast. Pcu1 assembled on SCF ubiquitin-ligase was completely modified by NEDD8. Pcu1(K713R) defective for NEDD8 conjugation lost the ability to complement lethality due to pcu1 deletion. Forced expression of Pcu1(K713R) or depletion of NEDD8 in cells resulted in impaired cell proliferation and marked stabilization of the cyclin-dependent kinase inhibitor Rum1, which is a substrate of the SCF complex. Based on these findings, we propose that covalent modification of cullin-1 by the NEDD8 system plays an essential role in the function of SCF in fission yeast. PMID:10880460

  15. Stem Cell Factor (SCF) is a putative biomarker of antidepressant response.

    PubMed

    Benedetti, Francesco; Poletti, Sara; Hoogenboezem, Thomas A; Locatelli, Clara; Ambrée, Oliver; de Wit, Harm; Wijkhuijs, Annemarie J M; Mazza, Elena; Bulgarelli, Chiara; Vai, Benedetta; Colombo, Cristina; Smeraldi, Enrico; Arolt, Volker; Drexhage, Hemmo A

    2016-06-01

    Growth factors involved in neurogenesis and neuroplasticity could play a role in biological processes that drive depression recovery. Combined total sleep deprivation and morning light therapy (TSD + LT) can acutely reverse depressive symptoms, thus allowing to investigate the neurobiological correlates of antidepressant response. We tested if changes on plasma levels of Brain Derived Neurotrophic Factor (BDNF), S100 calcium binding protein B (S100-B), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF), Platelet-Derived Growth Factor-BB (PDGF-BB), and Vascular Endothelial Growth Factor (VEGF) are associated with response to TSD + LT in 26 inpatients affected by a major depressive episode in the course of bipolar disorder. Regional grey matter (GM) volumes were assessed at baseline, and BOLD fMRI neural responses to a moral valence decision task were recorded before and after treatment. 61.5 % of patients responded to treatment. SCF plasma levels increased significantly more in responders, and correlated with GM volumes in frontal and parietal cortical areas. The pattern of change of SCF also associated with both GM volumes and changes of BOLD fMRI neural responses in the anterior cingulate and medial prefrontal cortex. SCF is both a hematopoietic growth factor and a neurotrophic factor, involved in neuron-neuron and neuron-(micro) glia interactions, fostering neuronal growth and an anti-inflammatory milieu. We correlated SCF levels with antidepressant response and with functional and structural MRI measures in cortical areas that are involved in the cognitive generation and control of affect. SCF may be a candidate growth factor that contributes to neurotrophic and immune effects that are involved in the process of remission/recovery from depression. PMID:27108110

  16. Non–SCF-type F-box protein Roy1/Ymr258c interacts with a Rab5-like GTPase Ypt52 and inhibits Ypt52 function

    PubMed Central

    Liu, Yuan; Nakatsukasa, Kunio; Kotera, Michiko; Kanada, Akira; Nishimura, Takashi; Kishi, Tsutomu; Mimura, Satoru; Kamura, Takumi

    2011-01-01

    Skp1/Cul1/F-box (SCF)–type F-box proteins are a component of the Cullin-RING SCF ubiquitin E3 ligase, which is involved in numerous cellular processes. However, the function of non–SCF-type F-box proteins remains largely unknown. The Rab5-like small guanosine 5′-triphosphatase Vps21/Ypt51 is a key regulator of intracellular transportation; however, deletion of its isoforms, Ypt52 and Ypt53, results in only a modest inhibition of intracellular trafficking. The function of these proteins therefore remains largely elusive. Here we analyze the role of a previously uncharacterized non–SCF-type F-box protein, Roy1/Ymr258c, in cell growth and intracellular transport in Saccharomyces cerevisiae. Roy1 binds to Ypt52 under physiological conditions, and Skp1 is indispensable for the association of Roy1 with Ypt52. The vps21Δ yeast cells exhibit severe deficiencies in cell growth and intracellular trafficking, whereas simultaneous deletion of roy1 alleviates the defects caused by deletion of vps21. However, additional disruption of ypt52 in roy1Δvps21Δ cells largely suppresses the cell growth and trafficking observed in roy1Δvps21Δ cells. We demonstrate that Roy1 interacts with guanosine 5′-diphosphate–bound and nucleotide-free Ypt52 and thereby inhibits the formation of guanosine 5′-triphosphate–bound, active Ypt52. These results thus indicate that Roy1 negatively modulates cell viability and intracellular transport by suppressing Ypt52. PMID:21389113

  17. Qualitative GIS and the Visualization of Narrative Activity Space Data

    PubMed Central

    Mennis, Jeremy; Mason, Michael J.; Cao, Yinghui

    2012-01-01

    Qualitative activity space data, i.e. qualitative data associated with the routine locations and activities of individuals, are recognized as increasingly useful by researchers in the social and health sciences for investigating the influence of environment on human behavior. However, there has been little research on techniques for exploring qualitative activity space data. This research illustrates the theoretical principles of combining qualitative and quantitative data and methodologies within the context of GIS, using visualization as the means of inquiry. Through the use of a prototype implementation of a visualization system for qualitative activity space data, and its application in a case study of urban youth, we show how these theoretical methodological principles are realized in applied research. The visualization system uses a variety of visual variables to simultaneously depict multiple qualitative and quantitative attributes of individuals’ activity spaces. The visualization is applied to explore the activity spaces of a sample of urban youth participating in a study on the geographic and social contexts of adolescent substance use. Examples demonstrate how the visualization may be used to explore individual activity spaces to generate hypotheses, investigate statistical outliers, and explore activity space patterns among subject subgroups. PMID:26190932

  18. Low-cost Active Structural Control Space Experiment (LASC)

    NASA Technical Reports Server (NTRS)

    Robinett, Rush; Bukley, Angelia P.

    1992-01-01

    The DOE Lab Director's Conference identified the need for the DOE National Laboratories to actively and aggressively pursue ways to apply DOE technology to problems of national need. Space structures are key elements of DOD and NASA space systems and a space technology area in which DOE can have a significant impact. LASC is a joint agency space technology experiment (DOD Phillips, NASA Marshall, and DOE Sandia). The topics are presented in viewgraph form and include the following: phase 4 investigator testbed; control of large flexible structures in orbit; INFLEX; Controls, Astrophysics; and structures experiments in space; SARSAT; and LASC mission objectives.

  19. Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

    NASA Astrophysics Data System (ADS)

    Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

    Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

  20. The Global Space Geodesy Network: Activities Underway

    NASA Astrophysics Data System (ADS)

    Pearlman, Michael R.; Ipatov, Alexander; Long, James; Ma, Chopo; Merkowitz, Stephen; Neilan, Ruth; Noll, Carey; Pavlis, Erricos; Shargorodsky, Victor; Stowers, David; Wetzel, Scott

    2014-05-01

    Several initiatives are underway that should make substantial improvement over the next decade to the international space geodesy network as the international community works toward the GGOS 2020 goal of 32 globally distributed Core Sites with co-located VLBI, SLR, GNSS and DORIS. The Russian Space Agency and the Russian Academy of Sciences are moving forward with an implementation of six additional SLR systems and a number of GNSS receivers to sites outside Russia to expand GNSS tracking and support GGOS. The NASA Space Geodesy program has completed its prototype development phase and is now embarking on an implementation phase that is planning for deployment of 6 - 10 core sites in key geographic locations to support the global network. Additional sites are in the process of implementation in Europe and Asia. Site evaluation studies are in progress, looking at some new potential sites and there are ongoing discussions for partnership arrangements with interested agencies for new sites in South America and Africa. Work continues on the site layout design to avoid RF interference issues among co-located instruments and with external communications and media system. The placement of new and upgraded sites is guided by appropriate Observing System Simulation Experiments (OSSEs) conducted under the support of the interested international agencies. The results will help optimize the global distribution of core geodetic observatories and they will lead to the improvement of the data products from the future network. During this effort it is also recognized that co-located sites with less than the full core complement will continue to play an important and critical role in filling out the global network and strengthening the connection among the techniques. This talk will give an update on the current state of expansion of the global network and the projection for the network configuration that we forecast over the next 10 years.

  1. Aeronautics and space report of the President, 1983 activities

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Achievements in communication; space science; space transportation; aeronautics; and Earth resources and environment are summarized. Activities of the various Federal agencies and cooperation with NASA in these areas are described. The Presidential policy announcement on the endorsement of commercial operation of expendable launch vehicles is included. Tables show, the space activities budget; a historical budget summary, U.S. space launch vehicles; U.S. and Soviet manned spaceflights, 1961 to 1983; U.S. launched space probes, 1975 to 1983; U.S. launched scientific and applications satellites, 1978 to 1983; the U.S. spacecraft record; the world record of space launches successful in attaining Earth orbit or beyond; and successful U.S. launchings for 1983.

  2. Vehicle Engineering Development Activities at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Fisher, Mark F.; Champion, Robert H., Jr.

    1999-01-01

    New initiatives in the Space Transportation Directorate at the Marshall Space Flight Center include an emphasis on Vehicle Engineering to enhance the strong commitment to the Directorate's projects in the development of flight hardware and flight demonstrators for the advancement of space transportation technology. This emphasis can be seen in the activities of a newly formed organization in the Transportation Directorate, The Vehicle Subsystems Engineering Group. The functions and type of activities that this group works on are described. The current projects of this group are outlined including a brief description of the status and type of work that the group is performing. A summary section is included to describe future activities.

  3. Marshall Space Flight Center ECLSS technology activities

    NASA Technical Reports Server (NTRS)

    Wieland, Paul

    1990-01-01

    Viewgraphs on Environmental Control and Life Support System (ECLSS) technology activities are presented. Topics covered include: analytical development; ECLSS modeling approach; example of water reclamation modeling needs; and hardware development and testing.

  4. Reorganization of the FSU space program and its influence on worldwide space activities

    NASA Astrophysics Data System (ADS)

    Tarasenko, Maksim V.

    1993-10-01

    The paper examines changes in the organization of the former Soviet space program, current program status, and priorities, and analyzes the impact of these changes on world space activities. It is shown that after the breakup of the USSR Russia took over general responsibility for Soviet space activity. Space program management is being reorganized to split military and civil activities and to introduce a system of checks and balances. Attempts are being made to diversify the use of military space systems for civil application, including global environmental problems. Economic problems in the former Soviet republics and political tensions between them force them to search for the cooperation with the West. With a balanced Western response this trend could provide long-term mutual benefits.

  5. A simulation system for Space Station extravehicular activity

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose A.; Shepherd, Chip

    1993-01-01

    America's next major step into space will be the construction of a permanently manned Space Station which is currently under development and scheduled for full operation in the mid-1990's. Most of the construction of the Space Station will be performed over several flights by suited crew members during an extravehicular activity (EVA) from the Space Shuttle. Once fully operational, EVA's will be performed from the Space Station on a routine basis to provide, among other services, maintenance and repair operations of satellites currently in Earth orbit. Both voice recognition and helmet-mounted display technologies can improve the productivity of workers in space by potentially reducing the time, risk, and cost involved in performing EVA. NASA has recognized this potential and is currently developing a voice-controlled information system for Space Station EVA. Two bench-model helmet-mounted displays and an EVA simulation program have been developed to demonstrate the functionality and practicality of the system.

  6. Updates on CCMC Activities and GSFC Space Weather Services

    NASA Technical Reports Server (NTRS)

    Zhengm Y.; Hesse, M.; Kuznetsova, M.; Pulkkinen, A.; Rastaetter, L.; Maddox, M.; Taktakishvili, A.; Berrios, D.; Chulaki, A.; Lee, H.; Macneice, P.; Mays, L.; Mendoza, A. M.; Mullinix, R.

    2011-01-01

    In this presentation, we provide updates on CCMC modeling activities, CCMC metrics and validation studies, and other CCMC efforts. In addition, an overview of GSFC Space Weather Services (a sibling organization to the Community Coordinated Modeling Center) and its products/capabilities will be given. We show how some of the research grade models, if running in an operational mode, can help address NASA's space weather needs by providing forecasting/now casting capabilities of significant space weather events throughout the solar system.

  7. Weather support activities for the Space Shuttle

    NASA Astrophysics Data System (ADS)

    Rigdon, Gerald G.

    The work of the Spaceflight Meteorology Group (SMG) at the Mission Control Center (MCC) at the Johnson Space Center (JSC) is discussed. The primary function of the SMG is to provide operational meteorological support to the MCC. SMG meteorologists have the final responsibility for all weather forecasts and meteorological advice used by the MCC. This responsibility includes mission planning, launch-abort-site decisions (which could delay a launch), emergency landing prior to the normal end of mission, and the normal end-of-mission forecast. Another SMG function is computer system management, which involves the node management of the JSC Meteorological Interactive Data Display system. Weather flight rules, mission planning and training support, on-orbit and end-of-mission support, and equipment and data sources are also discussed.

  8. Expanding the Scope of 2′-SCF3 Modified RNA

    PubMed Central

    Jud, Lukas; Košutić, Marija; Schwarz, Veronika; Hartl, Markus; Kreutz, Christoph; Bister, Klaus; Micura, Ronald

    2015-01-01

    The 2′-trifluoromethylthio (2′-SCF3) modification endows ribonucleic acids with exceptional properties and has attracted considerable interest as a reporter group for NMR spectroscopic applications. However, only modified pyrimidine nucleosides have been generated so far. Here, the syntheses of 2′-SCF3 adenosine and guanosine phosphoramidites of which the latter was obtained in highly efficient manner by an unconventional Boc-protecting group strategy, are reported. RNA solid-phase synthesis provided site-specifically 2′-SCF3-modified oligoribonucleotides that were investigated intensively. Their excellent behavior in 19F NMR spectroscopic probing of RNA ligand binding was exemplified for a noncovalent small molecule–RNA interaction. Moreover, comparably to the 2′-SCF3 pyrimidine nucleosides, the purine counterparts were also found to cause a significant thermodynamic destabilization when located in double helical regions. This property was considered beneficial for siRNA design under the aspect to minimize off-target effects and their performance in silencing of the BASP1 gene was demonstrated. PMID:26074479

  9. CFD Modeling Activities at the NASA Stennis Space Center

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel

    2007-01-01

    A viewgraph presentation on NASA Stennis Space Center's Computational Fluid Dynamics (CFD) Modeling activities is shown. The topics include: 1) Overview of NASA Stennis Space Center; 2) Role of Computational Modeling at NASA-SSC; 3) Computational Modeling Tools and Resources; and 4) CFD Modeling Applications.

  10. Distributed active control of large flexible space structures

    NASA Technical Reports Server (NTRS)

    Nguyen, C. C.; Baz, A.

    1986-01-01

    This progress report summarizes the research work performed at the Catholic University of America on the research grant entitled Distributed Active Control of Large Flexible Space Structures, funded by NASA/Goddard Space Flight Center, under grant number NAG5-749, during the period of March 15, 1986 to September 15, 1986.

  11. Space-Based Astronomy: A Teacher's Guide with Activities.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This curriculum guide uses hands-on activities to help grade 5-8 students and teachers understand the significance of space-based astronomy--astronomical observations made from outside the Earth's atmosphere. The guide begins with a survey of astronomy-related spacecraft that the National Aeronautics and Space Administration (NASA) has sent into…

  12. SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling - potential applications as a homing factor in dental pulp regeneration.

    PubMed

    Pan, Shuang; Dangaria, Smit; Gopinathan, Gokul; Yan, Xiulin; Lu, Xuanyu; Kolokythas, Antonia; Niu, Yumei; Luan, Xianghong

    2013-10-01

    Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100 nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 h culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 min after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling. PMID:23703692

  13. ISODEX: An entry point for developing countries into space activities

    NASA Astrophysics Data System (ADS)

    Skinner, Mark Andrew

    2015-08-01

    Several threads current in the community of international space actors have led to calls at UN COPUOS Scientific & Technical Sub-Committee meetings for enhancing the scientific information available on man-made space objects, whilst fostering international space object data sharing. Growing awareness of the problems of space debris proliferation and space traffic management, especially amongst developing countries and non-traditional space faring nations, have fueled their desires to become involved in the areas of space object tracking, utilizing relatively modest astronomical instrumentation. Additionally, several commercial satellite operators, members of the Satellite Data Association, have called for augmentation of the information available from existing catalogs. This confluence of factors has led to an international discussion, at the UN and elsewhere, of the possibility of creating a clearing-house for parties willing to share data on space objects, with a working title of the “International Space Object Data Exchange” (ISODEX). We discuss the ideas behind this concept, how it might be implemented, and it might enhance the public’s knowledge of space activities, as well as providing an entry point into space for developing countries.

  14. Trajectory data analyses for pedestrian space-time activity study.

    PubMed

    Qi, Feng; Du, Fei

    2013-01-01

    It is well recognized that human movement in the spatial and temporal dimensions has direct influence on disease transmission(1-3). An infectious disease typically spreads via contact between infected and susceptible individuals in their overlapped activity spaces. Therefore, daily mobility-activity information can be used as an indicator to measure exposures to risk factors of infection. However, a major difficulty and thus the reason for paucity of studies of infectious disease transmission at the micro scale arise from the lack of detailed individual mobility data. Previously in transportation and tourism research detailed space-time activity data often relied on the time-space diary technique, which requires subjects to actively record their activities in time and space. This is highly demanding for the participants and collaboration from the participants greatly affects the quality of data(4). Modern technologies such as GPS and mobile communications have made possible the automatic collection of trajectory data. The data collected, however, is not ideal for modeling human space-time activities, limited by the accuracies of existing devices. There is also no readily available tool for efficient processing of the data for human behavior study. We present here a suite of methods and an integrated ArcGIS desktop-based visual interface for the pre-processing and spatiotemporal analyses of trajectory data. We provide examples of how such processing may be used to model human space-time activities, especially with error-rich pedestrian trajectory data, that could be useful in public health studies such as infectious disease transmission modeling. The procedure presented includes pre-processing, trajectory segmentation, activity space characterization, density estimation and visualization, and a few other exploratory analysis methods. Pre-processing is the cleaning of noisy raw trajectory data. We introduce an interactive visual pre-processing interface as well as an

  15. The valence-bond self-consistent field method (VB-SCF): Theory and test calculations

    NASA Astrophysics Data System (ADS)

    van Lenthe, J. H.; Balint-Kurti, G. G.

    1983-05-01

    A new and very general form of valence-bond theory is described. In this theory the molecular wave function is written as any desired linear combination of valence-bond structures, and the nonorthogonal orbitals used in the construction of the valence-bond structures are allowed to distort to their optimal shapes. The orbital optimization is achieved through successive transformations of an orbital basis. The theory of the method is based on an extension of the ``generalized Brillouin theorem'' which is presented in the text. The new VB-SCF method is a generalization of the molecular orbital MC-SCF method to permit the use of nonorthogonal orbitals. It, therefore, encompasses the MC-SCF method as a restricted subclass. Several different forms of restriction may be imposed on the orbitals and on the optimization procedures. One of these only allows orbitals centered on the same atom to mix during optimization and in this way generates optimal hybrid orbitals, which it is expected will prove to be of particular interest in providing simple qualitative descriptions of the chemical bond. Test calculations are presented for LiH, He+2, and for the ground-state potential energy curve of OH. The VB-SCF wave function and optimized orbitals may be used as a starting point for the construction of a larger multistructure valence-bond wave function which we term a VB-CI function. The VB-SCF and VB-CI results presented in the paper show that the method is capable of yielding very accurate molecular potential energy curves.

  16. Space activities of the United Nations and international organizations

    SciTech Connect

    Not Available

    1986-01-01

    Covering the period up to mid-1985, this work provides an overview of the organizational structure, past activities, current programs, and future plans of international bodies involved in cooperative efforts in the peaceful uses of outer space. It describes the efforts of the United Nations and several of its specialized agencies, including FAO, UNESCO, the International Civil Aviation Organization, the World Meteorological Organization, and the International Telecommunication Union. Other intergovernmental organizations covered include the European Space Agency, the International Organization of Space Communications, and the Council on International Cooperation in the Study and Utilization of Space. Nongovernmental organizations discussed are the International Council of Scientific Unions and the International Astronautical Union.

  17. Defining filled and empty space: reassessing the filled space illusion for active touch and vision.

    PubMed

    Collier, Elizabeth S; Lawson, Rebecca

    2016-09-01

    In the filled space illusion, an extent filled with gratings is estimated as longer than an equivalent extent that is apparently empty. However, researchers do not seem to have carefully considered the terms filled and empty when describing this illusion. Specifically, for active touch, smooth, solid surfaces have typically been used to represent empty space. Thus, it is not known whether comparing gratings to truly empty space (air) during active exploration by touch elicits the same illusionary effect. In Experiments 1 and 2, gratings were estimated as longer if they were compared to smooth, solid surfaces rather than being compared to truly empty space. Consistent with this, Experiment 3 showed that empty space was perceived as longer than solid surfaces when the two were compared directly. Together these results are consistent with the hypothesis that, for touch, the standard filled space illusion only occurs if gratings are compared to smooth, solid surfaces and that it may reverse if gratings are compared to empty space. Finally, Experiment 4 showed that gratings were estimated as longer than both solid and empty extents in vision, so the direction of the filled space illusion in vision was not affected by the nature of the comparator. These results are discussed in relation to the dual nature of active touch. PMID:27233286

  18. Brain in Space: A Teacher's Guide with Activities for Neuroscience

    NASA Technical Reports Server (NTRS)

    Sullivan, Walter W., Jr.

    1998-01-01

    The lessons and activities in this guide will engage your students in the excitement of space life science investigations after the Neurolab Spacelab mission. It is the authors' goal that the information in this guide will inspire both you and your students to become interested and active participants in this space mission. Few experiences can compare with the excitement and thrill of watching a Shuttle launch. This guide provides an opportunity for you and your students to go one step further by conducting the experiments on Earth that are relevent to the research conducted in space.

  19. Active optics for space applications: an ESA perspective

    NASA Astrophysics Data System (ADS)

    Zuccaro Marchi, Alessandro; Hallibert, Pascal; Pereira do Carmo, Joao; Wille, Eric

    2014-07-01

    Active optics for Space is relatively new field that takes advantage of lessons learnt on ground, and together with the tighter constrains of space environment it allows operation of larger mirrors apertures for space telescopes and better image quality. Technical developments are crucial to guarantee proper technological readiness for applications on new missions whose performance can be driven also by these novelties. This paper describes the philosophy pursued at ESA, providing an overview of the activities run within the Agency, as well as perspectives for new developments. The Optics Section of the Directorate of Technical and Quality Management of ESA/ESTEC is currently running three projects. Two examples are here addressed.

  20. Large Active Retrodirective Arrays for Space Applications

    NASA Technical Reports Server (NTRS)

    Chernoff, R. C.

    1978-01-01

    An active retrodirective array (ARA) electronically points a microwave beam back at the apparent source of an incident pilot signal. Retrodirectivity is the result of phase conjugation of the pilot signal received by each element of the array. The problem of supplying the correct phase reference to the phase conjugation circuit (PCC) associated with each element of the array is solved by central phasing. By eliminating the need for structural rigidity, central phasing confers a decisive advantage on ARA's as large spaceborne antennas. A new form of central phasing suitable for very large arrays is described. ARA's may easily be modified to serve both as transmitting and receiving arrays simultaneously. Two new kinds of exact, frequency translating PCC's are described. Such PCC's provide the ARA with input-output isolation and freedom from squint. The pointing errors caused by the radial and transverse components of the ARA's velocity, by the propagation medium, and by multipath are discussed. A two element ARA breadboard was built and tested at JPL. Its performance is limited primarily by multipath induced errors.

  1. Space activities and radiation protection of crew members

    NASA Astrophysics Data System (ADS)

    Straube, Ulrich; Berger, Thomas; Reitz, Guenther; Facius, Rainer; Reiter, Thomas; Kehl, Marcel; Damann, M. D. Volker; Tognini, Michel

    Personnel working as crew in space-based activities e.g. professional astronauts and cosmo-nauts but also -to a certain extend-space flight participants ("space tourists"), demand health and safety considerations that have to include radiation protection measures. The radiation environment that a crew is exposed to during a space flight, differs significantly to that found on earth including commercial aviation, mainly due to the presence of heavy charged particles with great potential for biological damage. The exposure exceeds those routinely received by terrestrial radiation workers. A sequence of activities has to be conducted targeting to mitigate adverse effects of space radiation. Considerable information is available and applied through the joint efforts of the Space Agencies that are involved in the operations of the International Space Station, ISS. This presentation will give an introduction to the current measures for ra-diation monitoring and protection of astronauts of the European Space Agency (ESA). It will include information: on the radiation protection guidelines that shall ensure the proper imple-mentation and execution of radiation protection measures, the operational hardware used for radiation monitoring and personal dosimetry on ISS, as well as information about operational procedures that are applied.

  2. Perspectives from space: NASA classroom information and activities

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This booklet contains the information and classroom activities included on the backs of the eight poster series, 'Perspectives From Space'. The first series, Earth, An Integrated System, contains information on global ecology, remote sensing from space, data products, earth modeling, and international environmental treaties. The second series, Patterns Among Planets, contains information on the solar system, planetary processes, impacts and atmospheres, and a classroom activity on Jupiter's satellite system. The third series, Our Place In The Cosmos, contains information on the scale of the universe, origins of the universe, mission to the universe, and three classroom activities. The fourth series, Our Sun, The Nearest Star, contains information on the Sun. The fifth series, Oasis Of Life, contains information on the development of life, chemical and biological evolution on Earth and the search for other life in the universe. The sixth series, The Influence Of Gravity, contains information on Newton's Law of Gravity, space and microgravity, microgravity environment, and classroom activities on gravity. The seventh series, The Spirit Of Exploration, contains information on space exploration, the Apollo Program, future exploration activities, and two classroom activities. The eighth series, Global Cooperation, contains information on rocketry, the space race, and multi-nation exploration projects.

  3. Development of magnetostrictive active members for control of space structures

    NASA Technical Reports Server (NTRS)

    Johnson, Bruce G.; Avakian, Kevin M.; Fenn, Ralph C.; Gaffney, Monique S.; Gerver, Michael J.; Hawkey, Timothy J.; Boudreau, Donald J.

    1992-01-01

    The goal of this Phase 2 Small Business Innovative Research (SBIR) project was to determine the technical feasibility of developing magnetostrictive active members for use as truss elements in space structures. Active members control elastic vibrations of truss-based space structures and integrate the functions of truss structure element, actively controlled actuator, and sensor. The active members must control structural motion to the sub-micron level and, for many proposed space applications, work at cryogenic temperatures. Under this program both room temperature and cryogenic temperature magnetostrictive active members were designed, fabricated, and tested. The results of these performance tests indicated that room temperature magnetostrictive actuators feature higher strain, stiffness, and force capability with lower amplifier requirements than similarly sized piezoelectric or electrostrictive active members, at the cost of higher mass. Two different cryogenic temperature magnetostrictive materials were tested at liquid nitrogen temperatures, both with larger strain capability than the room temperature magnetostrictive materials. The cryogenic active member development included the design and fabrication of a cryostat that allows operation of the cryogenic active member in a space structure testbed.

  4. Assessing Built Environment Walkability using Activity-Space Summary Measures

    PubMed Central

    Tribby, Calvin P.; Miller, Harvey J.; Brown, Barbara B.; Werner, Carol M.; Smith, Ken R.

    2015-01-01

    There is increasing emphasis on active transportation, such as walking, in transportation planning as a sustainable form of mobility and in public health as a means of achieving recommended physical activity and better health outcomes. A research focus is the influence of the built environment on walking, with the ultimate goal of identifying environmental modifications that invite more walking. However, assessments of the built environment for walkability are typically at a spatially disaggregate level (such as street blocks) or at a spatially aggregate level (such as census block groups). A key issue is determining the spatial units for walkability measures so that they reflect potential walking behavior. This paper develops methods for assessing walkability within individual activity spaces: the geographic region accessible to an individual during a given walking trip. We first estimate street network-based activity spaces using the shortest path between known trip starting/ending points and a travel time budget that reflects potential alternative paths. Based on objective walkability measures of the street blocks, we use three summary measures for walkability within activity spaces: i) the average walkability score across block segments (representing the general level of walkability in the activity space); ii) the standard deviation (representing the walkability variation), and; iii) the network autocorrelation (representing the spatial coherence of the walkability pattern). We assess the method using data from an empirical study of built environment walkability and walking behavior in Salt Lake City, Utah, USA. We visualize and map these activity space summary measures to compare walkability among individuals’ trips within their neighborhoods. We also compare summary measures for activity spaces versus census block groups, with the result that they agree less than half of the time. PMID:27213027

  5. Present Research and Standardization Activities on Small Space Debris at Space Environment Prevention

    NASA Astrophysics Data System (ADS)

    Kitazawa, Yukihito; Hanada, Toshiya; Matsumoto, Haruhisa; Akahoshi, Yasuhiro; Higashide, Masumi; Okudaira, Osamu; Kamiya, Koki; Nitta, Kumi

    2016-07-01

    The micro-debris of the size from 100 μm to several mm is expected to cause a spacecraft critical failures and troubles. However, the collision probability of the micro-debris and its effect on space equipment are hardly predicted due to lack knowledge regarding the debris distribution and experimental/numerical investigation on material and components. This paper introduce research and standardization activities related on micro-debris for space environmental prevention

  6. Aeronautics and space report of the President, 1980 activities

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The year's achievements in the areas of communication, Earth resources, environment, space sciences, transportation, and space energy are summarized and current and planned activities in these areas at the various departments and agencies of the Federal Government are summarized. Tables show U.S. and world spacecraft records, spacecraft launchings for 1980, and scientific payload anf probes launched 1975-1980. Budget data are included.

  7. Space Weather Monitoring and Forecasting Activity in NICT

    NASA Astrophysics Data System (ADS)

    Nagatsuma, Tsutomu; Watari, Shinichi; T. Murata, Ken

    Disturbances of Space environment around the Earth (geospace) is controlled by the activity of the Sun and the solar wind. Disturbances in geospace sometimes cause serious problems to satellites, astronauts, and telecommunications. To minimize the effect of the problems, space weather forecasting is necessary. In Japan, NICT (National Institute of Information and Communications Technology) is in charge of space weather forecasting services as a regional warning center of International Space Environment Service. With help of geospace environment data exchanging among the international cooperation, NICT operates daily space weather forecast service every day to provide information on nowcasts and forecasts of solar flare, geomagnetic disturbances, solar proton event, and radio-wave propagation conditions in the ionosphere. For prompt reporting of space weather information, we also conduct our original observation networks from the Sun to the upper atmosphere: Hiraiso solar observatory, domestic ionosonde networks, magnetometer & HF radar observations in far-east Siberia and Alaska, and south-east Asia low-latitude ionospheric network (SEALION). ACE (Advanced Composition Explorer) and STEREO (Solar TErrestrial RElations Observatory) real-time beacon data are received using our antenna facilities to monitor the solar and solar wind conditions in near real-time. Our current activities and future perspective of space weather monitoring and forecasting will be introduced in this report.

  8. Determination Of The Activity Space By The Stereometric Method

    NASA Astrophysics Data System (ADS)

    Deloison, Y.; Crete, N.; Mollard, R.

    1980-07-01

    To determine the activity space of a sitting subject, it is necessary to go beyond the mere statistical description of morphology and the knowledge of the displacement volume. An anlysis of the positions or variations of the positions of the diverse segmental elements (arms, hands, lower limbs, etc...) in the course of a given activity is required. Of the various methods used to locate quickly and accurately the spatial positions of anatomical points, stereometry makes it possible to plot the three-dimensional coordinates of any point in space in relation to a fixed trirectangle frame of reference determined by the stereome-tric measuring device. Thus, regardless of the orientation and posture of the subject, his segmental elements can be easily pin-pointed, throughout the experiment, within the space they occupy. Using this method, it is possible for a sample of operators seated at an operation station and applying either manual controls or pedals and belonging to a population statistically defined from the data collected and the analyses produced by the anthropometric study to determine a contour line of reach capability marking out the usable working space and to know, within this working space, a contour line of preferential activity that is limited, in space, by the whole range of optimal reach capability of all the subjects.

  9. Activities on Space Debris in U.S.

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2001-01-01

    In the U.S. space debris activities are addressed at all government levels, from the Executive Office of the President to the individual federal agencies to specialized centers, laboratories, organizations, and research groups. U.S. Space Policy specifically challenges government agencies to seek to minimize the creation of space debris and to promote debris minimization practices both domestically and internationally. A set of space debris mitigation standard practices has been developed and adopted by relevant US government agencies, and their application by the commercial aerospace community is highly encouraged. A growing number of US government agencies have issued their own space debris mitigation policies, directives, regulations, and standards. Space debris research, including the definition and modeling of the current and future near-Earth space environment and the development of debris protection technologies, is principally conducted by NASA and the Department of Defense. The U.S. Space Surveillance Network continues to provide the most complete and timely characterization of the population of space debris larger than 10 cm. During the past several years major advancements have been achieved in extending this environment definition in LEO to include particles as small as only a few millimeters. The inspection of returned spacecraft surfaces continues to shed light on the even smaller debris population. With improvements in computer technology, new and more capable programs have been and are being developed to solve a number of operational and research problems. Finally, the academic and industrial sectors of the U.S. are also increasing their participation in and contributions to space debris operations and research. The cooperation of satellite and launch vehicle developers and operators is essential to the U.S. objective of promoting the preservation of the space environment for future generations.

  10. Activities on space debris in U.S.

    NASA Astrophysics Data System (ADS)

    Johnson, Nicholas L.

    2001-10-01

    In the U.S. space debris activities are addressed at all government levels, from the Executive Office of the President to the individual federal agencies to specialized centers, laboratories, organizations, and research groups. U.S. Space Policy specifically challenges government agencies to seek to minimize the creation of space debris and to promote debris minimization practices, both domestically and internationally. A set of space debris mitigation standard practices has been developed and adopted by relevant U.S. government agencies, and their application by the commercial aerospace community is highly encouraged. A growing number of U.S. government agencies have issued their own space debris mitigation policies, directives, regulations, and standards. Space debris research, including the definition and modeling of the current and future near-Earth space environment and the development of debris protection technologies, is principally conducted by NASA and the Department of Defense. The U.S. Space Surveillance Network continues to provide the most complete and timely characterization of the population of space debris larger than 10 cm. During the past several years major advancements have been achieved in extending this environment definition in LEO to include particles as small as only a few millimeters. The inspection of returned spacecraft surfaces continues to shed light on the even smaller debris population. With improvements in computer technology, new and more capable programs have been and are being developed to solve a number of operational and research problems. Finally, the academic and industrial sectors of the U.S. are also increasing their participation in and contributions to space debris operations and research. The cooperation of spacecraft and launch vehicle developers and operators is essential to the U.S. objective of promoting the preservation of the space environment for future generations.

  11. Changes in gastric myoelectric activity during space flight

    NASA Technical Reports Server (NTRS)

    Harm, Deborah L.; Sandoz, Gwenn R.; Stern, Robert M.

    2002-01-01

    The purpose of the present study was to examine postprandial myoelectric activity of the stomach and gastric activity associated with space motion sickness using electrogastrography. Three crewmembers participated in this investigation. Preflight, subjects exhibited normal postprandial responses to the ingestion of a meal. Inflight, crewmembers exhibited an abnormal decrease in the power of the normal gastric slow wave after eating on flight day 1, but had a normal postprandial response by flight day 3. Prior to and during episodes of nausea and vomiting, the electrical activity of the stomach became dysrhythmic with 60-80% of the spectral power in the bradygastric and tachygastric frequency ranges. These findings indicate that gastric motility may be decreased during the first few days of space flight. In addition, changes in the frequency of the gastric slow wave associated with space motion sickness symptoms are consistent with those reported for laboratory-induced motion sickness.

  12. Neuromuscular activation patterns during treadmill walking after space flight

    NASA Technical Reports Server (NTRS)

    Layne, C. S.; McDonald, P. V.; Bloomberg, J. J.

    1997-01-01

    Astronauts adopt a variety of neuromuscular control strategies during space flight that are appropriate for locomoting in that unique environment, but are less than optimal upon return to Earth. We report here the first systematic investigation of potential adaptations in neuromuscular activity patterns associated with postflight locomotion. Astronaut-subjects were tasked with walking on a treadmill at 6.4 km/h while fixating a visual target 30 cm away from their eyes after space flights of 8-15 days. Surface electromyography was collected from selected lower limb muscles and normalized with regard to mean amplitude and temporal relation to heel strike. In general, high correlations (more than 0.80) were found between preflight and postflight activation waveforms for each muscle and each subject: however relative activation amplitude around heel strike and toe off was changed as a result of flight. The level of muscle cocontraction and activation variability, and the relationship between the phasic characteristics of the ankle musculature in preparation for toe off also were altered by space flight. Subjects also reported oscillopsia during treadmill walking after flight. These findings indicate that, after space flight, the sensory-motor system can generate neuromuscular-activation strategies that permit treadmill walking, but subtle changes in lower-limb neuromuscular activation are present that may contribute to increased lower limb kinematic variability and oscillopsia also present during postflight walking.

  13. Aeronautics and Space Report of the President: Fiscal Year 1996 Activities

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Topics considered include: (1) Space launch activities: space shuttle missions; expendable launch vehicles. (2) Space science: astronomy and space physics; solar system exploration. (3) Space flight and technology: life and microgravity sciences; space shuttle technology; reuseable launch vehicles; international space station; energy; safety and mission assurance; commercial development and regulation of space; surveillance. (4) Space communications: communications satellites; space network; ground networks; mission control and data systems. (5) Aeronautical activities: technology developments; air traffic control and navigation; weather-related aeronautical activities; flight safety and security; aviation medicine and human factors. (6) Studies of the planet earth: terrestrial studies and applications: atmospheric studies: oceanographic studies; international aeronautical and space activities; and appendices.

  14. Ionic conductivity of ScF3 single crystals (ReO3 type)

    NASA Astrophysics Data System (ADS)

    Sorokin, N. I.; Karimov, D. N.; Grebenev, V. V.; Sobolev, B. P.

    2016-03-01

    Electrical conductivity σ of ScF3 single crystals (sp. gr. Pmoverline 3 m, ReO3 structure type) has been studied by impedance spectroscopy and compared with the electrical conductivity of rare earth HoF3 (β-YF3 type) and LaF3 (tysonite type) trifluorides. ScF3 crystals obtained by Bridgman directional solidification have ionic conductivity σ = 4 × 10-8 S/cm at 673 K. It is smaller than the σ values for LaF3 (sp. gr. Poverline 3 c1) and HoF3 (sp. gr. Pnma) single crystals by a factor of 104-105. The low conductivity of ScF3 crystals is due to the weak coordinating ability (coordination number CN = 6) and low electronic polarizability (α cat = 1.1 Å3) of Sc3+ ions. Mobile V F + vacancies and less mobile interstitial V i - ions (defects are formed according to the Frenkel mechanism) are involved in the ion transport. HoF3 and LaF3 single crystals have a high coordinating ability (CN = 9 for Ho3+ and CN = 11 for La3+) and a high electronic polarizability of cations (α cat = 1.6-1.9 Å3 for Ho3+ and α cat = 2.2 Å3 for La3+). Only mobile V F + vacancies (defects are formed according to the Schottky mechanism) are involved in ion transport.

  15. Multiplicity, instability, and SCF convergence problems in Hartree-Fock solutions

    SciTech Connect

    Dardenne, L.E.; Makiuchi, N.; Malbouisson, L.A.C.; Vianna, J.D.M.

    2000-02-15

    The authors present a study of the instability and convergence of Hartree-Fock (HF) ab initio solutions for the diatomic systems H{sub 2}, LiH, CH, C{sub 2}, and N{sub 2}. In the study, they consider real molecular orbitals (MOs) and analyze the classes of single-determinant functions associated to Hartree-Fock-Roothaan (HFR) and Hartree-Fock-Pople-Nesbet (HFPN) equations. To determine the multiple HF solutions, they used either an SCF iterative procedure with aufbau and non-aufbau ordering rules or the algebraic method (AM). Stability conditions were determined using TICS and ASDW stability matrices, derived from the maximum and minimum method of functions (MMF). They examined the relationship between pure SCF convergence criterion with the aufbau ordering rule, and the classification of the HF solution as an extremum point in its respective class of functions. The results show that (1) in a pure converged SCF calculation, with the aufbau ordering rule, the solutions are not necessarily classified as a minimum of the HF functional with respect to the TICS or ASDW classes of solutions, and (2) for all studied systems, they obtained local minimum points associated only with the aufbau rule and the solutions of lower energies.

  16. The Ubiquitin Ligase SCF(Ucc1) Acts as a Metabolic Switch for the Glyoxylate Cycle.

    PubMed

    Nakatsukasa, Kunio; Nishimura, Takashi; Byrne, Stuart D; Okamoto, Michiyo; Takahashi-Nakaguchi, Azusa; Chibana, Hiroji; Okumura, Fumihiko; Kamura, Takumi

    2015-07-01

    Despite the crucial role played by the glyoxylate cycle in the virulence of pathogens, seed germination in plants, and sexual development in fungi, we still have much to learn about its regulation. Here, we show that a previously uncharacterized SCF(Ucc1) ubiquitin ligase mediates proteasomal degradation of citrate synthase in the glyoxylate cycle to maintain metabolic homeostasis in glucose-grown cells. Conversely, transcription of the F box subunit Ucc1 is downregulated in C2-compound-grown cells, which require increased metabolic flux for gluconeogenesis. Moreover, in vitro analysis demonstrates that oxaloacetate regenerated through the glyoxylate cycle induces a conformational change in citrate synthase and inhibits its recognition and ubiquitination by SCF(Ucc1), suggesting the existence of an oxaloacetate-dependent positive feedback loop that stabilizes citrate synthase. We propose that SCF(Ucc1)-mediated regulation of citrate synthase acts as a metabolic switch for the glyoxylate cycle in response to changes in carbon source, thereby ensuring metabolic versatility and flexibility. PMID:25982115

  17. IL-7 and SCF Levels Inversely Correlate with T Cell Reconstitution and Clinical Outcomes after Cord Blood Transplantation in Adults

    PubMed Central

    Politikos, Ioannis; Kim, Haesook T.; Nikiforow, Sarah; Li, Lequn; Brown, Julia; Antin, Joseph H.; Cutler, Corey; Ballen, Karen; Ritz, Jerome; Boussiotis, Vassiliki A.

    2015-01-01

    Recovery of thymopoiesis is critical for immune reconstitution after HSCT. IL-7 and SCF are two major thymotropic cytokines. We investigated whether the kinetics of circulating levels of these cytokines might provide insight into the prolonged immunodeficiency after double umbilical cord blood transplantation (dUCBT) in adults. We examined plasma levels of IL-7 and SCF, T-cell receptor rearrangement excision circle (TREC) levels and T cell subsets in 60 adult patients undergoing dUCBT. Median levels of IL-7 increased by more than 3-fold at 4 weeks and remained elevated through 100 days after dUCBT. SCF showed a less than 2-fold increase and more protracted elevation than IL-7. IL-7 levels inversely correlated with the reconstitution of various T cell subsets but not with TRECs. SCF levels inversely correlated with reconstitution of CD4+T cells, especially the naïve CD4+CD45RA+ subset, and with TRECs suggesting that SCF but not IL-7 had an effect on thymic regeneration. In Cox models, elevated levels of IL-7 and SCF were associated with higher non-relapse mortality (p = 0.03 and p = 0.01) and worse overall survival (p = 0.002 and p = 0.001). Elevated IL-7 but not SCF was also associated with development of GvHD (p = 0.03). Thus, IL-7 and SCF are elevated for a prolonged period after dUCBT and persistently high levels of these cytokines may correlate with worse clinical outcomes. PMID:26177551

  18. Waves In Space Plasmas (WISP): A space plasma lab active experiment

    NASA Technical Reports Server (NTRS)

    Fredricks, R. W.

    1983-01-01

    The Waves in Space Plasmas (WISP) series of Spacelab Space Plasma Labs devoted to active experimentation, are introduced. Space Plasma Lab-1 is keyed to active probing of the ionosphere and magnetosphere using controlled wave injections by the WISP VLF and HF transmitters, supported by a free-flying plasma diagnostics package instrumented with wave receivers and particle probe diagnostics, designed to measure radiation and propagation of plasma waves, precipitated particle fluxes due to wave/particle interactions, and similar phenomena resulting from wave injectons. The VLF transmitter delivers up to 1 kW of RF power into the antenna terminals over the range from 0.3 to 30 kHz. The HF transmitter delivers up to 500 W to the antenna over the range from 1 to 30 MHz. A dipole antenna commandable to any extension up to 300 m tip-to-tip is available.

  19. Learning Activity Models for Multiple Agents in a Smart Space

    NASA Astrophysics Data System (ADS)

    Crandall, Aaron; Cook, Diane J.

    With the introduction of more complex intelligent environment systems, the possibilities for customizing system behavior have increased dramatically. Significant headway has been made in tracking individuals through spaces using wireless devices [1, 18, 26] and in recognizing activities within the space based on video data (see chapter by Brubaker et al. and [6, 8, 23]), motion sensor data [9, 25], wearable sensors [13] or other sources of information [14, 15, 22]. However, much of the theory and most of the algorithms are designed to handle one individual in the space at a time. Resident tracking, activity recognition, event prediction, and behavior automation becomes significantly more difficult for multi-agent situations, when there are multiple residents in the environment.

  20. Collaborative Human Engineering Work in Space Exploration Extravehicular Activities (EVA)

    NASA Technical Reports Server (NTRS)

    DeSantis, Lena; Whitmore, Mihriban

    2007-01-01

    A viewgraph presentation on extravehicular activities in space exploration in collaboration with other NASA centers, industries, and universities is shown. The topics include: 1) Concept of Operations for Future EVA activities; 2) Desert Research and Technology Studies (RATS); 3) Advanced EVA Walkback Test; 4) Walkback Subjective Results; 5) Integrated Suit Test 1; 6) Portable Life Support Subsystem (PLSS); 7) Flex PLSS Design Process; and 8) EVA Information System; 9)

  1. Active vibration damping of the Space Shuttle remote manipulator system

    NASA Technical Reports Server (NTRS)

    Scott, Michael A.; Gilbert, Michael G.; Demeo, Martha E.

    1991-01-01

    The feasibility of providing active damping augmentation of the Space Shuttle Remote Manipulator System (RMS) following normal payload handling operations is investigated. The approach used in the analysis is described, and the results for both linear and nonlinear performance analysis of candidate laws are presented, demonstrating that significant improvement in the RMS dynamic response can be achieved through active control using measured RMS tip acceleration data for feedback.

  2. Draft position paper on knowledge management in space activities

    NASA Technical Reports Server (NTRS)

    Holm, Jeanne; Moura, Denis

    2003-01-01

    As other fields of industry, space activities are facing the challenge of Knowledge Management and the International Academy of Astronautics decided to settle in 2002 a Study Group to analyse the problem and issue general guidelines. This communication presents the draft position paper of this group in view to be discussed during the 2003 IAF Congress.

  3. Space Station Freedom. An Activity Book for Elementary School Students.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This booklet was prepared by the National Aeronautics and Space Administration (NASA) for use by teachers in the classroom or by parents at home. The descriptions, classroom activities and illustrations are designed for elementary-level school children. On each right-hand page is a simple line drawing that illustrates the narrative and the…

  4. Activity Spaces and Urban Adolescent Substance Use and Emotional Health

    ERIC Educational Resources Information Center

    Mason, Michael J.; Korpela, Kalevi

    2009-01-01

    This study analyzed routine locations (activity spaces) of urban adolescents enrolled in a substance abuse treatment program to understand the relationship between their spatial lives and health outcomes such as substance use and mental health. Sixty-eight adolescents were interviewed and produced a list of 199 locations identified as most…

  5. Six degree of freedom active vibration damping for space application

    NASA Technical Reports Server (NTRS)

    Haynes, Leonard S.

    1993-01-01

    Work performed during the period 1 Jan. - 31 Mar. 1993 on six degree of freedom active vibration damping for space application is presented. A performance and cost report is included. Topics covered include: actuator testing; mechanical amplifier design; and neural network control system development and experimental evaluation.

  6. Radiation Protection Studies of International Space Station Extravehicular Activity Space Suits

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A. (Editor); Shavers, Mark R. (Editor); Saganti, Premkumar B. (Editor); Miller, Jack (Editor)

    2003-01-01

    This publication describes recent investigations that evaluate radiation shielding characteristics of NASA's and the Russian Space Agency's space suits. The introduction describes the suits and presents goals of several experiments performed with them. The first chapter provides background information about the dynamic radiation environment experienced at ISS and summarized radiation health and protection requirements for activities in low Earth orbit. Supporting studies report the development and application of a computer model of the EMU space suit and the difficulty of shielding EVA crewmembers from high-energy reentrant electrons, a previously unevaluated component of the space radiation environment. Chapters 2 through 6 describe experiments that evaluate the space suits' radiation shielding characteristics. Chapter 7 describes a study of the potential radiological health impact on EVA crewmembers of two virtually unexamined environmental sources of high-energy electrons-reentrant trapped electrons and atmospheric albedo or "splash" electrons. The radiological consequences of those sources have not been evaluated previously and, under closer scrutiny. A detailed computational model of the shielding distribution provided by components of the NASA astronauts' EMU is being developed for exposure evaluation studies. The model is introduced in Chapters 8 and 9 and used in Chapter 10 to investigate how trapped particle anisotropy impacts female organ doses during EVA. Chapter 11 presents a review of issues related to estimating skin cancer risk form space radiation. The final chapter contains conclusions about the protective qualities of the suit brought to light form these studies, as well as recommendations for future operational radiation protection.

  7. Recent Activities on the Embrace Space Weather Regional Warning Center: the New Space Weather Data Center

    NASA Astrophysics Data System (ADS)

    Denardini, Clezio Marcos; Dal Lago, Alisson; Mendes, Odim; Batista, Inez S.; SantAnna, Nilson; Gatto, Rubens; Takahashi, Hisao; Costa, D. Joaquim; Banik Padua, Marcelo; Campos Velho, Haroldo

    2016-07-01

    On August 2007 the National Institute for Space Research started a task force to develop and operate a space weather program, which is known by the acronyms Embrace that stands for the Portuguese statement "Estudo e Monitoramento BRAasileiro de Clima Espacial" Program (Brazilian Space Weather Study and Monitoring program). The mission of the Embrace/INPE program is to monitor the Solar-Terrestrial environment, the magnetosphere, the upper atmosphere and the ground induced currents to prevent effects on technological and economic activities. The Embrace/INPE system monitors the physical parameters of the Sun-Earth environment, such as Active Regions (AR) in the Sun and solar radiation by using radio telescope, Coronal Mass Ejection (CME) information by satellite and ground-based cosmic ray monitoring, geomagnetic activity by the magnetometer network, and ionospheric disturbance by ionospheric sounders and using data collected by four GPS receiver network, geomagnetic activity by a magnetometer network, and provides a forecasting for Total Electronic Content (TEC) - 24 hours ahead - using a version of the SUPIM model which assimilates the two latter data using nudging approach. Most of these physical parameters are daily published on the Brazilian space weather program web portal, related to the entire network sensors available. Regarding outreach, it has being published a daily bulletin in Portuguese and English with the status of the space weather environment on the Sun, the Interplanetary Medium and close to the Earth. Since December 2011, all these activities are carried out at the Embrace Headquarter, a building located at the INPE's main campus. Recently, a comprehensive data bank and an interface layer are under commissioning to allow an easy and direct access to all the space weather data collected by Embrace through the Embrace web Portal. The information being released encompasses data from: (a) the Embrace Digisonde Network (Embrace DigiNet) that monitors

  8. Innovative Ideas for Coordinating International Space Activities: International Center for Space Medicine, International Space Authority, and other Global Youth Space Initiatives

    NASA Astrophysics Data System (ADS)

    Marshall, W.

    2002-01-01

    The Space Generation Forum SGF, at UNISPACE-III, as one of its ten formal recommendations to the United Nations in 1999, put forward the suggestion that the an international space authority should be created. Other recommendations were the establishment of an International Center for Space Medicine, creation of a global space exploration and development program, establishment of a global space (Nobel) prize, and a global space library. These projects are being further developed at the Space Generation Summit (SGS), an event at World Space Congress (WSC) which shall unite international students and young professionals to develop a youth vision and strategy for the peaceful uses of space. SGS, endorsed by the United Nations, will take place from October 11- 13th, during which the 200 delegates will discuss ongoing youth space activities, particularly those stemming from the UNISPACE-III/SGF and taken forward by the Space Generation Advisory Council. Delegates will address a variety of topics with the goal of devising new recommendations according to the theme, 'Accelerating Our Pace in Space'. The material presented here and in other technical sessions throughout WSC includes the findings of these discussions. In this paper, we present the International Space Authority idea together with recommendations on how that might be taken forward. The purpose of such an organization would be to allow: 1. Oversight and enforcement for the balanced regulation of multiple interests in space 2. Access for all peoples to the material benefits and knowledge and understanding enabled by the exploration and 3. Pooling of national and industry resources for the creation of space infrastructure, missions and enterprises for Operating principles: 1. The ISA regulatory regime would encourage commercialization and the harnessing of competitive market 2. Consistent with its charter to ensure access to all peoples, all UN member states and appropriate NGOs would 3. Close coordination with

  9. Legal regime of human activities in outer space law

    NASA Technical Reports Server (NTRS)

    Golda, Carlo

    1994-01-01

    Current developments in space activities increasingly involve the presence of humans on board spacecraft and, in the near future, on the Moon, on Mars, on board Space Stations, etc. With respect to these challenges, the political and legal issues connected to the status of astronauts are largely unclear and require a new doctrinal attention. In the same way, many legal and political questions remain open in the structure of future space crews: the need for international standards in the definition and training of astronauts, etc.; but, first of all, an international uniform legal definition of astronauts. Moreover, the legal structure for human life and operations in outer space can be a new and relevant paradigm for the definition of similar rules in all the situations and environments in which humans are involved in extreme frontiers. The present article starts from an overview on the existing legal and political definitions of 'astronauts', moving to the search of a more useful definition. This is followed by an analysis of the concrete problems created by human space activities, and the legal and political responses to them (the need for a code of conduct; the structure of the crew and the existing rules in the US and ex-USSR; the new legal theories on the argument; the definition and structure of a code of conduct; the next legal problems in fields such as privacy law, communications law, business law, criminal law, etc.).

  10. INSA Scientific Activities in the Space Astronomy Area

    NASA Astrophysics Data System (ADS)

    Pérez Martínez, Ricardo; Sánchez Portal, Miguel

    Support to astronomy operations is an important and long-lived activity within INSA. Probably the best known (and traditional) INSA activities are those related with real-time spacecraft operations: ground station maintenance and operation (ground station engineers and operators); spacecraft and payload real-time operation (spacecraft and instruments controllers); computing infrastructure maintenance (operators, analysts), and general site services. In this paper, we’ll show a different perspective, probably not so well-known, presenting some INSA recent activities at the European Space Astronomy Centre (ESAC) and NASA Madrid Deep Space Communication Complex (MDSCC) directly related to scientific operations. Basic lines of activity involved include: operations support for science operations; system and software support for real time systems; technical administration and IT support; R&D activities, radioastronomy (at MDSCC and ESAC), and scientific research projects. This paper is structured as follows: first, INSA activities in two ESA cornerstone astrophysics missions, XMM-Newton and Herschel, will be outlined. Then, our activities related to scientific infrastructure services, represented by the Virtual Observatory (VO) framework and the Science Archives development facilities, are briefly shown. Radio astronomy activities will be described afterwards, and, finally, a few research topics in which INSA scientists are involved will also be described.

  11. Crew activity and motion effects on the space station

    NASA Technical Reports Server (NTRS)

    Rochon, Brian V.; Scheer, Steven A.

    1987-01-01

    Among the significant sources of internal disturbances that must be considered in the design of space station vibration control systems are the loads induced on the structure from various crew activities. Flight experiment T013, flown on the second manned mission of Skylab, measured force and moment time histories for a range of preplanned crew motions and activities. This experiment has proved itself invaluable as a source of on-orbit crew induced loads that has allowed a space station forcing function data base to be built. This will enable forced response such as acceleration and deflections, attributable to crew activity, to be calculated. The flight experiment, resultant database and structural model pre-processor, analysis examples and areas of combined research shall be described.

  12. Benefits of advanced space suits for supporting routine extravehicular activity

    NASA Technical Reports Server (NTRS)

    Alton, L. R.; Bauer, E. H.; Patrick, J. W.

    1975-01-01

    Technology is available to produce space suits providing a quick-reaction, safe, much more mobile extravehicular activity (EVA) capability than before. Such a capability may be needed during the shuttle era because the great variety of missions and payloads complicates the development of totally automated methods of conducting operations and maintenance and resolving contingencies. Routine EVA now promises to become a cost-effective tool as less complex, serviceable, lower-cost payload designs utilizing this capability become feasible. Adoption of certain advanced space suit technologies is encouraged for reasons of economics as well as performance.

  13. Integrating Multiple Space Ground Sensors to Track Volcanic Activity

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Davies, Ashley; Doubleday, Joshua; Tran, Daniel; Jones, Samuel; Kjartansson, Einar; Thorsteinsson, Hrobjartur; Vogfjord, Kristin; Guomundsson, Magnus; Thordarson, Thor; Mandl, Daniel

    2011-01-01

    Volcanic activity can occur with little or no warning. Increasing numbers of space borne assets can enable coordinated measurements of volcanic events to enhance both scientific study and hazard response. We describe the use of space and ground measurements to target further measurements as part of a worldwide volcano monitoring system. We utilize a number of alert systems including the MODVOLC, GOESVOLC, US Air Force Weather Advisory, and Volcanic Ash Advisory Center (VAAC) alert systems. Additionally we use in-situ data from ground instrumentation at a number of volcanic sites, including Iceland.

  14. Structural active cooling applications for the Space Shuttle.

    NASA Technical Reports Server (NTRS)

    Masek, R. V.; Niblock, G. A.; Huneidi, F.

    1972-01-01

    Analytic and experimental studies have been conducted to evaluate a number of active cooling approaches to structural thermal protection for the Space Shuttle. The primary emphasis was directed toward the thermal protection system. Trade study results are presented for various heat shield material and TPS arrangements. Both metallic and reusable surface insulation (RSI) concepts were considered. Active systems heat sinks consisted of hydrogen, phase change materials, and expendable water. If consideration is given only to controlling the surface temperature, passive TPS was found to provide the most efficient system. Use of active cooling which incorporates some interior temperature control made the thermally less efficient RSI system more attractive.

  15. Space activities - A review and a look ahead

    NASA Technical Reports Server (NTRS)

    Durrani, S. H.

    1984-01-01

    The paper reviews the progress made in manned and unmanned space programs during the last 25 years and names several major accomplishments. The ingredients of success are identified as good engineering, good technology, and good management of a very complex enterprise. An argument is made that the pace of progress will be governed not by technological advances, which can be very rapid, but rather by future institutional arrangements, which are much slower to evolve. It is predicted that the most likely space activities for the next 20 years will be those relating to space commercialization, and several examples are cited. A hope is expressed that policy makers and entrepreneurs will match the spirit of adventure and risk-taking exhibited by engineers in exploring uncharted territory.

  16. Overview of Advanced Space Propulsion Activities in the Space Environmental Effects Team at MSFC

    NASA Technical Reports Server (NTRS)

    Edwards, David; Carruth, Ralph; Vaughn, Jason; Schneider, Todd; Kamenetzky, Rachel; Gray, Perry

    2000-01-01

    Exploration of our solar system, and beyond, requires spacecraft velocities beyond our current technological level. Technologies addressing this limitation are numerous. The Space Environmental Effects (SEE) Team at the Marshall Space Flight Center (MSFC) is focused on three discipline areas of advanced propulsion; Tethers, Beamed Energy, and Plasma. This presentation will give an overview of advanced propulsion related activities in the Space Environmental Effects Team at MSFC. Advancements in the application of tethers for spacecraft propulsion were made while developing the Propulsive Small Expendable Deployer System (ProSEDS). New tether materials were developed to meet the specifications of the ProSEDS mission and new techniques had to be developed to test and characterize these tethers. Plasma contactors were developed, tested and modified to meet new requirements. Follow-on activities in tether propulsion include the Air-SEDS activity. Beamed energy activities initiated with an experimental investigation to quantify the momentum transfer subsequent to high power, 5J, ablative laser interaction with materials. The next step with this experimental investigation is to quantify non-ablative photon momentum transfer. This step was started last year and will be used to characterize the efficiency of solar sail materials before and after exposure to Space Environmental Effects (SEE). Our focus with plasma, for propulsion, concentrates on optimizing energy deposition into a magnetically confined plasma and integration of measurement techniques for determining plasma parameters. Plasma confinement is accomplished with the Marshall Magnetic Mirror (M3) device. Initial energy coupling experiments will consist of injecting a 50 amp electron beam into a target plasma. Measurements of plasma temperature and density will be used to determine the effect of changes in magnetic field structure, beam current, and gas species. Experimental observations will be compared to

  17. Space station group activities habitability module study: A synopsis

    NASA Technical Reports Server (NTRS)

    Nixon, David; Glassman, Terry

    1987-01-01

    Space station habitability was studied by investigating crew activity routines, proximities, ergonomic envelopes, and group volumes. Ten alternative schematic interior designs were proposed. Preliminary conclusions include: (1) in-service interior modifications may be necessary and should be planned for; (2) design complexity will be increased if the module cluster is reduced from five to three; (3) the increased crew circulation attendant upon enhancement of space station activity may produce human traffic bottlenecks and should be planned for; (4) a single- or two-person quiet area may be desirable to provide crew members with needed solitude during waking hours; and (5) the decision to choose a two-shift or three-shift daily cycle will have a significant impact on the design configuration and operational efficiency of the human habitat.

  18. Legal considerations and cooperative opportunities for space commercial activities

    NASA Technical Reports Server (NTRS)

    Hosenball, S. N.

    1984-01-01

    It is a national policy to make the capabilities of the Space Transportation System available to a wide range of potential users. This includes its availability as a space manufacturing facility for commercial activities, which may be carried out on a reimbursable basis or as a joint endeavor with NASA, but with substantial private investment. In any high risk, long lead-time research and development activity directed towards commercialization, the protection afforded the results of the research and development under the laws relating to intellectual property rights may provide an important incentive for private investment. The policies and practices of NASA directed towards the protection of privately-established intellectual property rights involved in STS use are reviewed with particular emphasis on reimbursable launch agreements and joint endeavor agreements.

  19. Corrosion Activities at the NASA Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Heidersbach, Robert H.

    2002-01-01

    This report documents summer faculty fellow efforts in the corrosion test bed at the NASA Kennedy Space Center. During the summer of 2002 efforts were concentrated on three activities: a short course on corrosion control for KSC personnel, evaluation of commercial wash additives used for corrosion control on Army aircraft, and improvements in the testing of a new cathodic protection system under development at KSC.

  20. A 12 years brazilian space education activity experience

    NASA Astrophysics Data System (ADS)

    Stancato, Fernando; Gustavo Catalani Racca, João; Ballarotti, MaurícioG.

    2001-03-01

    A multidisciplinary group of students from the university and latter also from the high school was formed in 1988 with the objective to make them put in practice their knowledge in physics, chemistry and mathematics and engineering fields in experimental rocketry. The group was called "Grupo de Foguetes Experimentais", GFE. Since that time more than 150 students passed throw the group and now many of them are in the space arena. The benefits for students in a space hands-on project are many: More interest in their school subjects is gotten as they see an application for them; Interrelation attitudes are learned as space projects is a team activity; Responsibility is gained as each is responsible for a part of a critical mission project; Multidisciplinary and international experience is gotten as these are space project characteristics; Learn how to work in a high stress environment as use to be a project launch. This paper will cover the educational experiences gotten during these years and how some structured groups work. It is explained the objectives and how the group was formed. The group structure and the different phases that at each year the new team passes are described. It is shown the different activities that the group uses to do from scientific seminars, scientific club and international meetings to technical tours and assistance to rocket activities in regional schools. It is also explained the group outreach activities as some launches were covered by the media in more then 6 articles in newspaper and 7 television news. In 1999 as formed an official group called NATA, Núcleo de Atividades Aerospaciais within the Universidade Estadual de Londrina, UEL, by some GFE members and teachers from university. It is explained the first group project results.

  1. Active vibration control techniques for flexible space structures

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Jayasuriya, Suhada

    1990-01-01

    Two proposed control system design techniques for active vibration control in flexible space structures are detailed. Control issues relevant only to flexible-body dynamics are addressed, whereas no attempt was made to integrate the flexible and rigid-body spacecraft dynamics. Both of the proposed approaches revealed encouraging results; however, further investigation of the interaction of the flexible and rigid-body dynamics is warranted.

  2. Quasi-relativistic SCF X. cap alpha. study of octahedral 5f/sup 1/ complexes

    SciTech Connect

    Thornton, G.; Roesch, N.; Edelstein, N.

    1980-05-01

    Quasi-relativistic SCF X..cap alpha.. calculations have been carried out for the octahedral 5f/sup 1/ complexes Pa/sup IV/X/sub 6//sup 2 -/, U/sup V/X/sub 6//sup -/(X = F, Cl, Br, I), and Np/sup VI/F/sub 6/. The 5f ..-->.. 5f excitation energies calculated by using the transition-state method agree well with the available absorption spectra. Ionic effects appear to dominate the trends observed in the f-orbital ligand field splitting.

  3. Basis set limit geometries for ammonia at the SCF and MP2 levels of theory

    NASA Technical Reports Server (NTRS)

    Defrees, D. J.; Mclean, A. D.

    1984-01-01

    The controversy over the Hartree-Fock bond angle of NH3 is resolved and the convergence of the geometry for the molecule as the basis set is systematically improved with both SCF and correlated MP2 wave functions. The results of the geometrical optimizations, carried out in four stages with a series of uncontracted bases sets, are shown. The obtained structure for NH3 supports the results of Radom and Rodwell (1980) that the Hartree-Fock limit angle is significantly greater than was previously believed.

  4. The Brain in Space: A Teacher's Guide with Activities for Neuroscience.

    ERIC Educational Resources Information Center

    MacLeish, Marlene Y.; McLean, Bernice R.

    This educators guide discusses the brain and contains activities on neuroscience. Activities include: (1) "The Space Life Sciences"; (2) "Space Neuroscience: A Special Area within the Space Life Sciences"; (3) "Space Life Sciences Research"; (4) "Neurolab: A Special Space Mission to Study the Nervous System"; (5) "The Nervous System"; (6)…

  5. Assessing acoustic communication active space in the Lusitanian toadfish.

    PubMed

    Alves, Daniel; Amorim, M Clara P; Fonseca, Paulo J

    2016-04-15

    The active space of a signal is an important concept in acoustic communication as it has implications for the function and evolution of acoustic signals. However, it remains mostly unknown for fish as it has been measured in only a restricted number of species. We combined physiological and sound propagation approaches to estimate the communication range of the Lusitanian toadfish's ( ITALIC! Halobatrachus didactylus) advertisement sound, the boatwhistle (BW). We recorded BWs at different distances from vocalizing fish in a natural nesting site at ca. 2-3 m depth. We measured the representation of these increasingly attenuated BWs in the auditory pathway through the auditory evoked potential (AEP) technique. These measurements point to a communication range of between 6 and 13 m, depending on the spectral characteristics of the BW. A similar communication range (ca. 8 m) was derived from comparing sound attenuation at selected frequencies with auditory sensitivity. This is one of the few studies to combine auditory measurements with sound propagation to estimate the active space of acoustic signals in fish. We emphasize the need in future studies for estimates of active space to take informational masking into account. PMID:26896547

  6. Space.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2001

    2001-01-01

    This annotated subject guide to Web sites and additional resources focuses on space and astronomy. Specifies age levels for resources that include Web sites, CD-ROMS and software, videos, books, audios, and magazines; offers professional resources; and presents a relevant class activity. (LRW)

  7. Active and passive vibration suppression for space structures

    NASA Technical Reports Server (NTRS)

    Hyland, David C.

    1991-01-01

    The relative benefits of passive and active vibration suppression for large space structures (LSS) are discussed. The intent is to sketch the true ranges of applicability of these approaches using previously published technical results. It was found that the distinction between active and passive vibration suppression approaches is not as sharp as might be thought at first. The relative simplicity, reliability, and cost effectiveness touted for passive measures are vitiated by 'hidden costs' bound up with detailed engineering implementation issues and inherent performance limitations. At the same time, reliability and robustness issues are often cited against active control. It is argued that a continuum of vibration suppression measures offering mutually supporting capabilities is needed. The challenge is to properly orchestrate a spectrum of methods to reap the synergistic benefits of combined advanced materials, passive damping, and active control.

  8. A New Active Space Radiation Instruments for the International Space Station, A-DREAMS

    NASA Astrophysics Data System (ADS)

    Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Kobayashi, Shingo

    For future space experiments in the International Space Station (ISS) or other satellites, radiation detectors, A-DREAMS (Active Dosimeter for Radiation Environment and Astronautic Monitoring in Space), using single or multiple silicon semi-conductor detectors have been developed. The first version of the detectors were produced and calibrated with particle accelerators. National Institute of Radiological Sciences has a medical heavy ion accelerator (HIMAC) for cancer therapy and a cyclotron accelerator. The detector was irradiated with high energy heavy ions and protons in HIMAC and the cyclotron and calibrated the energy resolution and linearity for deposited energies of these particles. We are planned to be going to use the new instrument in an international project, the new MATROSHKA experiment which is directed by members in the Institute of Bio-Medical Problem (IBMP) in Russia and German Space Center (DLR) in Germany. In the project, the dose distribution in human torso phantom will be investigated for several months in the ISS. For the project, a new type of the instruments is under development in NIRS and the current situation will be reported in this paper.

  9. NASA Aerosciences Activities to Support Human Space Flight

    NASA Technical Reports Server (NTRS)

    LeBeau, Gerald J.

    2011-01-01

    The Lyndon B. Johnson Space Center (JSC) has been a critical element of the United State's human space flight program for over 50 years. It is the home to NASA s Mission Control Center, the astronaut corps, and many major programs and projects including the Space Shuttle Program, International Space Station Program, and the Orion Project. As part of JSC's Engineering Directorate, the Applied Aeroscience and Computational Fluid Dynamics Branch is charted to provide aerosciences support to all human spacecraft designs and missions for all phases of flight, including ascent, exo-atmospheric, and entry. The presentation will review past and current aeroscience applications and how NASA works to apply a balanced philosophy that leverages ground testing, computational modeling and simulation, and flight testing, to develop and validate related products. The speaker will address associated aspects of aerodynamics, aerothermodynamics, rarefied gas dynamics, and decelerator systems, involving both spacecraft vehicle design and analysis, and operational mission support. From these examples some of NASA leading aerosciences challenges will be identified. These challenges will be used to provide foundational motivation for the development of specific advanced modeling and simulation capabilities, and will also be used to highlight how development activities are increasing becoming more aligned with flight projects. NASA s efforts to apply principles of innovation and inclusion towards improving its ability to support the myriad of vehicle design and operational challenges will also be briefly reviewed.

  10. Carbon Nanotube Activities at NASA-Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Arepalli, Sivaram

    2006-01-01

    Research activities on carbon nanotubes at NASA-Johnson Space Center include production, purification, characterization and their applications for human space flight. In-situ diagnostics during nanotube production by laser oven process include collection of spatial and temporal data of passive emission and laser induced fluorescence from C2, C3 and Nickel atoms in the plume. Details of the results from the "parametric study" of the pulsed laser ablation process indicate the effect of production parameters including temperature, buffer gas, flow rate, pressure, and laser fluence. Improvement of the purity by a variety of steps in the purification process is monitored by characterization techniques including SEM, TEM, Raman, UV-VIS-NIR and TGA. A recently established NASA-JSC protocol for SWCNT characterization is undergoing revision with feedback from nanotube community. Efforts at JSC over the past five years in composites have centered on structural polymednanotube systems. Recent activities broadened this focus to multifunctional materials, supercapacitors, fuel cells, regenerable CO2 absorbers, electromagnetic shielding, radiation dosimetry and thermal management systems of interest for human space flight. Preliminary tests indicate improvement of performance in most of these applications because of the large surface area as well as high electrical and thermal conductivity exhibited by SWCNTs.

  11. [Evaluation of the treatment effectiveness of domestic G-SCF preparations in experiments on irradiated dogs].

    PubMed

    Rozhdestvenskiĭ, L M; Shliakova, T G; Shchegoleva, R A; Lisina, N I; Zorin, V V

    2013-01-01

    We have evaluated the treatment effectiveness of Leucostim and Neupomax in dogs exposed to radiation at lethal doses of 3 and 3.5 Gy, correspondingly, by testing the dynamics of the blood cell number, first of all, leucocytes and neutrophiles, and the 45-day survival. Supportive therapy for all the dogs, including the control ones, consisted in antibiotic treatment during the acute period of 7-24 days. It was shown that both pre-parations administered consecutively for about 17-21 days after irradiation positively influenced the dynamics of all blood cells but predominantly impacted the neutrophile number dynamics. The latter ones manifested a higher nadir level and an earlier onset of restoration in the G-SCF treated dogs in comparison with the control ones. The tendency to a positive influence on the survival has been shown in Neupomax-treated dogs exposed to 3.5 Gy of radiation (plus about 40%). The results of the experiments were in good accordance with the data by foreign authors who used Neupogen. This allows a conclusion that home-produced G-SCF preparations can replace their foreign analogues. PMID:23700834

  12. An SCF complex containing Fbxl12 mediates DNA damage-induced Ku80 ubiquitylation

    PubMed Central

    Postow, Lisa; Funabiki, Hironori

    2013-01-01

    The Ku heterodimer, composed of Ku70 and Ku80, is the initiating factor of the nonhomologous end joining (NHEJ) double-strand break (DSB) repair pathway. Ku is also thought to impede the homologous recombination (HR) repair pathway via inhibition of DNA end resection. Using the cell-free Xenopus laevis egg extract system, we had previously discovered that Ku80 becomes polyubiquitylated upon binding to DSBs, leading to its removal from DNA and subsequent proteasomal degradation. Here we show that the Skp1-Cul1-F box (SCF) E3 ubiquitin ligase complex is required for Ku80 ubiquitylation and removal from DNA. A screen for DSB-binding F box proteins revealed that the F box protein Fbxl12 was recruited to DNA in a DSB- and Ku-sensitive manner. Immunodepletion of Fbxl12 prevented Cul1 and Skp1 binding to DSBs and Ku80 ubiquitylation, indicating that Fbxl12 is the F box protein responsible for Ku80 substrate recognition. Unlike typical F box proteins, the F box of Fbxl12 was essential for binding to both Skp1 and its substrate Ku80. Besides Fbxl12, six other chromatin-binding F box proteins were identified in our screen of a subset of Xenopus F box proteins: β-TrCP, Fbh1, Fbxl19, Fbxo24, Fbxo28 and Kdm2b. Our study unveils a novel function for the SCF ubiquitin ligase in regulating the dynamic interaction between DNA repair machineries and DSBs. PMID:23324393

  13. Design and process aspects of laboratory scale SCF particle formation systems.

    PubMed

    Vemavarapu, Chandra; Mollan, Matthew J; Lodaya, Mayur; Needham, Thomas E

    2005-03-23

    Consistent production of solid drug materials of desired particle and crystallographic morphologies under cGMP conditions is a frequent challenge to pharmaceutical researchers. Supercritical fluid (SCF) technology gained significant attention in pharmaceutical research by not only showing a promise in this regard but also accommodating the principles of green chemistry. Given that this technology attained commercialization in coffee decaffeination and in the extraction of hops and other essential oils, a majority of the off-the-shelf SCF instrumentation is designed for extraction purposes. Only a selective few vendors appear to be in the early stages of manufacturing equipment designed for particle formation. The scarcity of information on the design and process engineering of laboratory scale equipment is recognized as a significant shortcoming to the technological progress. The purpose of this article is therefore to provide the information and resources necessary for startup research involving particle formation using supercritical fluids. The various stages of particle formation by supercritical fluid processing can be broadly classified into delivery, reaction, pre-expansion, expansion and collection. The importance of each of these processes in tailoring the particle morphology is discussed in this article along with presenting various alternatives to perform these operations. PMID:15725549

  14. Size effects on negative thermal expansion in cubic ScF3

    NASA Astrophysics Data System (ADS)

    Yang, C.; Tong, P.; Lin, J. C.; Guo, X. G.; Zhang, K.; Wang, M.; Wu, Y.; Lin, S.; Huang, P. C.; Xu, W.; Song, W. H.; Sun, Y. P.

    2016-07-01

    Scandium trifluoride (ScF3), adopting a cubic ReO3-type structure at ambient pressure, undergoes a pronounced negative thermal expansion (NTE) over a wide range of temperatures (10 K-1100 K). Here, we report the size effects on the NTE properties of ScF3. The magnitude of NTE is reduced with diminishing the crystal size. As revealed by the specific heat measurement, the low-energy phonon vibrations which account for the NTE behavior are stiffened as the crystal size decreases. With decreasing the crystal size, the peaks in high-energy X-ray pair distribution function (PDF) become broad, which cannot be illuminated by local symmetry breaking. Instead, the broadened PDF peaks are strongly indicative of enhanced atomic displacements which are suggested to be responsible for the stiffening of NTE-related lattice vibrations. The present study suggests that the NTE properties of ReO3-type and other open-framework materials can be effectively adjusted by controlling the crystal size.

  15. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    SciTech Connect

    DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca; Simmons, Blake A.; Isern, Nancy G.; Markillie, Lye Meng; Nicora, Carrie D.; Norbeck, Angela D.; Taylor, Ronald C.; Aldrich, Joshua T.; Robinson, Errol W.

    2013-08-29

    The anaerobic isolate Enterobacter lignolyticus SCF1 was initially cultivated based on anaerobic growth on lignin as sole carbon source. The source of the isolated bacteria was from tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, making it likely that bacteria using oxygen-independent enzymes play an important role in decomposition. We have examined differential expression of the anaerobic isolate Enterobacter lignolyticus SCF1 during growth on lignin. After 48 hours of growth, we used transcriptomics and proteomics to define the enzymes and other regulatory machinery that these organisms use to degrade lignin, as well as metabolomics to measure lignin degradation and monitor the use of lignin and iron as terminal electron acceptors that facilitate more efficient use of carbon. Proteomics revealed accelerated xylose uptake and metabolism under lignin-amended growth, and lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. Our data shows the advantages of a multi-omics approach, where incomplete pathways identified by genomics were completed, and new observations made on coping with poor carbon availability. The fast growth, high efficiency and specificity of enzymes employed in bacterial anaerobic litter deconstruction makes these soils useful templates for improving biofuel production.

  16. European Space Agency detector development for space science: present and future activities

    NASA Astrophysics Data System (ADS)

    Duvet, L.; Bavdaz, M.; Crouzet, P. E.; Nelms, N.; Nowicki-Bringuier, Y. R.; Shortt, B.; Verhoeve, P.

    2014-07-01

    We report on the present and future detector development activities for the European Space Agency Science Programme. The development of European technology in that field is a key mission enabler for the program, which requires TRL6 (ISO scale) by end of the definition phase, so called "mission adoption". This is particularly true for Astronomy and fundamental physics type missions. Current activities are in particular targeting large format and p-channel CCD, NIR and MWIR, LWIR wavelength ranges as well as related ASIC controller. For the longer term future mission plan (so called M4, M5 and L2 missions, M3 being PLATO and L1 JUICE), the extreme ends of the spectrum will be addressed. An overview of the detector status for the Earth Observation program is given in appendix, as most of the technologies are directly applicable to some extent to science missions, in particular for Planetary missions. The specific validation activities in place in the future mission preparation office in support to the space science program will be eventually briefly detailed.

  17. Spacing of Rocky Mountain foreland arches and Laramide magmatic activity

    SciTech Connect

    Schmidt, C.J.; Evans, J.P.; Fletcher, R.C.; Spang, J.H.

    1985-01-01

    First-order Late Cretaceous and Paleocene folds in the Rocky Mountain foreland have a spacing (S) ranging from 45 to 300 km. Spacing of folds and major mountain flank thrusts was controlled in part by the depth of the brittle-ductile transition (BDT). Analysis of folding of a brittle layer of thickness H above a ductile substrate suggests S/H approx. = 4-6. Experimental data indicate that the BDT in quartz rich rock occurs at 300/sup 0/ +/- 50/sup 0/C and therefore its depth depends on geothermal gradient. Regions with high Laramide geothermal gradients should have had a shallower depth to the BDT and a shorter spacing of first-order folds than regions with low gradients. A regional compilation for the Montana and Wyoming foreland shows a correlation between the value of S and syntectonic magmatic activity. The mean S value for southwestern Montana, where Late Cretaceous and Paleocene magmatic activity was widespread, is 65 km. This value of S indicates a relatively shallow (11-16 km) depth of the BDT and suggests a relatively high (16-32/sup 0/C/km) Laramide geothermal gradient. The mean S value for the Wyoming foreland, where no syntectonic magmatic activity is indicated, is 150 km. Measurements of S may allow some predictions of depth to rheologically-controlled mid-crustal decoupling zones. They may also indicate areas where the depth to the BDT was not a major control on S. Structures with S < 40 km correspond to inadmissably shallow BDT zones and were probably controlled by other factors such as preexisting fault zones or basement lithology.

  18. A precision, thermally-activated driver for space application

    NASA Technical Reports Server (NTRS)

    Murray, Robert C.; Walsh, Robert F.; Kinard, William H.

    1986-01-01

    A space qualified, precision, large force, thermally-activated driver that has been developed jointly by the NASA Langley Research Center and PRC Kentron is described. The driver consists of a sealed hydraulic cylinder containing a metal bellows, a bellows plug, a coil spring, a spring retainer, and output shaft, a shaft guide, and a quantity of silicone oil. Temperature changes cause the silicone oil to expand or contract thus contracting or expanding the bellows/spring assembly thereby extending or retracting the output shaft.

  19. Space Power Amplification with Active Linearly Tapered Slot Antenna Array

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1993-01-01

    A space power amplifier composed of active linearly tapered slot antennas (LTSA's) has been demonstrated and shown to have a gain of 30 dB at 20 GHz. In each of the antenna elements, a GaAs monolithic microwave integrated circuit (MMIC) three-stage power amplifier is integrated with two LTSA's. The LTSA and the MMIC power amplifier has a gain of 11 dB and power added efficiency of 14 percent respectively. The design is suitable for constructing a large array using monolithic integration techniques.

  20. Optimum mix of passive and active control of space structures

    NASA Technical Reports Server (NTRS)

    Rogers, Lynn; Richards, Ken

    1987-01-01

    The objective of this research was to test vibration suppression (settling time and jitter) of a large space structure (LSS) characterized by low frequency high global vibration modes. Five percent passive damping in a large truss was analyzed, tested and correlated. A representative system article re-target analysis shows that modest levels of passive damping dramatically reduce the control energy required. LSS must incorporate passive damping from the outset. The LSS system performance will not be met by either active or passive damping alone.

  1. Mechanisms of the Space Active Vibration Isolation (SAVI)

    NASA Technical Reports Server (NTRS)

    Schmitt, Frank

    1992-01-01

    The Space Active Vibration Isolation (SAVI) is a concept for vibration isolation of one body from another with simultaneous precise control in 6 Degrees Of Freedom (DOF). SAVI achieves this using a combination of electromechanical linear actuators and magnetic actuators. Other mechanisms of interest include a structure for simulating the body being pointed, an apparatus to simulate the body that is the vibration source, and mechanisms to off-load the weight of each of these two bodies from the experiment to approximate a zero-g condition. A SAVI was built and tested to demonstrate these capabilities.

  2. Space Suit CO2 Washout During Intravehicular Activity

    NASA Technical Reports Server (NTRS)

    Augustine, Phillip M.; Navarro, Moses; Conger, Bruce; Sargusingh, Miriam M.

    2010-01-01

    Space suit carbon dioxide (CO2) washout refers to the removal of CO2 gas from the oral-nasal area of a suited astronaut's (or crewmember's) helmet using the suit's ventilation system. Inadequate washout of gases can result in diminished mental/cognitive abilities as well as headaches and light headedness. In addition to general discomfort, these ailments can impair an astronaut s ability to perform mission-critical tasks ranging from flying the space vehicle to performing lunar extravehicular activities (EVAs). During design development for NASA s Constellation Program (CxP), conflicting requirements arose between the volume of air flow that the new Orion manned space vehicle is allocated to provide to the suited crewmember and the amount of air required to achieve CO2 washout in a space suit. Historically, space suits receive 6.0 actual cubic feet per minute (acfm) of air flow, which has adequately washed out CO2 for EVAs. For CxP, the Orion vehicle will provide 4.5 acfm of air flow to the suit. A group of subject matter experts (SM Es) among the EVA Systems community came to an early consensus that 4.5 acfm may be acceptable for low metabolic rate activities. However, this value appears very risky for high metabolic rates, hence the need for further analysis and testing. An analysis was performed to validate the 4.5 acfm value and to determine if adequate CO2 washout can be achieved with the new suit helmet design concepts. The analysis included computational fluid dynamic (CFD) modeling cases, which modeled the air flow and breathing characteristics of a human wearing suit helmets. Helmet testing was performed at the National Institute of Occupational Safety and Health (NIOSH) in Pittsburgh, Pennsylvania, to provide a gross-level validation of the CFD models. Although there was not a direct data correlation between the helmet testing and the CFD modeling, the testing data showed trends that are very similar to the CFD modeling. Overall, the analysis yielded

  3. Searching the Future for the Legal Regime of Space Activities: the Need for Unification of National Space Legislation' Provisions

    NASA Astrophysics Data System (ADS)

    Negoda, S. A.

    2002-01-01

    space activities. For the future legal regime of space activities it is vital to preserve the existed principles and main provisions of the international space law. related legislations are developing rapidly. They become serious instrument for legal regulation of space activities. those projects with a foreign party involvement. Quite often partners in international space projects agree to choice a domestic law of one of them. They do this for defining a certain organizational and/or contractual issue (disputes settlement, for example) of the project. that such practice will spread widely. could help to preserve the existed important provisions of international space law (responsibility of states for their national activities, for instance). development of international space private law. We believe that solely special laws and regulations of national legislations could not regulate modern space activities. Being more and more commercial, space activities are becoming a real part of "downed to Earth" commercial activities. Therefore, in many countries provisions of civil, commercial, investment and other branches of national law are applied to such activities. which could low possible risks of such activities and to control them. Such unification seems to be suitable in the following fields: 1)implementation of provisions of international space law in national space laws; 2)definition of unified terminology, accepted by national laws of all parties; 3)unification in national legislations of a certain standards (insurance rates and rules, for instance); 4)unification in national laws of issues related to liability (for instance, a mutual wave of liability in certain types of 5)implementation in national laws of unified rules and procedures of space-related commercial disputes settlement; 6)unification of mechanisms for protection of space-related intellectual property. unification of their provisions. Special attention is paid to provisions of private law

  4. Plasma Hazards and Acceptance for International Space Station Extravehicular Activities

    NASA Astrophysics Data System (ADS)

    Patton, Thomas

    2010-09-01

    Extravehicular activity(EVA) is accepted by NASA and other space faring agencies as a necessary risk in order to build and maintain a safe and efficient laboratory in space. EVAs are used for standard construction and as contingency operations to repair critical equipment for vehicle sustainability and safety of the entire crew in the habitable volume. There are many hazards that are assessed for even the most mundane EVA for astronauts, and the vast majority of these are adequately controlled per the rules of the International Space Station Program. The need for EVA repair and construction has driven acceptance of a possible catastrophic hazard to the EVA crewmember which cannot currently be controlled adequately. That hazard is electrical shock from the very environment in which they work. This paper describes the environment, causes and contributors to the shock of EVA crewmembers attributed to the ionospheric plasma environment in low Earth orbit. It will detail the hazard history, and acceptance process for the risk associated with these hazards that give assurance to a safe EVA. In addition to the hazard acceptance process this paper will explore other factors that go into the decision to accept a risk including criticality of task, hardware design and capability, and the probability of hazard occurrence. Also included will be the required interaction between organizations at NASA(EVA Office, Environments, Engineering, Mission Operations, Safety) in order to build and eventually gain adequate acceptance rationale for a hazard of this kind. During the course of the discussion, all current methods of mitigating the hazard will be identified. This paper will capture the history of the plasma hazard analysis and processes used by the International Space Station Program to formally assess and qualify the risk. The paper will discuss steps that have been taken to identify and perform required analysis of the floating potential shock hazard from the ISS environment

  5. Active space debris charging for contactless electrostatic disposal maneuvers

    NASA Astrophysics Data System (ADS)

    Schaub, Hanspeter; Sternovsky, Zoltán

    2014-01-01

    The remote charging of a passive object using an electron beam enables touchless re-orbiting of large space debris from geosynchronous orbit (GEO) using electrostatic forces. The advantage of this method is that it can operate with a separation distance of multiple craft radii, thus reducing the risk of collision. The charging of the tug-debris system to high potentials is achieved by active charge transfer using a directed electron beam. Optimal potential distributions using isolated- and coupled-sphere models are discussed. A simple charging model takes into account the primary electron beam current, ultra-violet radiation induced photoelectron emission, collection of plasma particles, secondary electron emission and the recapture of emitted particles. The results show that through active charging in a GEO space environment high potentials can be both achieved and maintained with about a 75% transfer efficiency. Further, the maximum electrostatic tractor force is shown to be insensitive to beam current levels. This latter later result is important when considering debris with unknown properties.

  6. Nanotube Activities at NASA-Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Arepalli, Sivaram

    2004-01-01

    Nanotube activities at NASA-Johnson Space Center include production, purification, characterization as well as applications of single wall carbon nanotubes (SWCNTs). A parametric study of the pulsed laser ablation process is recently completed to monitor the effect of production parameters including temperature, buffer gas, flow rate, pressure, and laser fluence. Enhancement of production is achieved by rastering the graphite target and by increasing the target surface temperature with a cw laser. In-situ diagnostics during production included time resolved passive emission and laser induced fluorescence from the plume. The improvement of the purity by a variety of steps in the purification process is monitored by characterization techniques including SEM, TEM, Raman, UV-VIS-NIR and TGA. A recently established NASA-JSC protocol for SWCNT characterization is undergoing revision with feedback from nanotube community. Efforts at JSC over the past five years in composites have centered on structural polymer/nanotube systems. Recent activities broadened this focus to multifunctional materials, supercapacitors, fuel cells, regenerable CO2 absorbers, electromagnetic shielding, radiation dosimetry and thermal management systems of interest for human space flight. Preliminary tests indicate improvement of performance in most of these applications because of the large Surface area as well as high electrical and thermal conductivity exhibited by SWCNTs. Comparison with existing technologies and possible future improvements in the SWCNT materials sill be presented.

  7. On the relation between adiabatic time dependent density functional theory (TDDFT) and the ΔSCF-DFT method. Introducing a numerically stable ΔSCF-DFT scheme for local functionals based on constricted variational DFT

    NASA Astrophysics Data System (ADS)

    Park, Young Choon; Krykunov, Mykhaylo; Ziegler, Tom

    2015-07-01

    In ΔSCF density functional theory studies of a i → a transition one performs separate fully self-consistent field calculations on the ground state configuration (i)n (n = 1,2) and the excited state configuration (i)n - 1a. The excitation energy for the transition i → a is subsequently determined as the Kohn-Sham energy difference ΔEi → a = E[in - 1a] - E[in] between the ground state (i)n and the excited state configuration (i)n - 1a. The ΔSCF scheme has been applied extensively and works well for lower energy excitations provided that they can be represented by a single orbital replacement or transition i → a. However, for excitations of higher energy ΔSCF tends to become numerically unstable with a variational collapse to transitions of lower energy. We demonstrate here a numerically stable ΔSCF scheme for local functionals that is guaranteed not to collapse on excited configurations of lower energy as well as the ground state. The new scheme is based on constricted variational density functional theory in which the canonical ground state orbitals are allowed to relax (R-CV(∞)-DFT). Since it is restricted to a single orbital replacement i → a it is termed SOR-R-CV(∞)-DFT.

  8. Space active optics: performance of a deformable mirror for in-situ wave-front correction in space telescopes

    NASA Astrophysics Data System (ADS)

    Laslandes, Marie; Hourtoule, Claire; Hugot, Emmanuel; Ferrari, Marc; Lopez, Céline; Devilliers, Christophe; Liotard, Arnaud; Chazallet, Frederic

    2012-09-01

    MADRAS (Mirror Active, Deformable and Regulated for Applications in Space) project aims at demonstrating the interest of Active Optics for space applications. We present the prototype of a 24 actuators, 100 mm diameter deformable mirror to be included in a space telescope's pupil relay to compensate for large lightweight primary mirror deformation. The mirror design has been optimized with Finite Element Analysis and its experimental performance characterized in representative conditions. The developed deformable mirror provides an efficient wave-front correction with a limited number of actuators and a design fitting space requirements.

  9. 48 CFR 1828.371 - Clauses incorporating cross-waivers of liability for International Space Station activities and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cross-waivers of liability for International Space Station activities and Science or Space Exploration... Station activities and Science or Space Exploration activities unrelated to the International Space Station. (a) In contracts covering International Space Station activities, or Science or Space...

  10. 48 CFR 1828.371 - Clauses incorporating cross-waivers of liability for International Space Station activities and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cross-waivers of liability for International Space Station activities and Science or Space Exploration... Station activities and Science or Space Exploration activities unrelated to the International Space Station. (a) In contracts covering International Space Station activities, or Science or Space...

  11. Supercritical fluid (SCF) technologies: Assessment of applicability to installation restoration processes

    NASA Astrophysics Data System (ADS)

    1994-03-01

    USAEC has conducted an evaluation of supercritical fluid (SCF) technologies for their applicability to treatment of explosives, chlorinated hydrocarbons, and metals in soils, water, and/or waste sludge media. Off-specification explosives and propellants that have traditionally been open burned or openly detonated were also examined. Supercritical fluids are substances which have been heated and compressed to above their critical temperatures and pressures and which possess unique transport and mass transfer properties. Supercritical fluid extraction (SFE) uses the solvating properties of supercritical fluids to extract one or more organic components from a mixture into a supercritical solvent (commonly CO2). The concentrated extract stream may then be recycled, reclaimed, or destroyed by other methods.

  12. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    PubMed Central

    DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca; Simmons, Blake; Isern, Nancy G.; Markilllie, Lye Meng; Nicora, Carrie; Norbeck, Angela D.; Taylor, Ronald C.; Aldrich, Joshua T.; Robinson, Errol W.

    2013-01-01

    Lignocellulosic biofuels are promising as sustainable alternative fuels, but lignin inhibits access of enzymes to cellulose, and by-products of lignin degradation can be toxic to cells. The fast growth, high efficiency and specificity of enzymes employed in the anaerobic litter deconstruction carried out by tropical soil bacteria make these organisms useful templates for improving biofuel production. The facultative anaerobe Enterobacter lignolyticus SCF1 was initially cultivated from Cloud Forest soils in the Luquillo Experimental Forest in Puerto Rico, based on anaerobic growth on lignin as sole carbon source. The source of the isolate was tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, where bacteria using oxygen-independent enzymes likely play an important role in decomposition. We have used transcriptomics and proteomics to examine the observed increased growth of SCF1 grown on media amended with lignin compared to unamended growth. Proteomics suggested accelerated xylose uptake and metabolism under lignin-amended growth, with up-regulation of proteins involved in lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase (GST) proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. This suggested the use of lignin as terminal electron acceptor. We detected significant lignin degradation over time by absorbance, and also used metabolomics to demonstrate moderately significant decreased xylose concentrations as well as increased metabolic products acetate and formate in stationary phase in lignin-amended compared to unamended growth conditions. Our data show the advantages of a multi-omics approach toward providing insights as to how lignin may be used in nature by microorganisms coping

  13. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1.

    PubMed

    Deangelis, Kristen M; Sharma, Deepak; Varney, Rebecca; Simmons, Blake; Isern, Nancy G; Markilllie, Lye Meng; Nicora, Carrie; Norbeck, Angela D; Taylor, Ronald C; Aldrich, Joshua T; Robinson, Errol W

    2013-01-01

    Lignocellulosic biofuels are promising as sustainable alternative fuels, but lignin inhibits access of enzymes to cellulose, and by-products of lignin degradation can be toxic to cells. The fast growth, high efficiency and specificity of enzymes employed in the anaerobic litter deconstruction carried out by tropical soil bacteria make these organisms useful templates for improving biofuel production. The facultative anaerobe Enterobacter lignolyticus SCF1 was initially cultivated from Cloud Forest soils in the Luquillo Experimental Forest in Puerto Rico, based on anaerobic growth on lignin as sole carbon source. The source of the isolate was tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, where bacteria using oxygen-independent enzymes likely play an important role in decomposition. We have used transcriptomics and proteomics to examine the observed increased growth of SCF1 grown on media amended with lignin compared to unamended growth. Proteomics suggested accelerated xylose uptake and metabolism under lignin-amended growth, with up-regulation of proteins involved in lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase (GST) proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. This suggested the use of lignin as terminal electron acceptor. We detected significant lignin degradation over time by absorbance, and also used metabolomics to demonstrate moderately significant decreased xylose concentrations as well as increased metabolic products acetate and formate in stationary phase in lignin-amended compared to unamended growth conditions. Our data show the advantages of a multi-omics approach toward providing insights as to how lignin may be used in nature by microorganisms coping

  14. Composite low affinity interactions dictate recognition of the cyclin-dependent kinase inhibitor Sic1 by the SCF[superscript Cdc4] ubiquitin ligase

    SciTech Connect

    Tang, Xiaojing; Orlicky, Stephen; Mittag, Tanja; Csizmok, Veronika; Pawson, Tony; Forman-Kay, Julie D.; Sicheri, Frank; Tyers, Mike

    2012-05-24

    The ubiquitin ligase SCF{sup Cdc4} (Skp1/Cul1/F-box protein) recognizes its substrate, the cyclin-dependent kinase inhibitor Sic1, in a multisite phosphorylation-dependent manner. Although short diphosphorylated peptides derived from Sic1 can bind to Cdc4 with high affinity, through systematic mutagenesis and quantitative biophysical analysis we show that individually weak, dispersed Sic1 phospho sites engage Cdc4 in a dynamic equilibrium. The affinities of individual phosphoepitopes serve to tune the overall phosphorylation site threshold needed for efficient recognition. Notably, phosphoepitope affinity for Cdc4 is dramatically weakened in the context of full-length Sic1, demonstrating the importance of regional environment on binding interactions. The multisite nature of the Sic1-Cdc4 interaction confers cooperative dependence on kinase activity for Sic1 recognition and ubiquitination under equilibrium reaction conditions. Composite dynamic interactions of low affinity sites may be a general mechanism to establish phosphorylation thresholds in biological responses.

  15. SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling – potential applications as a homing factor in dental pulp regeneration

    PubMed Central

    Pan, Shuang; Dangaria, Smit; Gopinathan, Gokul; Yan, Xiulin; Lu, Xuanyu; Kolokythas, Antonia; Niu, Yumei; Luan, Xianghong

    2014-01-01

    Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 hour culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 minutes after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling. PMID:23703692

  16. Development of an active magnetic regenerator for space applications

    NASA Astrophysics Data System (ADS)

    Chen, Weibo

    2014-07-01

    This paper discusses the design of a micromachined regenerator in an Active Magnetic Regenerative Refrigeration (AMRR) system for space applications. The AMRR system is designed to provide continuous remote/distributed cooling at about 2 K and reject heat at temperatures of about 15 K. This paper first discusses the general thermal and fluid performance requirements for an AMRR regenerator, a unique structured bed configuration that enables the regenerator to meet these requirements, and its thermal and fluid performance based on numerical analyses. The paper then discusses the general design consideration for the magnetic field driving the regenerator for optimal thermal performance, and the analysis processes to optimize the variation rate of the magnetic field in an actual superconducting magnet during the isothermal processes of the AMRR cycle to enhance the performance of an actual regenerator. The paper finally presents the thermal performance of the regenerator from such iterative design optimization processes.

  17. Computer modeling of active experiments in space plasmas

    NASA Astrophysics Data System (ADS)

    Bollens, Ross John

    1993-01-01

    Our understanding of space plasmas is expanding rapidly. This is, in large part, due to the ambitious efforts of scientists from around the world who are performing large scale active experiments in the space plasma surrounding the earth. One such effort was designated the Active Magnetospheric Particle Tracer Explorers (AMPTE) and consisted of a series of plasma releases that were completed during 1984 and 1985. What makes the AMPTE experiments particularly interesting was the occurrence of a dramatic anomaly that was completely unpredicted. During the AMPTE experiment, three satellites traced the solar wind flow into the earth's magnetosphere. One satellite, built by West Germany, released a series of barium and lithium canisters that were detonated and subsequently photoionized via solar radiation, thereby creating an artificial comet. Another satellite, built by Great Britain and in the vicinity during detonation, carried, as did the first satellite, a comprehensive set of magnetic field, particle, and wave instruments. Upon detonation, what was observed by the satellites, as well as by aircraft and ground-based observers, was quite unexpected. The initial deflection of the ion clouds was not in the ambient solar wind's flow direction (V) but rather in the direction transverse to the solar wind and the background magnetic field (V x B). This result was not predicted by any existing theories or simulation models; it is the main subject discussed in this dissertation. A large three dimensional computer simulation was produced to demonstrate that this transverse motion can be explained in terms of a rocket effect. Due to the extreme computer resources utilized in producing this work, the computer methods used to complete the calculation and the visualization techniques used to view the results are also discussed.

  18. Multiple Orientia tsutsugamushi Ankyrin Repeat Proteins Interact with SCF1 Ubiquitin Ligase Complex and Eukaryotic Elongation Factor 1 α

    PubMed Central

    Min, Chan-Ki; Kwon, Ye-Jin; Ha, Na-Young; Cho, Bon-A; Kim, Jo-Min; Kwon, Eun-Kyung; Kim, Yeon-Sook; Choi, Myung-Sik; Kim, Ik-Sang; Cho, Nam-Hyuk

    2014-01-01

    Background Orientia tsutsugamushi, the causative agent of scrub typhus, is an obligate intracellular bacterium. Previously, a large number of genes that encode proteins containing eukaryotic protein-protein interaction motifs such as ankyrin-repeat (Ank) domains were identified in the O. tsutsugamushi genome. However, little is known about the Ank protein function in O. tsutsugamushi. Methodology/Principal Findings To characterize the function of Ank proteins, we investigated a group of Ank proteins containing an F-box–like domain in the C-terminus in addition to the Ank domains. All nine selected ank genes were expressed at the transcriptional level in host cells infected with O. tsutsugamushi, and specific antibody responses against three Ank proteins were detected in the serum from human patients, indicating an active expression of the bacterial Ank proteins post infection. When ectopically expressed in HeLa cells, the Ank proteins of O. tsutsugamushi were consistently found in the nucleus and/or cytoplasm. In GST pull-down assays, multiple Ank proteins specifically interacted with Cullin1 and Skp1, core components of the SCF1 ubiquitin ligase complex, as well as the eukaryotic elongation factor 1 α (EF1α). Moreover, one Ank protein co-localized with the identified host targets and induced downregulation of EF1α potentially via enhanced ubiquitination. The downregulation of EF1α was observed consistently in diverse host cell types infected with O. tsutsugamushi. Conclusion/Significance These results suggest that conserved targeting and subsequent degradation of EF1α by multiple O. tsutsugamushi Ank proteins could be a novel bacterial strategy for replication and/or pathogenesis during mammalian host infection. PMID:25166298

  19. Simian virus 40 large T antigen's association with the CUL7 SCF complex contributes to cellular transformation.

    PubMed

    Kasper, Jocelyn S; Kuwabara, Hiroshi; Arai, Takehiro; Ali, Syed Hamid; DeCaprio, James A

    2005-09-01

    Simian virus 40 large T antigen (T Ag) is capable of immortalizing and transforming rodent cells. The transforming activity of T Ag is due in large part to perturbation of the tumor suppressor proteins p53 and the retinoblastoma (pRB) family members. Inactivation of these tumor suppressors may not be sufficient for T Ag-mediated cellular transformation. It has been shown that T Ag associates with an SCF-like complex that contains a member of the cullin family of E3 ubiquitin ligases, CUL7, as well as SKP1, RBX1, and an F-box protein, FBXW8. We identified T Ag residues 69 to 83 as required for T Ag binding to the CUL7 complex. We demonstrate that delta69-83 T Ag, while it lost its ability to associate with CUL7, retained binding to p53 and pRB family members. In the presence of CUL7, wild-type (WT) T Ag but not delta69-83 T Ag was able to induce proliferation of mouse embryo fibroblasts, an indication of cellular transformation. In contrast, WT and delta69-83 T Ag enabled mouse embryo fibroblasts to proliferate to similarly high densities in the absence of CUL7. Our data suggest that, in addition to p53 and the pRB family members, T Ag serves to bind to and inactivate the growth-suppressing properties of CUL7. In addition, these results imply that, at least in the presence of T Ag, CUL7 may function as a tumor suppressor. PMID:16140746

  20. Looking at Earth from Space: Teacher's Guide with Activities for Earth and Space Science

    NASA Technical Reports Server (NTRS)

    Steele, Colleen (Editor); Steele, Colleen; Ryan, William F.

    1995-01-01

    The Maryland Pilot Earth Science and Technology Education Network (MAPS-NET) project was sponsored by the National Aeronautics and Space Administration (NASA) to enrich teacher preparation and classroom learning in the area of Earth system science. This publication includes a teacher's guide that replicates material taught during a graduate-level course of the project and activities developed by the teachers. The publication was developed to provide teachers with a comprehensive approach to using satellite imagery to enhance science education. The teacher's guide is divided into topical chapters and enables teachers to expand their knowledge of the atmosphere, common weather patterns, and remote sensing. Topics include: weather systems and satellite imagery including mid-latitude weather systems; wave motion and the general circulation; cyclonic disturbances and baroclinic instability; clouds; additional common weather patterns; satellite images and the internet; environmental satellites; orbits; and ground station set-up. Activities are listed by suggested grade level and include the following topics: using weather symbols; forecasting the weather; cloud families and identification; classification of cloud types through infrared Automatic Picture Transmission (APT) imagery; comparison of visible and infrared imagery; cold fronts; to ski or not to ski (imagery as a decision making tool), infrared and visible satellite images; thunderstorms; looping satellite images; hurricanes; intertropical convergence zone; and using weather satellite images to enhance a study of the Chesapeake Bay. A list of resources is also included.

  1. Green space and physical activity: An observational study using Health Survey for England data

    PubMed Central

    Mytton, Oliver T; Townsend, Nick; Rutter, Harry; Foster, Charlie

    2012-01-01

    Past studies have suggested that a link between health outcomes and green space is due to increased levels of physical activity of individuals living in areas with more green space. We found a positive association between green space and physical activity levels. The odds of achieving the recommended amount of physical activity was 1.27 (95% CI: 1.13–1.44) for people living in the greenest quintile in England compared to those living in the least green quintile, after controlling for individual and environmental factors. However, no association was found between green space and types of physical activity normally associated with green space. An association was found with other types of physical activity (gardening and do-it-yourself, and occupational physical activity). These findings suggest that although there is a positive association between physical activity and green space it may not be explained by individuals using green space for recreation. PMID:22795498

  2. Active Volcano Monitoring using a Space-based Hyperspectral Imager

    NASA Astrophysics Data System (ADS)

    Cipar, J. J.; Dunn, R.; Cooley, T.

    2010-12-01

    Active volcanoes occur on every continent, often in close proximity to heavily populated areas. While ground-based studies are essential for scientific research and disaster mitigation, remote sensing from space can provide rapid and continuous monitoring of active and potentially active volcanoes [Ramsey and Flynn, 2004]. In this paper, we report on hyperspectral measurements of Kilauea volcano, Hawaii. Hyperspectral images obtained by the US Air Force TacSat-3/ARTEMIS sensor [Lockwood et al, 2006] are used to obtain estimates of the surface temperatures for the volcano. ARTEMIS measures surface-reflected light in the visible, near-infrared, and short-wave infrared bands (VNIR-SWIR). The SWIR bands are known to be sensitive to thermal radiation [Green, 1996]. For example, images from the NASA Hyperion hyperspectral sensor have shown the extent of wildfires and active volcanoes [Young, 2009]. We employ the methodology described by Dennison et al, (2006) to obtain an estimate of the temperature of the active region of Kilauea. Both day and night-time images were used in the analysis. To improve the estimate, we aggregated neighboring pixels. The active rim of the lava lake is clearly discernable in the temperature image, with a measured temperature exceeding 1100o C. The temperature decreases markedly on the exterior of the summit crater. While a long-wave infrared (LWIR) sensor would be ideal for volcano monitoring, we have shown that the thermal state of an active volcano can be monitored using the SWIR channels of a reflective hyperspectral imager. References: Dennison, Philip E., Kraivut Charoensiri, Dar A. Roberts, Seth H. Peterson, and Robert O. Green (2006). Wildfire temperature and land cover modeling using hyperspectral data, Remote Sens. Environ., vol. 100, pp. 212-222. Green, R. O. (1996). Estimation of biomass fire temperature and areal extent from calibrated AVIRIS spectra, in Summaries of the 6th Annual JPL Airborne Earth Science Workshop, Pasadena, CA

  3. Evaluation of active thermal control options for Space Station

    NASA Technical Reports Server (NTRS)

    Schuster, J. R.; Gruszczynski, M. J.; Owen, J. W.

    1986-01-01

    An analysis of various Space Station (MSS) active thermal control systems options under consideration because of their potential low weight, efficiency and reliability is reported. The study addressed ordinary and diode-action body mounted radiators, thermal storage, the area and pumping power requirements for single-phase cooling of cold plates, and single-phase and two-phase active cooling loops. The base configuration considered was a core MSS formed by four habitable modules on which are mounted heat pipe radiators articulated to be always edge-on to the sun. A simulation was performed which accounted for the available heat sinks, several thermal loads and the heat rejection capability. No benefits were found with diode-action radiators if the solar absorption is 0.1 or less, although diode-action heat pipes will maintain a higher level of performance in the presence of coating degradation. Thermal storage becomes important only with radiator coating degradation. Water can be up to three times as efficient as Freon as a heat transfer medium. Finally, single-phase cooling offers a lower system mass than two-phase cooling if varying temperature heat loads can be accommodated.

  4. Overview of global space activities in 2007/2008

    NASA Astrophysics Data System (ADS)

    Peter, Nicolas; Delmotte, Raphaëlle

    2009-08-01

    The period ranging from July 2007 to June 2008 has been marked by significant trends and issues in the space sector, particularly under the impulsion of space-faring countries. The internationalisation and globalisation of the space sector which started a few years ago have been gaining momentum as well. As a consequence, the size of the space sector has been growing, as well as the global competition for market shares.

  5. Space weather activities at SERC for IHY: MAGDAS

    NASA Astrophysics Data System (ADS)

    Yumoto, Kiyohumi; MAGDAS Group

    2007-12-01

    We will introduce MAGDAS project of Space Environment Research Center (SERC), Kyushu University (KU) for space weather. The new MAGDAS data can be used to monitor global electromagnetic and plasma environment change in geospace, and then to bring about a better understanding of the complex and compound Sun-Earth system. The SERC also conducts daily space weather ``now casting'', to train and educate KU students, and to globally disseminate space weather information to the scientific community and the general public.

  6. Spatial Polygamy and Contextual Exposures (SPACEs): Promoting Activity Space Approaches in Research on Place and Health

    PubMed Central

    Matthews, Stephen A.; Yang, Tse-Chuan

    2014-01-01

    Exposure science has developed rapidly and there is an increasing call for greater precision in the measurement of individual exposures across space and time. Social science interest in an individual’s environmental exposure, broadly conceived, has arguably been quite limited conceptually and methodologically. Indeed, we appear to lag behind our exposure science colleagues in our theories, data, and methods. In this paper we discuss a framework based on the concept of spatial polygamy to demonstrate the need to collect new forms of data on human spatial behavior and contextual exposures across time and space. Adopting new data and methods will be essential if we want to better understand social inequality in terms of exposure to health risks and access to health resources. We discuss the opportunities and challenges focusing on the potential seemingly offered by focusing on human mobility, and specifically the utilization of activity space concepts and data. A goal of the paper is to spatialize social and health science concepts and research practice vis-a-vis the complexity of exposure. The paper concludes with some recommendations for future research focusing on theoretical and conceptual development, promoting research on new types of places and human movement, the dynamic nature of contexts, and on training. “When we elect wittingly or unwittingly, to work within a level … we tend to discern or construct – whichever emphasis you prefer – only those kinds of systems whose elements are confined to that level.”Otis Dudley Duncan (1961, p. 141). “…despite the new ranges created by improved transportation, local government units have tended to remain medieval in size.”Torsten Hägerstrand (1970, p.18) “A detective investigating a crime needs both tools and understanding. If he has no fingerprint powder, he will fail to find fingerprints on most surfaces. If he does not understand where the criminal is likely to have put his fingers, he will not

  7. Spatial Polygamy and Contextual Exposures (SPACEs): Promoting Activity Space Approaches in Research on Place and Health.

    PubMed

    Matthews, Stephen A; Yang, Tse-Chuan

    2013-08-01

    Exposure science has developed rapidly and there is an increasing call for greater precision in the measurement of individual exposures across space and time. Social science interest in an individual's environmental exposure, broadly conceived, has arguably been quite limited conceptually and methodologically. Indeed, we appear to lag behind our exposure science colleagues in our theories, data, and methods. In this paper we discuss a framework based on the concept of spatial polygamy to demonstrate the need to collect new forms of data on human spatial behavior and contextual exposures across time and space. Adopting new data and methods will be essential if we want to better understand social inequality in terms of exposure to health risks and access to health resources. We discuss the opportunities and challenges focusing on the potential seemingly offered by focusing on human mobility, and specifically the utilization of activity space concepts and data. A goal of the paper is to spatialize social and health science concepts and research practice vis-a-vis the complexity of exposure. The paper concludes with some recommendations for future research focusing on theoretical and conceptual development, promoting research on new types of places and human movement, the dynamic nature of contexts, and on training. "When we elect wittingly or unwittingly, to work within a level … we tend to discern or construct - whichever emphasis you prefer - only those kinds of systems whose elements are confined to that level."Otis Dudley Duncan (1961, p. 141)."…despite the new ranges created by improved transportation, local government units have tended to remain medieval in size."Torsten Hägerstrand (1970, p.18)"A detective investigating a crime needs both tools and understanding. If he has no fingerprint powder, he will fail to find fingerprints on most surfaces. If he does not understand where the criminal is likely to have put his fingers, he will not look in the right

  8. Utilisation of Wearable Computing for Space Programmes Test Activities Optimasation

    NASA Astrophysics Data System (ADS)

    Basso, V.; Lazzari, D.; Alemanni, M.

    2004-08-01

    New technologies are assuming a relevant importance in the Space business domain also in the Assembly Integration and Test (AIT) activities allowing process optimization and capability that were unthinkable only few years ago. This paper has the aim to describe Alenia Spazio (ALS) gained experience on the remote interaction techniques as a results of collaborations established both on European Communities (EC) initiatives, with Alenia Aeronautica (ALA) and Politecnico of Torino (POLITO). The H/W and S/W components performances increase and costs reduction due to the home computing massive utilization (especially demanded by the games business) together with the network technology possibility (offered by the web as well as the hi-speed links and the wireless communications) allow today to re-think the traditional AIT process activities in the light of the multimedia data exchange: graphical, voice video and by sure more in the future. Aerospace business confirm its innovation vocation which in the year '80 represents the cradle of the CAD systems and today is oriented to the 3D data visualization/ interaction technologies and remote visualisation/ interaction in collaborative way on a much more user friendly bases (i.e. not for specialists). Fig. 1 collects AIT extended scenario studied and adopted by ALS in these years. ALS experimented two possibilities of remote visualization/interaction: Portable [e.g. Fig.2 Personal Digital Assistant (PDA), Wearable] and walls (e.g.VR-Lab) screens as both 2D/3D visualisation and interaction devices which could support many types of traditional (mainly based on EGSE and PDM/CAD utilisation/reports) company internal AIT applications: 1. design review support 2. facility management 3. storage management 4. personnel training 5. integration sequences definition 6. assembly and test operations follow up 7. documentation review and external access to AIT activities for remote operations (e.g. tele-testing) EGSE Portable Clean room

  9. Future role and significance of space activities in reflection of global social, technological and economic trends

    NASA Astrophysics Data System (ADS)

    Diekmann, Andreas; Richarz, Hans.-Peter

    The paper describes the interrelation of space activities and global socio-economic trends like "globalisation of markets" and "renaissance of fine arts". The interrelation reveals the economic strategic, technological and scientific dimension of space activities and their benefits to mankind. Then, the significance and perspectives of space activities in these dimensions are examined in more detail. The paper calls (1) for a more visible initiative to employ space activities to tackle urgent questions of global change and development, and (2) for a stronger impetus to secure European economic position in space sector as a key industry of the 21st century.

  10. Skipping of exons by premature termination of transcription and alternative splicing within intron-5 of the sheep SCF gene: a novel splice variant.

    PubMed

    Saravanaperumal, Siva Arumugam; Pediconi, Dario; Renieri, Carlo; La Terza, Antonietta

    2012-01-01

    Stem cell factor (SCF) is a growth factor, essential for haemopoiesis, mast cell development and melanogenesis. In the hematopoietic microenvironment (HM), SCF is produced either as a membrane-bound (-) or soluble (+) forms. Skin expression of SCF stimulates melanocyte migration, proliferation, differentiation, and survival. We report for the first time, a novel mRNA splice variant of SCF from the skin of white merino sheep via cloning and sequencing. Reverse transcriptase (RT)-PCR and molecular prediction revealed two different cDNA products of SCF. Full-length cDNA libraries were enriched by the method of rapid amplification of cDNA ends (RACE-PCR). Nucleotide sequencing and molecular prediction revealed that the primary 1519 base pair (bp) cDNA encodes a precursor protein of 274 amino acids (aa), commonly known as 'soluble' isoform. In contrast, the shorter (835 and/or 725 bp) cDNA was found to be a 'novel' mRNA splice variant. It contains an open reading frame (ORF) corresponding to a truncated protein of 181 aa (vs 245 aa) with an unique C-terminus lacking the primary proteolytic segment (28 aa) right after the D(175)G site which is necessary to produce 'soluble' form of SCF. This alternative splice (AS) variant was explained by the complete nucleotide sequencing of splice junction covering exon 5-intron (5)-exon 6 (948 bp) with a premature termination codon (PTC) whereby exons 6 to 9/10 are skipped (Cassette Exon, CE 6-9/10). We also demonstrated that the Northern blot analysis at transcript level is mediated via an intron-5 splicing event. Our data refine the structure of SCF gene; clarify the presence (+) and/or absence (-) of primary proteolytic-cleavage site specific SCF splice variants. This work provides a basis for understanding the functional role and regulation of SCF in hair follicle melanogenesis in sheep beyond what was known in mice, humans and other mammals. PMID:22719917

  11. Long-Term International Space Station (ISS) Risk Reduction Activities

    NASA Astrophysics Data System (ADS)

    Fodroci, M. P.; Gafka, G. K.; Lutomski, M. G.; Maher, J. S.

    2012-01-01

    As the assembly of the ISS nears completion, it is worthwhile to step back and review some of the actions pursued by the Program in recent years to reduce risk and enhance the safety and health of ISS crewmembers, visitors, and space flight participants. While the initial ISS requirements and design were intended to provide the best practicable levels of safety, it is always possible to further reduce risk - given the determination, commitment, and resources to do so. The following is a summary of some of the steps taken by the ISS Program Manager, by our International Partners, by hardware and software designers, by operational specialists, and by safety personnel to continuously enhance the safety of the ISS, and to reduce risk to all crewmembers. While years of work went into the development of ISS requirements, there are many things associated with risk reduction in a Program like the ISS that can only be learned through actual operational experience. These risk reduction activities can be divided into roughly three categories: Areas that were initially noncompliant which have subsequently been brought into compliance or near compliance (i.e., Micrometeoroid and Orbital Debris [MMOD] protection, acoustics) Areas where initial design requirements were eventually considered inadequate and were subsequently augmented (i.e., Toxicity Hazard Level- 4 [THL] materials, emergency procedures, emergency equipment, control of drag-throughs) Areas where risks were initially underestimated, and have subsequently been addressed through additional mitigation (i.e., Extravehicular Activity [EVA] sharp edges, plasma shock hazards) Due to the hard work and cooperation of many parties working together across the span of more than a decade, the ISS is now a safer and healthier environment for our crew, in many cases exceeding the risk reduction targets inherent in the intent of the original design. It will provide a safe and stable platform for utilization and discovery for years

  12. Long-Term International Space Station (ISS) Risk Reduction Activities

    NASA Technical Reports Server (NTRS)

    Forroci, Michael P.; Gafka, George K.; Lutomski, Michael G.; Maher, Jacilyn S.

    2011-01-01

    As the assembly of the ISS nears completion, it is worthwhile to step back and review some of the actions pursued by the Program in recent years to reduce risk and enhance the safety and health of ISS crewmembers, visitors, and space flight participants. While the initial ISS requirements and design were intended to provide the best practicable levels of safety, it is always possible to further reduce risk given the determination, commitment, and resources to do so. The following is a summary of some of the steps taken by the ISS Program Manager, by our International Partners, by hardware and software designers, by operational specialists, and by safety personnel to continuously enhance the safety of the ISS, and to reduce risk to all crewmembers. While years of work went into the development of ISS requirements, there are many things associated with risk reduction in a Program like the ISS that can only be learned through actual operational experience. These risk reduction activities can be divided into roughly three categories: Areas that were initially noncompliant which have subsequently been brought into compliance or near compliance (i.e., Micrometeoroid and Orbital Debris [MMOD] protection, acoustics) Areas where initial design requirements were eventually considered inadequate and were subsequently augmented (i.e., Toxicity hazard level-4 materials, emergency procedures, emergency equipment, control of drag-throughs) Areas where risks were initially underestimated, and have subsequently been addressed through additional mitigation (i.e., Extravehicular Activity [EVA] sharp edges, plasma shock hazards). Due to the hard work and cooperation of many parties working together across the span of more than a decade, the ISS is now a safer and healthier environment for our crew, in many cases exceeding the risk reduction targets inherent in the intent of the original design. It will provide a safe and stable platform for utilization and discovery for years to come.

  13. Minimizing actuator-induced errors in active space telescope mirrors

    NASA Astrophysics Data System (ADS)

    Smith, Matthew W.; Miller, David W.

    2010-07-01

    The trend in future space telescopes points toward increased primary mirror diameter, which improves resolution and sensitivity. However, given the constraints on mass and volume deliverable to orbit by current launch vehicles, creative design solutions are needed to enable increased mirror size while keeping mass and volume within acceptable limits. Lightweight, segmented, rib-stiffened, actively controlled primary mirrors have emerged as a potential solution. Embedded surface-parallel actuators can be used to change the mirror prescription onorbit, lowering mirror mass overall by enabling lighter substrate materials such as silicon carbide (SiC) and relaxing manufacturing constraints. However, the discrete nature of the actuators causes high spatial frequency residual errors when commanding low-order prescription changes. A parameterized finite element model is used to simulate actuator-induced residual error and investigate design solutions that mitigate this error source. Judicious specification of mirror substrate geometry and actuator length is shown to reduce actuator-induced residual while keeping areal density constant. Specifically, a sinusoidally-varying rib shaping function is found to increase actuator influence functions and decrease residual. Likewise, longer actuators are found to offer reduced residual. Other options for geometric shaping are discussed, such as rib-to-facesheet blending and the use of two dimensional patch actuators.

  14. Passive and active protection from ionizing radiation in space: new activities and perspectives.

    NASA Astrophysics Data System (ADS)

    Spillantini, Piero

    Very intense Solar Cosmic Ray (SCR) events are rare, but not predictable, and can be lethal to a not protected crew in deep space. A ‘life saving’ system must therefore be provided also in short duration manned missions. Passive and active ‘life saving’ system will be revised and discussed. Galactic Cosmic Rays (GCR) instead flow continuously, have a moderate intensity but the accumulation of their effects can have consequences to human health in long duration (≥one year) mission in deep space, and a ‘health saving’ system should be provided. Passive systems are not applicable and recourse has to be made to active systems based on powerful magnetic fields for deviating particles from the habitat where crew members live and work. The activities of last decade are revised and two scenarios are evaluated and discussed: (1) magnetic toroidal systems for mitigating the radiation dose in the relatively large (≅100m3) habitat of interplanetary spaceships; (2) very large magnetic systems for protecting a large habitat (≈500m3) of an inhabited station that should operate for many decades in deep space. Effectiveness, complexity, involved engineering problems and perspectives are outlined and discussed for both the scenarios. They are nowadays studied and evaluated by a cooperative project supported by the European Union that will be illustrated in a dedicated talk.

  15. Overview of the National Aeronautics and Space Administration tether activities

    NASA Technical Reports Server (NTRS)

    Penzo, Paul A.

    1989-01-01

    NASA research concerning the use of tethers in space is reviewed, including joint research with the Italian Space Agency. Tether applications under consideration are described, such as a tethered fuel depot and a tethered gravity laboratory platform for the Space Station, providing artificial gravity to and from Mars, payload recovery and waste management, aerothermodynamic magnetospheric physics, and electrodynamic propulsion, braking, and power generation for the Space Shuttle. Also, tether flight demonstrations are examined, including the Small Expendable Deployer System, the Get-Away Tether Experiment, the Tether Elevator Crawler System, and the Kinetic Isolation Tether Experiment.

  16. Repairing the Brain by SCF+G-CSF Treatment at 6 Months Postexperimental Stroke

    PubMed Central

    Cui, Lili; Wang, Dandan; McGillis, Sandra; Kyle, Michele

    2016-01-01

    Stroke, a leading cause of adult disability in the world, is a severe medical condition with limited treatment. Physical therapy, the only treatment available for stroke rehabilitation, appears to be effective within 6 months post-stroke. Here, we have mechanistically determined the efficacy of combined two hematopoietic growth factors, stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF; SCF + G-CSF), in brain repair 6 months after cortical infarct induction in the transgenic mice carrying yellow fluorescent protein in Layer V pyramidal neurons (Thy1-YFP-H). Using a combination of live brain imaging, whole brain imaging, molecular manipulation, synaptic and vascular assessments, and motor function examination, we found that SCF + G-CSF promoted mushroom spine formation, enlarged postsynaptic membrane size, and increased postsynaptic density-95 accumulation and blood vessel density in the peri-infarct cavity cortex; and that SCF + G-CSF treatment improved motor functional recovery. The SCF + G-CSF-enhanced motor functional recovery was dependent on the synaptic and vascular regeneration in the peri-infarct cavity cortex. These data suggest that a stroke-damaged brain is repairable by SCF + G-CSF even 6 months after the lesion occurs. This study provides novel insights into the development of new restorative strategies for stroke recovery. PMID:27511907

  17. INDO/SCF-CI calculations and structural spectroscopic studies of some complexes of 4-hydroxyacetanilide

    NASA Astrophysics Data System (ADS)

    El-Shahawy, A. S.; Ahmed, S. M.; Sayed, N. Kh.

    2007-01-01

    The electronic energies among different possible structures of 4-hydroxyacetanilide (paracetamol) (PA) molecule, were calculated using INDO method and it has been concluded that its structure has C s point group symmetry of the cis-form. The ionization potential, electron affinity, dipole moment and binding energy have been calculated. The calculated electronic transitions of the cis-form of PA using SCF-CI method have good coincidence with the electronic absorption spectrum. The temperature effect on the electronic spectrum of PA confirms the presence of one conformer only. The electronic spectra of PA compound were studied in different polar- and non-polar solvents and the hydrogen bonding as well as the orientation energies of the polar solvents were determined from the mixed solvents studies. Complexes of PA with various metal ions such as, Cu(II), Zn(II) or Fe(II) ions of ratio 2:1, respectively, have been prepared and their structure has been confirmed by elemental analysis, atomic absorption spectra, IR spectra and 1H NMR spectra and finally it can be concluded that the structure of the complexes has C 2h point group symmetry in which two PA molecules are chelated to any one of the metal ions, Cu(II), Zn(II) and Fe(II) ions.

  18. The association between objectively measured physical activity and life-space mobility among older people.

    PubMed

    Tsai, L-T; Portegijs, E; Rantakokko, M; Viljanen, A; Saajanaho, M; Eronen, J; Rantanen, T

    2015-08-01

    The purpose of this cross-sectional study was to investigate the association between objectively measured physical activity and life-space mobility in community-dwelling older people. Life-space refers to the spatial area a person purposefully moves through in daily life (bedroom, home, yard, neighborhood, town, and beyond) and life-space mobility to the frequency of travel and the help needed when moving through different life-space areas. The study population comprised community-living 75- to 90-year-old people {n = 174; median age 79.7 [interquartile range (IQR) 7.1]}, participating in the accelerometer substudy of Life-Space Mobility in Old Age (LISPE) project. Step counts and activity time were measured by an accelerometer (Hookie "AM20 Activity Meter") for 7 days. Life-space mobility was assessed with Life-Space Assessment (LSA) questionnaire. Altogether, 16% had a life-space area restricted to the neighborhood when moving independently. Participants with a restricted life space were less physically active and about 70% of them had exceptionally low values in daily step counts (≤ 615 steps) and moderate activity time (≤ 6.8 min). Higher step counts and activity time correlated positively with life-space mobility. Prospective studies are needed to clarify the temporal order of low physical activity level and restriction in life-space mobility. PMID:26152855

  19. Catalytic borylation of SCF₃-functionalized arenes by rhodium(I) boryl complexes: regioselective C-H activation at the ortho-position.

    PubMed

    Kalläne, Sabrina I; Braun, Thomas

    2014-08-25

    An unprecedented reaction pathway for the borylation of SCF3-containing arenes using [Rh(Bpin)(PEt3)3] (pin=pinacolato) is reported. Catalytic processes were developed and the functionalizations proceed under mild reaction conditions. The C-H activations occur with a unique regioselectivity for the position ortho to the SCF3 group, which apparently serves as directing group. Borylated SCF3 compounds can serve as versatile building blocks. PMID:25088814

  20. Space Weather Activities of IONOLAB Group: IONOLAB-TEC

    NASA Astrophysics Data System (ADS)

    Arikan, F.; Sezen, U.; Arikan, O.; Ugurlu, O.; Nayir, H.

    2009-04-01

    Space Weather (SW) is the concept of changing environmental conditions in outer space and affect Earth and its technological systems. SW is a consequence of the solar activities and the coupling of solar energy on Earth's atmosphere due to the Earth's magnetic field. The monitoring and prediction of SW has utmost importance for HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere. Ionosphere is the plasma layer of the atmosphere that is ionized by solar radiation and it is a key player of SW. Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. IONOLAB is a group of researchers of various disciplines, getting together to handle challenges of the Earth's ionosphere. The team has researchers from Hacettepe University and Bilkent University, Department of Electrical and Electronics Engineering and General Command of Mapping of Turkish Army. One of the most important contributions of IONOLAB group is the automated web-based computation service for Total Electron Content (TEC). TEC corresponds to the line integral of electron density distribution on a given path. TEC can also be expressed as the amount of free electrons within 1 m2 cross-sectional area of the cylinder on the ray path. Global Position System (GPS) provides a cost-effective medium for monitoring of ionosphere using the signals recorded by stationary GPS receivers in estimating TEC. IONOLAB group has developed IONOLAB-TEC for reliable and robust estimates for all latitudes and both calm and disturbed days by using RINEX, IONEX and satellite ephemeris data provided from the IGS centers. IONOLAB-TEC consists of a regularized signal estimation algorithm which combines signals from all GPS satellites for a given instant and a given receiver, for a desired time period or for 24 hours

  1. Planetary Data Archiving Activities in Indian Space Research Organisation (isro)

    NASA Astrophysics Data System (ADS)

    Gopala Krishna, Barla; Srivastava, Pradeep Kumar

    The Indian Space Research Organisation (ISRO) has launched its first planetary mission to Moon viz., Chandrayaan-1 on October 22, 2008. The basic objectives of the Chandrayaan-1 mission are photoselenological and chemical mapping of the Moon with improved spatial and spectral resolution. The payloads in this mission are: (i) Terrain mapping stereo camera (TMC) with 20km swath (400-900 nm band) for 3D imaging of lunar surface at a spatial resolution of 5m (ii) Hyper Spectral Imager (HySI) in the 400-920 nm band with 64 channels and spatial resolution of 80m (20km swath) for mineralogical mapping (iii) High-energy X-ray (30-270 keV) spectrometer having a footprint of 40km for study of volatile transport on Moon and (iv) Laser ranging instrument with vertical resolution of 5m (v) Miniature imaging radar instrument (Mini-SAR) from APL, NASA to look for presence of ice in the polar region (vi) Near infrared spectrometer (SIR-2) from Max Plank Institute, Germany (vii)Moon Mineralogy Mapper (M3) from JPL, NASA for mineralogical mapping in the infra-red regions (0.7 -3.0 micron) (viii) Sub-keV Atom Reflecting Analyzer (SARA) from Sweden, India and Japan for detection of low energy neutral atoms emanated from the lunar surface (ix) Radiation Dose Monitor (RADOM) from Bulgaria for monitoring energetic particle flux in the lunar environment and (x) Collimated low energy (1-10keV) X-ray spectrometer (C1XS) with a field of view of 20km for chemical mapping of the lunar surface from RAL, UK. A wealth of data has been collected (November 2008 to August 2009) from the above instru-ments during the mission life of Chandrayaan-1 and the science data from these instruments is being archived at Indian Space Science Data Centre (ISSDC). ISRO Science Data Archive (ISDA) identified at ISSDC is the primary data archive for the payload data of current and future Indian space science missions. The data center (ISSDC) is responsible for the Ingest, Archive, and Dissemination of the payload

  2. A Highly Triflated Rare-Earth Ion in [Eu(O3SCF3)8](5-).

    PubMed

    Bruns, Jörn; Krüger, Sascha; Adlung, Matthias; Wickleder, Claudia; Niehaus, Oliver; Pöttgen, Rainer; Klüner, Thorsten; Kräuter, Jessica; Wickleder, Mathias S

    2015-08-24

    The reaction of Eu2O3 with fuming nitric acid, trifluormethanesulfonic acid, and its anhydride in torch-sealed glass ampoules at 120 °C gave the europium compound (NO)5[Eu(O3SCF3)8] (orthorhombic, Fddd, Z = 16, a = 1932.69(4), b = 2878.44(7), c = 2955.12(7) pm, V = 16439.7(7) Å(3)). The compound exhibits the [Eu(O3SCF3)8](5-) anion showing for the first time a lanthanide ion that is exclusively coordinated by eight triflate anions. The anion has been further investigated by DFT calculations, which also allowed clear assignment of the vibrational spectra. Moreover, magnetochemical and luminescence measurements gave additional insight into the properties of this complex. The luminescence spectra revealed that the Eu(3+) ions are in a pseudo D4d symmetric environment. PMID:26179376

  3. Medical operations and life sciences activities on space station

    NASA Technical Reports Server (NTRS)

    Johnson, P. C. (Editor); Mason, J. A. (Editor)

    1982-01-01

    Space station health maintenance facilities, habitability, personnel, and research in the medical sciences and in biology are discussed. It is assumed that the space station structure will consist of several modules, each being consistent with Orbiter payload bay limits in size, weight, and center of gravity.

  4. Aeronautics and Space Report of the President: 1977 Activities.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    The national programs in aeronautics and space made steady progress in 1977 toward their long-term objectives. In aeronautics the goals were improved performance, energy efficiency, and safety in aircraft. In space the goals were: (1) better remote sensing systems to generate more sophisticated information about the Earth's environment; (2)…

  5. Public open space, physical activity, urban design and public health: Concepts, methods and research agenda.

    PubMed

    Koohsari, Mohammad Javad; Mavoa, Suzanne; Villanueva, Karen; Sugiyama, Takemi; Badland, Hannah; Kaczynski, Andrew T; Owen, Neville; Giles-Corti, Billie

    2015-05-01

    Public open spaces such as parks and green spaces are key built environment elements within neighbourhoods for encouraging a variety of physical activity behaviours. Over the past decade, there has been a burgeoning number of active living research studies examining the influence of public open space on physical activity. However, the evidence shows mixed associations between different aspects of public open space (e.g., proximity, size, quality) and physical activity. These inconsistencies hinder the development of specific evidence-based guidelines for urban designers and policy-makers for (re)designing public open space to encourage physical activity. This paper aims to move this research agenda forward, by identifying key conceptual and methodological issues that may contribute to inconsistencies in research examining relations between public open space and physical activity. PMID:25779691

  6. Climate Change Adaptation Science Activities at NASA Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Stefanov, William L.; Lulla, Kamlesh

    2012-01-01

    The Johnson Space Center (JSC), located in the southeast metropolitan region of Houston, TX is the prime NASA center for human spaceflight operations and astronaut training, but it also houses the unique collection of returned extraterrestrial samples, including lunar samples from the Apollo missions. The Center's location adjacent to Clear Lake and the Clear Creek watershed, an estuary of Galveston Bay, puts it at direct annual risk from hurricanes, but also from a number of other climate-related hazards including drought, floods, sea level rise, heat waves, and high wind events all assigned Threat Levels of 2 or 3 in the most recent NASA Center Disaster/Risk Matrix produced by the Climate Adaptation Science Investigator Working Group. Based on prior CASI workshops at other NASA centers, it is recognized that JSC is highly vulnerable to climate-change related hazards and has a need for adaptation strategies. We will present an overview of prior CASI-related work at JSC, including publication of a climate change and adaptation informational data brochure, and a Resilience and Adaptation to Climate Risks Workshop that was held at JSC in early March 2012. Major outcomes of that workshop that form a basis for work going forward are 1) a realization that JSC is embedded in a regional environmental and social context, and that potential climate change effects and adaptation strategies will not, and should not, be constrained by the Center fence line; 2) a desire to coordinate data collection and adaptation planning activities with interested stakeholders to form a regional climate change adaptation center that could facilitate interaction with CASI; 3) recognition that there is a wide array of basic data (remotely sensed, in situ, GIS/mapping, and historical) available through JSC and other stakeholders, but this data is not yet centrally accessible for planning purposes.

  7. Structural Basis of the Cks1-Dependent Recognition of P27Kip1 by the SCF skp2 Ubiquitin Ligase

    SciTech Connect

    Hao,B.; Zheng, N.; Schulman, B.; Wu, G.; Miller, J.; Pagano, M.; Pavletich, N.

    2005-01-01

    The ubiquitin-mediated proteolysis of the Cdk2 inhibitor p27(Kip1) plays a central role in cell cycle progression, and enhanced degradation of p27(Kip1) is associated with many common cancers. Proteolysis of p27(Kip1) is triggered by Thr187 phosphorylation, which leads to the binding of the SCF(Skp2) (Skp1-Cul1-Rbx1-Skp2) ubiquitin ligase complex. Unlike other known SCF substrates, p27(Kip1) ubiquitination also requires the accessory protein Cks1. The crystal structure of the Skp1-Skp2-Cks1 complex bound to a p27(Kip1) phosphopeptide shows that Cks1 binds to the leucine-rich repeat (LRR) domain and C-terminal tail of Skp2, whereas p27(Kip1) binds to both Cks1 and Skp2. The phosphorylated Thr187 side chain of p27(Kip1) is recognized by a Cks1 phosphate binding site, whereas the side chain of an invariant Glu185 inserts into the interface between Skp2 and Cks1, interacting with both. The structure and biochemical data support the proposed model that Cdk2-cyclin A contributes to the recruitment of p27(Kip1) to the SCF(Skp2)-Cks1 complex.

  8. Destination state screening of active spaces in spin dynamics simulations

    NASA Astrophysics Data System (ADS)

    Krzystyniak, M.; Edwards, Luke J.; Kuprov, Ilya

    2011-06-01

    We propose a novel avenue for state space reduction in time domain Liouville space spin dynamics simulations, using detectability as a selection criterion - only those states that evolve into or affect other detectable states are kept in the simulation. This basis reduction procedure (referred to as destination state screening) is formally exact and can be applied on top of the existing state space restriction techniques. As demonstrated below, in many cases this results in further reduction of matrix dimension, leading to considerable acceleration of many spin dynamics simulation types. Destination state screening is implemented in the latest version of the Spinach library (http://spindynamics.org).

  9. Advanced planning activity. [for interplanetary flight and space exploration

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Selected mission concepts for interplanetary exploration through 1985 were examined, including: (1) Jupiter orbiter performance characteristics; (2) solar electric propulsion missions to Mercury, Venus, Neptune, and Uranus; (3) space shuttle planetary missions; (4) Pioneer entry probes to Saturn and Uranus; (5) rendezvous with Comet Kohoutek and Comet Encke; (6) space tug capabilities; and (7) a Pioneer mission to Mars in 1979. Mission options, limitations, and performance predictions are assessed, along with probable configurational, boost, and propulsion requirements.

  10. Differences in associations between active transportation and built environmental exposures when expressed using different components of individual activity spaces.

    PubMed

    van Heeswijck, Torbjorn; Paquet, Catherine; Kestens, Yan; Thierry, Benoit; Morency, Catherine; Daniel, Mark

    2015-05-01

    This study assessed relationships between built environmental exposures measured within components of individual activity spaces (i.e., travel origins, destinations and paths in-between), and use of active transportation in a metropolitan setting. Individuals (n=37,165) were categorised as using active or sedentary transportation based on travel survey data. Generalised Estimating Equations analysis was used to test relationships with active transportation. Strength and significance of relationships between exposures and active transportation varied for different components of the activity space. Associations were strongest when including travel paths in expression of the built environment. Land use mix and greenness were negatively related to active transportation. PMID:25862996

  11. Activities of the Japanese space weather forecast center at Communications Research Laboratory.

    PubMed

    Watari, Shinichi; Tomita, Fumihiko

    2002-12-01

    The International Space Environment Service (ISES) is an international organization for space weather forecasts and belongs to the International Union of Radio Science (URSI). There are eleven ISES forecast centers in the world, and Communications Research Laboratory (CRL) runs the Japanese one. We make forecasts on the space environment and deliver them over the phones and through the Internet. Our forecasts could be useful for human activities in space. Currently solar activity is near maximum phase of the solar cycle 23. We report the several large disturbances of space environment occurred in 2001, during which low-latitude auroras were observed several times in Japan. PMID:12793730

  12. New Insights into the Negative Thermal Expansion: Direct Experimental Evidence for the "Guitar-String" Effect in Cubic ScF3.

    PubMed

    Hu, Lei; Chen, Jun; Sanson, Andrea; Wu, Hui; Guglieri Rodriguez, Clara; Olivi, Luca; Ren, Yang; Fan, Longlong; Deng, Jinxia; Xing, Xianran

    2016-07-13

    The understanding of the negative thermal expansion (NTE) mechanism remains challenging but critical for the development of NTE materials. This study sheds light on NTE of ScF3, one of the most outstanding materials with NTE. The local dynamics of ScF3 has been investigated by a combined analysis of synchrotron-based X-ray total scattering, extended X-ray absorption fine structure, and neutron powder diffraction. Very interestingly, we observe that (i) the Sc-F nearest-neighbor distance strongly expands with increasing temperature, while the Sc-Sc next-nearest-neighbor distance contracts, (ii) the thermal ellipsoids of relative vibrations between Sc-F nearest-neighbors are highly elongated in the direction perpendicular to the Sc-F bond, indicating that the Sc-F bond is much softer to bend than to stretch, and (iii) there is mainly dynamically transverse motion of fluorine atoms, rather than static shifts. These results are direct experimental evidence for the NTE mechanism, in which the rigid unit is not necessary for the occurrence of NTE, and the key role is played by the transverse thermal vibrations of fluorine atoms through the "guitar-string" effect. PMID:27336200

  13. Activities of the Space Studies Board of the National Research Council

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This 1993 annual report of the Space Studies Board of the National Research Council chronicles the activities of the board during a year filled with questioning and change in the country's civil space program. The brief accounts contained herein of the activities of the board and of its committees, together with summaries of two major reports and the complete texts of three letter reports, sketch out major space research issues that faced the nation's space scientists and engineers during the year, including scientific prerequisites for the human exploration of space, improving NASA's technology for space science, the space station and prerequisites for the human exploration program, several issues in the space life sciences, and the Advanced X-ray Astrophysics Facility.

  14. Aeronautics and Space Report of the President: Fiscal Year 1998 Activities

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year. In recent years, the reports have been prepared on a fiscal year (FY) basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 1997, through September 30, 1998. The activities of agencies included are NASA, the Department of Defense, The Federal Aviation Administration, the Department of Commerce, the Department of the Interior, the Federal Communications Commission, the Department of Agriculture, the National Science Foundation, the Department of State, the Department of Energy, the Smithsonian Institution, the Arms Control and Disarmament Agency, the Environmental Protection Agency, and the U.S. Information Agency. Appendices cover the U.S. Government Spacecraft Record, World Record of Space Launches Successful in Attaining Earth Orbit or Beyond , Successful Launches to Orbit on U.S. Launch Vehicles, October 1, 1997-September 30, 1998, U.S. and Russian Human Space Flights, 1961-September 30, 1998, U.S. Space Launch Vehicles, Space Activities of the U.S. Government-Historical Budget Summary, Space Activities of the U.S. Government-Budget Authority in Equivalent FY 1998 Dollars, Federal Space Activities Budget, Federal Aeronautics Budget, and a glossary

  15. Configuration studies for active electrostatic space radiation shielding

    NASA Astrophysics Data System (ADS)

    Joshi, Ravindra P.; Qiu, Hao; Tripathi, Ram K.

    2013-07-01

    Developing successful and optimal solutions to mitigating the hazards of severe space radiation in deep space long duration missions is critical for the success of deep-space explorations. Space crews traveling aboard interplanetary spacecraft will be exposed to a constant flux of galactic cosmic rays (GCR), as well as intense fluxes of charged particles during solar particle events (SPEs). A recent report (Tripathi et al., Adv. Space Res. 42 (2008) 1043-1049), had explored the feasibility of using electrostatic shielding in concert with the state-of-the-art materials shielding technologies. Here we continue to extend the electrostatic shielding strategy and quantitatively examine a different configuration based on multiple toroidal rings. Our results show that SPE radiation can almost be eliminated by these electrostatic configurations. Also, penetration probabilities for novel structures such as toroidal rings are shown to be substantially reduced as compared to the simpler all-sphere geometries. More interestingly, the dimensions and aspect ratio of the toroidal rings could be altered and optimized to achieve an even higher degree of radiation protection.

  16. Conceptualizing and Comparing Neighborhood and Activity Space Measures for Food Environment Research

    PubMed Central

    Crawford, Thomas W.; Pitts, Stephanie B. Jilcott; McGuirt, Jared T.; Keyserling, Thomas C.; Ammerman, Alice S.

    2014-01-01

    Greater accessibility to geospatial technologies has led to a surge of spatialized public health research, much of which has focused on food environments. The purpose of this study was to analyze differing spatial measures of exposure to supermarkets and farmers’ markets among women of reproductive age in eastern North Carolina. Exposure measures were derived using participant-defined neighborhoods, investigator-defined road network neighborhoods, and activity spaces incorporating participants’ time space behaviors. Results showed that mean area for participant-defined neighborhoods (0.04 sq. miles) was much smaller than 2.0 mile road network neighborhoods (3.11 sq. miles) and activity spaces (26.36 sq. miles), and that activity spaces provided the greatest market exposure. The traditional residential neighborhood concept may not be particularly relevant for all places. Time-space approaches capturing activity space may be more relevant, particularly if integrated with mixed methods strategies. PMID:25306420

  17. The generalized active space concept in multiconfigurational self-consistent field methods.

    PubMed

    Ma, Dongxia; Li Manni, Giovanni; Gagliardi, Laura

    2011-07-28

    A multiconfigurational self-consistent field method based on the concept of generalized active space (GAS) is presented. GAS wave functions are obtained by defining an arbitrary number of active spaces with arbitrary occupation constraints. By a suitable choice of the GAS spaces, numerous ineffective configurations present in a large complete active space (CAS) can be removed, while keeping the important ones in the CI space. As a consequence, the GAS self-consistent field approach retains the accuracy of the CAS self-consistent field (CASSCF) ansatz and, at the same time, can deal with larger active spaces, which would be unaffordable at the CASSCF level. Test calculations on the Gd atom, Gd(2) molecule, and oxoMn(salen) complex are presented. They show that GAS wave functions achieve the same accuracy as CAS wave functions on systems that would be prohibitive at the CAS level. PMID:21806111

  18. Standardization by ISO to Ensure the Sustainability of Space Activities

    NASA Astrophysics Data System (ADS)

    Kato, A.; Lazare, B.; Oltrogge, D.; Stokes, H.

    2013-08-01

    The ISO / Technical Committee 20 / Sub-committee 14 develops debris-related standards and technical reports to mitigate debris and help ensure mission and space sustainability. While UN Guidelines and the IADC Guidelines encourage national governments and agencies to promote debris mitigation design and operation, the ISO standards will help the global space industry promote and sustain its space-related business. In this paper the scope and status of each ISO standard is discussed within an overall framework. A comparison with international guidelines is also provided to demonstrate the level of consistency. Finally, as a case study, the ISO standards are applied to a CubeSat mission, thus demonstrating their usability on a relatively recent and popular class of satellite.

  19. Youth Initiatives and Projects on Human Rights and Ethics in Space Activities

    NASA Astrophysics Data System (ADS)

    Marshall, W.; Delegates, Sgs

    2002-01-01

    The `Declaration of Human Rights in Outer Space' project was initiated at the Space Generation Forum (SGF), at UNISPACE-III in 1999. These projects are being further developed at the Space Generation Summit (SGS), an event at World Space Congress (WSC) that will unite international students and young professionals to develop a youth vision and strategy for the peaceful uses of space. SGS, endorsed by the United Nations, will take place from October 11- 13th, during which the 200 delegates will discuss ongoing youth space activities, particularly those stemming from the UNISPACE-III/SGF and taken forward by the Space Generation Advisory Council. Delegates will address a variety of topics with the goal of devising new recommendations according to the theme, 'Accelerating Our Pace in Space'. The material presented here and in other technical sessions throughout WSC includes the findings of these discussions. In this paper, we present the work of the SGS delegates relating to ethical issues arising in space activities, and we discuss plans to organize a space ethics conference. This international and inter-generational event would aim to develop a vision and series of recommendations for how the space sector should proceed with regard to ethical issues. We present also the results of the Space Generation Summit with regards to initiating a declaration of human rights in space.

  20. Looking at Earth from Space: Teacher's Guide with Activities for Earth and Space Science.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    The Maryland Pilot Earth Science and Technology Education Network (MAPS-NET) project was sponsored by the National Aeronautics and Space Administration (NASA) to enrich teacher preparation and classroom learning in the area of Earth system science. This publication includes a teacher's guide that replicates material taught during a graduate-level…

  1. Space Resources for Teachers, Space Science, A Guide Outlining Understandings, Fundamental Concepts, and Activities.

    ERIC Educational Resources Information Center

    Thompson, Malcolm

    This instructional and resource guide is designed so that it may be used in the secondary school or in the first two years of college to present a series of units in space science, or to supplement existing science and mathematics courses. The guide consists of six units: (1) measurement, distance, and size in astronomy, (2) atoms, spectra, and…

  2. Space research activities during missions of the past

    NASA Technical Reports Server (NTRS)

    Frey, M. A.

    1996-01-01

    For over 30 yr, men and women have lived for various periods of time in a weightless (or free-fall) environment while orbiting the Earth. During these years, we have learned that humans function quite well for short periods of weightlessness, that is, for up to a little more than a year. Some space flight missions have provided physiologic data, including cardiovascular data, from the spacefarers. In fact, some missions have provided laboratories for systematic study of cardiovascular responses and adaptation to space flight. However, the opportunity to obtain physiologic data from people in space is a rarity. It is important to remember that the population sample sizes are small, other stresses may confound the effects of weightlessness, and in some situations the crewmembers are subjects for several experiments at the same time. Furthermore, comparison of cardiovascular data from space flight to data obtained on the ground is sometimes difficult because the subject's posture on the ground is not always reported; in a gravity environment, posture influences the hydrostatic gradient. This over view describes what we have learned about cardiovascular function during flight and after return to Earth.

  3. Active control of large space structures: An introduction and overview

    NASA Technical Reports Server (NTRS)

    Doane, G. B., III; Tollison, D. K.; Waites, H. B.

    1985-01-01

    An overview of the large space structure (LSS) control system design problem is presented. The LSS is defined as a class of system, and LSS modeling techniques are discussed. Model truncation, control system objectives, current control law design techniques, and particular problem areas are discussed.

  4. Activity of Science and Operational Research of NICT Space Weather

    NASA Astrophysics Data System (ADS)

    Ishii, Mamoru; Nagatsuma, Tsutomu; Watari, Shinichi; Shinagawa, Hiroyuki; Tsugawa, Takuya; Kubo, Yuki

    Operational space weather forecast is for contribution to social infrastructure than for academic interests. These user need will determine the target of research, e.g., the precision level, spatial and temporal resolution and/or required lead time. We, NICT, aim two target in the present mid-term strategic plan, which are (1) forecast of ionospheric disturbance influencing to satellite positioning, and (2) forecast of disturbance in radiation belt influencing to satellite operation. We have our own observation network and develop empirical and numerical models for achieving each target. However in actual situation, it is much difficult to know the user needs quantitatively. Most of space weather phenomena makes the performance of social infrastructure poor, for example disconnect of HF communication, increase of GNSS error. Most of organizations related to these operation are negative to open these information. We have personal interviews to solve this issue. In this interview, we try to collect incident information related to space weather in each field, and to retrieve which space weather information is necessary for users. In this presentation we will introduce our research and corresponding new service, in addition to our recent scientific results.

  5. 14 CFR § 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. § 1266... exploration activities unrelated to the International Space Station. (a) The purpose of this section is to... exploration activities that are not related to the International Space Station (ISS) but involve a launch....

  6. Does activity space size influence physical activity levels of adolescents?—A GPS study of an urban environment

    PubMed Central

    Lee, Nolan C.; Voss, Christine; Frazer, Amanda D.; Hirsch, Jana A.; McKay, Heather A.; Winters, Meghan

    2015-01-01

    Background Physical activity (PA) is closely linked with child and youth health, and active travel may be a solution to enhancing PA levels. Activity spaces depict the geographic coverage of one's travel. Little is known about activity spaces and PA in adolescents. Objective To explore the relation between adolescent travel (using a spatial measure of activity space size) and daily moderate-to-vigorous PA (MVPA), with a focus on school days. Methods We used Global Positioning Systems to manually identify trips and generate activity spaces for each person-day; quantified by area for 39 students (13.8 ± 0.6 years, 38% female) attending high school in urban Downtown Vancouver, Canada. We assessed the association between activity space area and MVPA using multi-level regression. We calculated total, school-day and trip-based MVPA for each valid person-day (accelerometry; ≥ 600 min wear time). Results On school days, students accrued 68.2 min/day (95% CI 60.4–76.0) of MVPA. Daily activity spaces averaged 2.2 km2 (95% CI 1.3–3.0). There was no association between activity space size and school-day MVPA. Students accrued 21.8 min/day (95% CI 19.2–24.4) of MVPA during school hours, 19.4 min/day (95% CI 15.1–23.7) during travel, and 28.3 min/day (95% CI 22.3–34.3) elsewhere. Conclusion School and school travel are important sources of PA in Vancouver adolescents, irrespective of activity space area covered. PMID:26807349

  7. Russian Activities in Space Photovoltaic Power Modules with Concentrators

    NASA Technical Reports Server (NTRS)

    Andreev, Vyacheslav M.; Rumyantsev, Valeri D.

    2004-01-01

    Space concentrator modules with point-and line-focus Fresnel lenses and with reflective parabolic troughs have been developed recently at Ioffe Physico-Technical Institute. PV receivers for these modules are based: on the single junction LPE and MOCVD AlGaAs/GaAs solar cells characterized by AM0 efficiencies of 23.5 - 24% at 20 - 50 suns and 24 - 24.75 at 50 - 200 suns; on the mechanically stacked tandem AlGaAs/GaAs-GaSb cells with efficiency of 27 - 28 at 20 - 100 suns. MOCVD AlGaAs/GaAs cells with internal Bragg reflector have shown a higher radiation resistance as compared to a traditional structure. Monolithic two-terminal tandems AlGaAs (top)-GaAs (bottom) for space application and GaSb (top) - InGaAsSb (bottom) for TRV application are under development as well.

  8. Report on Advanced Life Support Activities at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.

    2004-01-01

    Plant studies at Kennedy Space Center last year focused on selecting cultivars of lettuce, tomato, and pepper for further testing as crops for near-term space flight applications. Other testing continued with lettuce, onion, and radish plants grown at different combinations of light (PPF), temperature, and CO2 concentration. In addition, comparisons of mixed versus mono culture approaches for vegetable production were studied. Water processing testing focused on the development and testing of a rotating membrane bioreactor to increase oxygen diffusion levels for reducing total organic carbon levels and promoting nitrification. Other testing continued to study composting testing for food wastes (NRA grant) and the use of supplemental green light with red/blue LED lighting systems for plant production (NRC fellowship).

  9. Development of a novel electron source for active space experiments

    NASA Astrophysics Data System (ADS)

    Everding, Daniel

    2013-01-01

    Recent advances in light emitting diode (LED) technology have facilitated a potential remedy to the problems plaguing filament based electron sources. Using spaceworthy LEDs, the photoelectron cathode and its progenitor the ultraviolet cathode (UVC) take advantage of the photoelectric effect to produce electrons for space based experiments. To produce these devices, two species of LED, each producing either ultraviolet or visible radiation, were collected and tested to determine potential photocurrent output. Additionally, materials with requisite photoemission characteristics were collected and tested in vacuum with the LEDs to assess their usefulness as photoelectron sources. Furthermore, circuitry and computer software was compiled, tested, and refined to control the experimental and custodial duties of the UVC and photoelectron cathode while deployed as an electron source in space.

  10. Recent and Future Stratospheric Balloon Activities at Esrange Space Center

    NASA Astrophysics Data System (ADS)

    Kemi, Stig

    Esrange Space Center located in northern Sweden has during 45 years been a leading launch site for both sounding rockets and stratospheric balloons. We have a unique combination of maintaining both stratospheric balloons and sounding rockets launch operations. Most balloon flights are normally handled inside Scandinavia but since 2005 PersonNamesemi-circular flights are performed with recovery in northern Canada. The Swedish Government and Swedish National Space Board are now finaliz-ing an agreement with Russia for peaceful uPersonNamese of space, which will permit circumpolar balloon flights. Within this agreement we will soon be able to of-fer the science community long duration balloon flights with durations for PersonNameseveral weeks. The balloon operations at Esrange Space Center are yearly expanding. Both NASA and CNES have long term plans for balloon flights from northern Sweden. We have also received a request from JAXA for future balloon missions. To handle balloon campaigns with large numbers of payloads or build up for two different campaigns a new big assembly hall will be ready for use at the beginning of 2011. January 24 we made an historical balloon flight in a very cold stratosphere with a Zodiac metricconverterProductID402?000 m3402ü ınbsp;000 m3402 000 m3 balloon carrying a 750kg gondola with the German Mipas-B/Telis instrument. The balloon reached 34kms alti-tude after a carefully piloted ascent in temperature levels down to -89 degrees Centigrade. The scientists received unique data during the 13 hours and 30 minutes long sailing at different altitudes during slow descent. The payload was recovered in very good condition 80 kms from the border between country-regionFinland and Russia.

  11. Mathematical analysis techniques for modeling the space network activities

    NASA Technical Reports Server (NTRS)

    Foster, Lisa M.

    1992-01-01

    The objective of the present work was to explore and identify mathematical analysis techniques, and in particular, the use of linear programming. This topic was then applied to the Tracking and Data Relay Satellite System (TDRSS) in order to understand the space network better. Finally, a small scale version of the system was modeled, variables were identified, data was gathered, and comparisons were made between actual and theoretical data.

  12. Aerospace Battery Activities at NASA/Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rao, Gopalakrishna M.

    2006-01-01

    Goddard Space Flight Center has "pioneered" rechargeable secondary battery design, test, infusion and in-orbit battery management among NASA installations. Nickel cadmium batteries of various designs and sizes have been infused for LEO, GEO and Libration Point spacecraft. Nickel-Hydrogen batteries have currently been baselined for the majority of our missions. Li-Ion batteries from ABSL, JSB, SaFT and Lithion have been designed and tested for aerospace application.

  13. Active space debris removal by using laser propulsion

    NASA Astrophysics Data System (ADS)

    Rezunkov, Yu. A.

    2013-03-01

    At present, a few projects on the space debris removal by using highpower lasers are developed. One of the established projects is the ORION proposed by Claude Phipps from Photonics Associates Company and supported by NASA (USA) [1]. But the technical feasibility of the concept is limited by sizes of the debris objects (from 1 to 10 cm) because of a small thrust impulse generated at the laser ablation of the debris materials. At the same time, the removal of rocket upper stages and satellites, which have reached the end of their lives, has been carried out only in a very small number of cases and most of them remain on the Low Earth Orbits (LEO). To reduce the amount of these large-size objects, designing of space systems allowing deorbiting upper rocket stages and removing large-size satellite remnants from economically and scientifically useful orbits to disposal ones is considered. The suggested system is based on high-power laser propulsion. Laser-Orbital Transfer Vehicle (LOTV) with the developed aerospace laser propulsion engine is considered as applied to the problem of mitigation of man-made large-size space debris in LEO.

  14. Genetically engineered mouse models for functional studies of SKP1-CUL1-F-box-protein (SCF) E3 ubiquitin ligases

    PubMed Central

    Zhou, Weihua; Wei, Wenyi; Sun, Yi

    2013-01-01

    The SCF (SKP1 (S-phase-kinase-associated protein 1), Cullin-1, F-box protein) E3 ubiquitin ligases, the founding member of Cullin-RING ligases (CRLs), are the largest family of E3 ubiquitin ligases in mammals. Each individual SCF E3 ligase consists of one adaptor protein SKP1, one scaffold protein cullin-1 (the first family member of the eight cullins), one F-box protein out of 69 family members, and one out of two RING (Really Interesting New Gene) family proteins RBX1/ROC1 or RBX2/ROC2/SAG/RNF7. Various combinations of these four components construct a large number of SCF E3s that promote the degradation of many key regulatory proteins in cell-context, temporally, and spatially dependent manners, thus controlling precisely numerous important cellular processes, including cell cycle progression, apoptosis, gene transcription, signal transduction, DNA replication, maintenance of genome integrity, and tumorigenesis. To understand how the SCF E3 ligases regulate these cellular processes and embryonic development under in vivo physiological conditions, a number of mouse models with transgenic (Tg) expression or targeted deletion of components of SCF have been established and characterized. In this review, we will provide a brief introduction to the ubiquitin-proteasome system (UPS) and the SCF E3 ubiquitin ligases, followed by a comprehensive overview on the existing Tg and knockout (KO) mouse models of the SCF E3s, and discuss the role of each component in mouse embryogenesis, cell proliferation, apoptosis, carcinogenesis, as well as other pathogenic processes associated with human diseases. We will end with a brief discussion on the future directions of this research area and the potential applications of the knowledge gained to more effective therapeutic interventions of human diseases. PMID:23528706

  15. Cortical activity in the null space: permitting preparation without movement

    PubMed Central

    Kaufman, Matthew T.; Churchland, Mark M.; Ryu, Stephen I.; Shenoy, Krishna V.

    2014-01-01

    Neural circuits must perform computations and then selectively output the results to other circuits. Yet synapses do not change radically at millisecond timescales. A key question then is: how is communication between neural circuits controlled? In motor control, brain areas directly involved in driving movement are active well before movement begins. Muscle activity is some readout of neural activity, yet remains largely unchanged during preparation. Here we find that during preparation, while the monkey holds still, changes in motor cortical activity cancel out at the level of these population readouts. Motor cortex can thereby prepare the movement without prematurely causing it. Further, we found evidence that this mechanism also operates in dorsal premotor cortex (PMd), largely accounting for how preparatory activity is attenuated in primary motor cortex (M1). Selective use of “output-null” vs. “output-potent” patterns of activity may thus help control communication to the muscles and between these brain areas. PMID:24487233

  16. A poly-epoxy surface explored by Hartree-Fock ΔSCF simulations of C1s XPS spectra.

    PubMed

    Gavrielides, A; Duguet, T; Esvan, J; Lacaze-Dufaure, C; Bagus, P S

    2016-08-21

    Whereas poly-epoxy polymers represent a class of materials with a wide range of applications, the structural disorder makes them difficult to model. In the present work, we use good experimental model samples in the sense that they are pure, fully polymerized, flat and smooth, defect-free, and suitable for ultrahigh vacuum x-ray photoelectron spectroscopy, XPS, experiments. In parallel, we perform Hartree-Fock, HF, calculations of the binding energies, BEs, of the C1s electrons in a model molecule composed of the two constituents of the poly-epoxy sample. These C1s BEs were determined using the HF ΔSCF method, which is known to yield accurate values, especially for the shifts of the BEs, ΔBEs. We demonstrate the benefits of combining rigorous theory with careful XPS measurements in order to obtain correct assignments of the C1s XPS spectra of the polymer sample. Both the relative binding energies-by the ΔSCF method-and relative intensities-in the sudden approximation, SA, are calculated. It results in an excellent match with the experimental spectra. We are able to identify 9 different chemical environments under the C1s peak, where an exclusively experimental work would have found only 3 contributions. In addition, we observe that some contributions are localized at discrete binding energies, whereas others allow a much wider range because of the variation of their second neighbor bound polarization. Therefore, HF-ΔSCF simulations significantly increase the spectral resolution of XPS and thus offer a new avenue for the exploration of the surface of polymers. PMID:27544119

  17. Application of the French Space Operation Act and the Development of Space Activities in the Field of Launchers

    NASA Astrophysics Data System (ADS)

    Cahuzac, F.; Biard, A.

    2012-01-01

    The development of space activities has led France to define a new legal framework: French Space Operation Act (FSOA). The aim of this act, is to define the conditions according to which the French government authorizes and checks the spatial operations under its jurisdiction or its international responsibility as State of launch, according to the international treaties of the UN on space, in particular the Treaty (1967) on Principles Governing the Activities of States in the Exploration and Use of Outer Space, the Convention ( 1972 ) on International Liability for Damage Caused by Space Objects, and the Convention (1975) on Registration of Objects Launched into Outer Space. The main European space centre is the Guiana Space Centre (CSG), settled in France. A clarification of the French legal framework was compulsory to allow the arrival of new launchers (Soyuz and Vega). This act defines the competent authority, the procedure of authorization and licenses, the regime for operations led from foreign countries, the control of spatial objects, the enabling of inspectors, the delegation of monitoring to CNES, the procedure for urgent measures necessary for the safety, the registration of spatial objects. In this framework, the operator is fully responsible of the operation that he leads. He is subjected to a regime of authorization and to governmental technical monitoring delegated to CNES. In case of litigation, the operator gets the State guarantee above a certain level of damage to third party. The introduction of FSOA has led to issue a Technical Regulation set forth, in particular for the safety of persons and property, the protection of public health and the environment. This general regulation is completed by a specific regulation applicable to CSG that covers the preparation phase of the launch, and all specificities of the launch range, as regards the beginning of the launch. The Technical Regulation is based on 30 years of Ariane's activities and on the

  18. Republic of Kazakhstan: Capacity Building through the Increasing of Space Activities

    NASA Astrophysics Data System (ADS)

    Omarova, G.

    Currently, a new space policy of the Republic of Kazakhstan is being formulated. Basic directions are: Adherence to principal agreements of the International Space Law. Optimal utilization and modernization of the Baikonur spaceport launch infrastructure. Creation of the national satellite communication system In accordance with the above listed goals and objectives, the following priority actions should be taken in national level: Increasing of the National activities in COPUOS Developing of the National space activities Program and Space activities Act; Funding of a new and upgraded facilities at the Baikonur spaceport; Creating of the educational and training system for national space industry In 2004 Kazakhstan-Russia cooperation in space activities has entered to a new perspectives. Both countries proceeded to develop joint projects in the field of space activities connected to modernization of existing space infrastructure of the Baikonur spaceport for launchers that meet requirements of ecological security. Three relevant bilateral agreements were signed. All signed documents ensure more wide participation of the Republic of Kazakhstan in realization of space programs and projects implemented at the Baikonur spaceport through shared financing and realization jointly with Russia of projects on building of the space missile complex ``Baiterek'' and launching of geostationary communication satellite. It opens great opportunities for Kazakhstan in terms of capacity building. Implementation of the mentioned two projects will allow to use the available scientific, technical and intellectual potential of the Republic of Kazakhstan in the field of space activities, and to utilize effectively the infrastructure of Baikonur complex, to get affordable access to space technologies, to create conditions for development, test and operation of space facilities, new science --capacity technologies that will lead to close integration with Russian space industry and with

  19. Collaboration with aviation — The key to commercialisation of space activities

    NASA Astrophysics Data System (ADS)

    Collins, Patrick; Funatsu, Yoshiyuki

    2000-07-01

    The US government's Commercial Space Act of 1998 and commitment to commercialise the International Space Station's operations have changed the direction of space development in the post-cold-war world definitively. During 1998 also the feasibility and great economic potential of space travel by the general public was acknowledged in publications by NASA, AIAA and the Japanese Keidanren. However, crewed space activities are all taxpayer-funded, primarily for scientific research; they have involved only a few hundred people traveling to space to date; and those involved have no experience of commercial passenger service operations. By contrast, aviation is a global industry, largely commercial, involving the range of activities from engineering design to marketing, and serving more than 1 billion passengers/year. Aviation has very high safety levels developed over decades of experience of carrying billions of passengers. Furthermore, the aviation industry also has extensive experience of operating rocket-powered piloted vehicles: during the 1950s several countries operated such vehicles sufficiently frequently to develop routine operations, maintenance and repair procedures. Consequently, in order to develop safe and profitable passenger travel services to, from and in space, people, companies and organisations with experience of space activities have a great deal to gain from collaboration with all parts of the aviation industry. Due to the potential economic value of this development, and the high cost to taxpayers of space activities today, governments should take steps to start this collaboration as soon as possible.

  20. SHS Processes in microgravity activities: first experiments in space

    NASA Astrophysics Data System (ADS)

    Merzhanov, Alexander G.

    Some data for study of self-propagating high-temperature synthesis (SHS) under microgravity are analyzed. This research direction seems to be promising because SHS is normally accompanied by such gravity-sensitive events as: melting of reagents and products, spreading of melt, coalescence of droplets, diffusion and convection in molten metals and nonmetals, buoyancy of solid particles and bubbles in the melt, nucleation of solid products, crystal growth, and sample deformation. The experiments carried out on the ground, under conditions of elevated artificial gravity, during parabolic flights, and aboard the Mir Space Station demonstrated a marked effect of gravity both on the process and products.

  1. Space Weather Activities of IONOLAB Group: TEC Mapping

    NASA Astrophysics Data System (ADS)

    Arikan, F.; Yilmaz, A.; Arikan, O.; Sayin, I.; Gurun, M.; Akdogan, K. E.; Yildirim, S. A.

    2009-04-01

    Being a key player in Space Weather, ionospheric variability affects the performance of both communication and navigation systems. To improve the performance of these systems, ionosphere has to be monitored. Total Electron Content (TEC), line integral of the electron density along a ray path, is an important parameter to investigate the ionospheric variability. A cost-effective way of obtaining TEC is by using dual-frequency GPS receivers. Since these measurements are sparse in space, accurate and robust interpolation techniques are needed to interpolate (or map) the TEC distribution for a given region in space. However, the TEC data derived from GPS measurements contain measurement noise, model and computational errors. Thus, it is necessary to analyze the interpolation performance of the techniques on synthetic data sets that can represent various ionospheric states. By this way, interpolation performance of the techniques can be compared over many parameters that can be controlled to represent the desired ionospheric states. In this study, Multiquadrics, Inverse Distance Weighting (IDW), Cubic Splines, Ordinary and Universal Kriging, Random Field Priors (RFP), Multi-Layer Perceptron Neural Network (MLP-NN), and Radial Basis Function Neural Network (RBF-NN) are employed as the spatial interpolation algorithms. These mapping techniques are initially tried on synthetic TEC surfaces for parameter and coefficient optimization and determination of error bounds. Interpolation performance of these methods are compared on synthetic TEC surfaces over the parameters of sampling pattern, number of samples, the variability of the surface and the trend type in the TEC surfaces. By examining the performance of the interpolation methods, it is observed that both Kriging, RFP and NN have important advantages and possible disadvantages depending on the given constraints. It is also observed that the determining parameter in the error performance is the trend in the Ionosphere

  2. Active space heating and hot water supply with solar energy

    SciTech Connect

    Karaki, S.; Loef, G. O.G.

    1981-04-01

    Technical and economic assessments are given of solar water heaters, both circulating, and of air-based and liquid-based solar space heating systems. Both new and retrofit systems are considered. The technical status of flat-plate and evacuated tube collectors and of thermal storage is also covered. Non-technical factors are also briefly discussed, including the participants in the use of solar heat, incentives and deterrents. Policy implications are considered as regards acceleration of solar use, goals for solar use, means for achieving goals, and interaction of governments, suppliers, and users. Government actions are recommended. (LEW)

  3. Virtual Reality: Developing a VR space for Academic activities

    NASA Astrophysics Data System (ADS)

    Kaimaris, D.; Stylianidis, E.; Karanikolas, N.

    2014-05-01

    Virtual reality (VR) is extensively used in various applications; in industry, in academia, in business, and is becoming more and more affordable for end users from the financial point of view. At the same time, in academia and higher education more and more applications are developed, like in medicine, engineering, etc. and students are inquiring to be well-prepared for their professional life after their educational life cycle. Moreover, VR is providing the benefits having the possibility to improve skills but also to understand space as well. This paper presents the methodology used during a course, namely "Geoinformatics applications" at the School of Spatial Planning and Development (Eng.), Aristotle University of Thessaloniki, to create a virtual School space. The course design focuses on the methods and techniques to be used in order to develop the virtual environment. In addition the project aspires to become more and more effective for the students and provide a real virtual environment with useful information not only for the students but also for any citizen interested in the academic life at the School.

  4. Active space debris removal using capture and ejection

    NASA Astrophysics Data System (ADS)

    Missel, Jonathan William

    2013-03-01

    Low Earth Orbit is over-cluttered with rogue objects that threaten existing technological assets and interfere with allocating new ones. Traditional satellite missions are not efficient enough to collect an appreciable amount of debris due to the high cost of orbit transfers. Many alternate proposals are politically controversial, costly, or dependent on undeveloped technology. This dissertation attempts to solve the problem by introducing a new mission architecture, Space Sweeper, and bespoke hardware, Sling-Sat, that sequentially captures and ejects debris plastically. Resulting momentum exchanges are exploited to aid in subsequent orbit transfers, thus saving fuel. Sling-Sat is a spinning satellite that captures debris at the ends of adjustable-length arms. Arm length controls the angular rate to achieve a desired tangential ejection speed. Timing the release exacts the ejection angle. This process redirects debris to burn up in the atmosphere, or reduce its lifetime, by lowering its perigee. This dissertation establishes feasibility of principles fundamental to the proposed concept. Hardware is conceptualized to accommodate Space Sweeper's specialized needs. Mathematical models are built for the purpose of analysis and simulation. A kinematic analysis investigates system demands and long-term behavior resulting from repeated debris interaction. A successful approach to enforce debris capture is established through optimal control techniques. A study of orbital parameters and their response to debris interactions builds an intuition for missions of this nature. Finally, a J2-compliant technique for path optimization is demonstrated. The results strongly support feasibility of the proposed mission.

  5. Radiological health risks to astronauts from space activities and medical procedures

    NASA Technical Reports Server (NTRS)

    Peterson, Leif E.; Nachtwey, D. Stuart

    1990-01-01

    Radiation protection standards for space activities differ substantially from those applied to terrestrial working situations. The levels of radiation and subsequent hazards to which space workers are exposed are quite unlike anything found on Earth. The new more highly refined system of risk management involves assessing the risk to each space worker from all sources of radiation (occupational and non-occupational) at the organ level. The risk coefficients were applied to previous space and medical exposures (diagnostic x ray and nuclear medicine procedures) in order to estimate the radiation-induced lifetime cancer incidence and mortality risk. At present, the risk from medical procedures when compared to space activities is 14 times higher for cancer incidence and 13 times higher for cancer mortality; however, this will change as the per capita dose during Space Station Freedom and interplanetary missions increases and more is known about the risks from exposure to high-LET radiation.

  6. Radiological health risks to astronauts from space activities and medical procedures

    SciTech Connect

    Paterson, L.E.; Nachtwey, D.S.

    1990-08-01

    Radiation protection standards for space activities differ substantially from those applied to terrestrial working situations. The levels of radiation and subsequent hazards to which space workers are exposed are quite unlike anything found on Earth. The new more highly refined system of risk management involves assessing the risk to each space worker from all sources of radiation (occupational and non-occupational) at the organ level. The risk coefficients were applied to previous space and medical exposures (diagnostic x ray and nuclear medicine procedures) in order to estimate the radiation-induced lifetime cancer incidence and mortality risk. At present, the risk from medical procedures when compared to space activities is 14 times higher for cancer incidence and 13 times higher for cancer mortality; however, this will change as the per capita dose during Space Station Freedom and interplanetary missions increases and more is known about the risks from exposure to high-LET radiation.

  7. Aeronautics and Space Report of the President: Fiscal Year 2000 Activities

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 1999, through September 30, 2000.

  8. Mobile phone usage in complex urban systems: a space-time, aggregated human activity study

    NASA Astrophysics Data System (ADS)

    Tranos, Emmanouil; Nijkamp, Peter

    2015-04-01

    The present study aims to demonstrate the importance of digital data for investigating space-time dynamics of aggregated human activity in urban systems. Such dynamics can be monitored and modelled using data from mobile phone operators regarding mobile telephone usage. Using such an extensive dataset from the city of Amsterdam, this paper introduces space-time explanatory models of aggregated human activity patterns. Various modelling experiments and results are presented, which demonstrate that mobile telephone data are a good proxy of the space-time dynamics of aggregated human activity in the city.

  9. Aeronautics and Space Report of the President - Fiscal Year 2010 Activities

    NASA Technical Reports Server (NTRS)

    2011-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2009, through September 30, 2010.

  10. Aeronautics and Space Report of the President: Fiscal Year 2007 Activities

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2006, through September 30, 2007.

  11. Aeronautics and Space Report of the President: Fiscal Year 2003 Activities

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year. In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2002, through September 30, 2003.

  12. Aeronautics and Space Report of the President: Fiscal Year 1999 Activities

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 1998, through September 30, 1999.

  13. Aeronautics and Space Report of the President - Fiscal Year 2008 Activities

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2007, through September 30, 2008.

  14. Aeronautics and Space Report of the President: Fiscal Year 2001 Activities

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a 'comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year.' In recent years the reports have been prepared on a fiscal-year basis consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2000, through September 30, 2001.

  15. Aeronautics and Space Report of the President: Fiscal Year 2005 Activities

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1 , 2004, through September 30, 2005.

  16. Skipping of Exons by Premature Termination of Transcription and Alternative Splicing within Intron-5 of the Sheep SCF Gene: A Novel Splice Variant

    PubMed Central

    Saravanaperumal, Siva Arumugam; Pediconi, Dario; Renieri, Carlo; La Terza, Antonietta

    2012-01-01

    Stem cell factor (SCF) is a growth factor, essential for haemopoiesis, mast cell development and melanogenesis. In the hematopoietic microenvironment (HM), SCF is produced either as a membrane-bound (−) or soluble (+) forms. Skin expression of SCF stimulates melanocyte migration, proliferation, differentiation, and survival. We report for the first time, a novel mRNA splice variant of SCF from the skin of white merino sheep via cloning and sequencing. Reverse transcriptase (RT)-PCR and molecular prediction revealed two different cDNA products of SCF. Full-length cDNA libraries were enriched by the method of rapid amplification of cDNA ends (RACE-PCR). Nucleotide sequencing and molecular prediction revealed that the primary 1519 base pair (bp) cDNA encodes a precursor protein of 274 amino acids (aa), commonly known as ‘soluble’ isoform. In contrast, the shorter (835 and/or 725 bp) cDNA was found to be a ‘novel’ mRNA splice variant. It contains an open reading frame (ORF) corresponding to a truncated protein of 181 aa (vs 245 aa) with an unique C-terminus lacking the primary proteolytic segment (28 aa) right after the D175G site which is necessary to produce ‘soluble’ form of SCF. This alternative splice (AS) variant was explained by the complete nucleotide sequencing of splice junction covering exon 5-intron (5)-exon 6 (948 bp) with a premature termination codon (PTC) whereby exons 6 to 9/10 are skipped (Cassette Exon, CE 6–9/10). We also demonstrated that the Northern blot analysis at transcript level is mediated via an intron-5 splicing event. Our data refine the structure of SCF gene; clarify the presence (+) and/or absence (−) of primary proteolytic-cleavage site specific SCF splice variants. This work provides a basis for understanding the functional role and regulation of SCF in hair follicle melanogenesis in sheep beyond what was known in mice, humans and other mammals. PMID:22719917

  17. NASDA activities in space solar power system research, development and applications

    NASA Technical Reports Server (NTRS)

    Matsuda, Sumio; Yamamoto, Yasunari; Uesugi, Masato

    1993-01-01

    NASDA activities in solar cell research, development, and applications are described. First, current technologies for space solar cells such as Si, GaAs, and InP are reviewed. Second, future space solar cell technologies intended to be used on satellites of 21st century are discussed. Next, the flight data of solar cell monitor on ETS-V is shown. Finally, establishing the universal space solar cell calibration system is proposed.

  18. Wireless Video System for Extra Vehicular Activity in the International Space Station and Space Shuttle Orbiter Environment

    NASA Technical Reports Server (NTRS)

    Loh, Yin C.; Boster, John; Hwu, Shian; Watson, John C.; deSilva, Kanishka; Piatek, Irene (Technical Monitor)

    1999-01-01

    The Wireless Video System (WVS) provides real-time video coverage of astronaut extra vehicular activities during International Space Station (ISS) assembly. The ISS wireless environment is unique due to the nature of the ISS structure and multiple RF interference sources. This paper describes how the system was developed to combat multipath, blockage, and interference using an automatic antenna switching system. Critical to system performance is the selection of receiver antenna installation locations determined using Uniform Geometrical Theory of Diffraction (GTD) techniques.

  19. Active Solution Space and Search on Job-shop Scheduling Problem

    NASA Astrophysics Data System (ADS)

    Watanabe, Masato; Ida, Kenichi; Gen, Mitsuo

    In this paper we propose a new searching method of Genetic Algorithm for Job-shop scheduling problem (JSP). The coding method that represent job number in order to decide a priority to arrange a job to Gannt Chart (called the ordinal representation with a priority) in JSP, an active schedule is created by using left shift. We define an active solution at first. It is solution which can create an active schedule without using left shift, and set of its defined an active solution space. Next, we propose an algorithm named Genetic Algorithm with active solution space search (GA-asol) which can create an active solution while solution is evaluated, in order to search the active solution space effectively. We applied it for some benchmark problems to compare with other method. The experimental results show good performance.

  20. Morphology Controllable Synthesis of ScF3:Er3+, Yb3+ Nano/Sub-Microncrystals by Hydrothermal/Solvothermal Process.

    PubMed

    Han, Lili; Li, Hua; Ci, Zhipeng; Wang, Yuhua

    2016-04-01

    In this paper, red phosphors Yb3+-Er3+ co-doped ScF3 nano/microcrystals were successfully prepared by a facile hydrothermal/solvothermal route using the sodium dodecyl benzene sulfonate (SDBS) as the surfactant. The structure, morphologies and up-conversion (UC) photoluminescence properties of the as-prepared products were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra, respectively. The SEM images show that the obtained samples are the uniform cubic and cuboid crystals. With the increase of the surfactant SDBS or the change in the solvent types, the sample change their size from nanometer to submicron. Upon the 980 nm laser diode excitation, the ScF3:Era+, Yb3+ nanocrystals exhibit red emission which can be assigned to the characteristic 4F9/2/4I15/2 transition of Er3+. In order to understand the emission mechanisms of ScF3:ErS+, Yb3+ nanocrystals, the dependence of UC luminescence intensity on the 980 nm excitation power was measured, suggesting that the UC phenomenon results from a two-photon process. Meanwhile, the emission intensities of the YbS+-Er3+ codoped ScF3 nano/sub-micro crystals with different solution composition show an obvious change under the 980 nm laser excitation. Therefore, the phosphors Yb3+-Er3+ co-doped ScF3 possibly have a potential application in the biological applications. PMID:27451694

  1. Advanced Embedded Active Assemblies for Extreme Space Applications

    NASA Technical Reports Server (NTRS)

    DelCastillo, Linda; Moussessian, Alina; Mojarradi, Mohammad; Kolawa, Elizabeth

    2009-01-01

    This work describes the development and evaluation of advanced technologies for the integration of electronic die within membrane polymers. Specifically, investigators thinned silicon die, electrically connecting them with circuits on flexible liquid crystal polymer (LCP), using gold thermo-compression flip chip bonding, and embedding them within the material. Daisy chain LCP assemblies were thermal cycled from -135 to +85degC (Mars surface conditions for motor control electronics). The LCP assembly method was further utilized to embed an operational amplifier designed for operation within the Mars surface ambient. The embedded op-amp assembly was evaluated with respect to the influence of temperature on the operational characteristics of the device. Applications for this technology range from multifunctional, large area, flexible membrane structures to small-scale, flexible circuits that can be fit into tight spaces for flex to fit applications.

  2. NASA. Marshall Space Flight Center Hydrostatic Bearing Activities

    NASA Technical Reports Server (NTRS)

    Benjamin, Theodore G.

    1991-01-01

    The basic approach for analyzing hydrostatic bearing flows at the Marshall Space Flight Center (MSFC) is briefly discussed. The Hydrostatic Bearing Team has responsibility for assessing and evaluating flow codes; evaluating friction, ignition, and galling effects; evaluating wear; and performing tests. The Office of Aerospace and Exploration Technology Turbomachinery Seals Tasks consist of tests and analysis. The MSFC in-house analyses utilize one-dimensional bulk-flow codes. Computational fluid dynamics (CFD) analysis is used to enhance understanding of bearing flow physics or to perform parametric analysis that are outside the bulk flow database. As long as the bulk flow codes are accurate enough for most needs, they will be utilized accordingly and will be supported by CFD analysis on an as-needed basis.

  3. On-orbit Metrology and Calibration Requirements for Space Station Activities Definition Study

    NASA Technical Reports Server (NTRS)

    Cotty, G. M.; Ranganathan, B. N.; Sorrell, A. L.

    1989-01-01

    The Space Station is the focal point for the commercial development of space. The long term routine operation of the Space Station and the conduct of future commercial activities suggests the need for in-space metrology capabilities analogous when possible to those on-Earth. The ability to perform periodic calibrations and measurements with proper traceability is imperative for the routine operation of the Space Station. An initial review, however, indicated a paucity of data related to metrology and calibration requirements for in-space operations. This condition probably exists because of the highly developmental aspect of space activities to date, their short duration, and nonroutine nature. The on-orbit metrology and calibration needs of the Space Station were examined and assessed. In order to achieve this goal, the following tasks were performed: an up-to-date literature review; identification of on-orbit calibration techniques; identification of sensor calibration requirements; identification of calibration equipment requirements; definition of traceability requirements; preparation of technology development plans; and preparation of the final report. Significant information and major highlights pertaining to each task is presented. In addition, some general (generic) conclusions/observations and recommendations that are pertinent to the overall in-space metrology and calibration activities are presented.

  4. Review and comparison of active space debris capturing and removal methods

    NASA Astrophysics Data System (ADS)

    Shan, Minghe; Guo, Jian; Gill, Eberhard

    2016-01-01

    Space debris is considered as a serious problem for operational space missions. Many enabling space debris capturing and removal methods have been proposed in the past decade and several methods have been tested on ground and/or in parabolic flight experiments. However, not a single space debris has been removed yet. A space debris object is usually non-cooperative and thus different with targets of on-orbit servicing missions. Thus, capturing and removal of space debris is significantly more challenging. One of the greatest challenges is how to reliably capture and remove a non-cooperative target avoiding to generate even more space debris. To motivate this research area and facilitate the development of active space debris removal, this paper provides review and comparison of the existing technologies on active space debris capturing and removal. It also reviews research areas worth investigating under each capturing and removal method. Frameworks of methods for capturing and removing space debris are developed. The advantages and drawbacks of the most relevant capturing and removal methods are addressed as well. In addition, examples and existing projects related to these methods are discussed.

  5. The self-consistent calculation of pseudo-molecule energy levels, construction of energy level correlation diagrams and an automated computation system for SCF-X(Alpha)-SW calculations

    NASA Technical Reports Server (NTRS)

    Schlosser, H.

    1981-01-01

    The self consistent calculation of the electronic energy levels of noble gas pseudomolecules formed when a metal surface is bombarded by noble gas ions is discussed along with the construction of energy level correlation diagrams as a function of interatomic spacing. The self consistent field x alpha scattered wave (SCF-Xalpha-SW) method is utilized. Preliminary results on the Ne-Mg system are given. An interactive x alpha programming system, implemented on the LeRC IBM 370 computer, is described in detail. This automated system makes use of special PROCDEFS (procedure definitions) to minimize the data to be entered manually at a remote terminal. Listings of the special PROCDEFS and of typical input data are given.

  6. INCORPORATING ROUTINE ACTIVITIES, ACTIVITY SPACES, AND SITUATIONAL DEFINITIONS INTO THE SOCIAL SCHEMATIC THEORY OF CRIME*

    PubMed Central

    BARR, ASHLEY B.; LEI, MAN-KIT; STEWART, ERIC

    2014-01-01

    Simons and Burt’s (2011) social schematic theory (SST) of crime posits that adverse social factors are associated with offending because they promote a set of social schemas (i.e., a criminogenic knowledge structure) that elevates the probability of situational definitions favorable to crime. This study extends the SST model by incorporating the role of contexts for action. Furthermore, the study advances tests of the SST by incorporating a measure of criminogenic situational definitions to assess whether such definitions mediate the effects of schemas and contexts on crime. Structural equation models using 10 years of panel data from 582 African American youth provided strong support for the expanded theory. The results suggest that childhood and adolescent social adversity fosters a criminogenic knowledge structure as well as selection into criminogenic activity spaces and risky activities, all of which increase the likelihood of offending largely through situational definitions. Additionally, evidence shows that the criminogenic knowledge structure interacts with settings to amplify the likelihood of situational definitions favorable to crime. PMID:26392633

  7. Using the PAIR-up Model to Evaluate Active Learning Spaces

    ERIC Educational Resources Information Center

    Whiteside, Aimee L.; Jorn, Linda; Duin, Ann Hill; Fitzgerald, Steve

    2009-01-01

    This article presents a study on using the PAIR-up model to evaluate active learning spaces. The PAIR-up model takes advantage of interdisciplinary partnerships, assessment, innovation, and reevaluation of current views to support learning space design. Using PAIR-up, the University of Minnesota designed, constructed, and assessed two pilot Active…

  8. 48 CFR 1852.228-76 - Cross-waiver of liability for international space station activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of liability provision authorized by 14 CFR 1266.102. (2) “Damage” means: (i) Bodily injury to, or... for international space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS...

  9. 48 CFR 1852.228-76 - Cross-waiver of liability for international space station activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of liability provision authorized by 14 CFR 1266.102. (2) “Damage” means: (i) Bodily injury to, or... for international space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS...

  10. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  11. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  12. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  13. Individualized Instruction in Science, Time-Space-Matter, Learning Activity Packages.

    ERIC Educational Resources Information Center

    Kuczma, R. M.

    Learning Activity Packages (LAP) relating to time, space, and matter are presented for use in sampling a new type of learning for a whole year. Besides the unit on introduction to individualized learning, 11 major topics are incorporated into three other units: (1) observation of the physical world, (2) space and exploration for environmental…

  14. Young Scientists Explore Inner & Outer Space. Book 6--Intermediate Level. A Good Apple Activity Book.

    ERIC Educational Resources Information Center

    DeBruin, Jerry

    Designed to develop creativity in young learners, this book contains interdisciplinary activities which focus on the theme of space (inner and outer). Activity pages are provided that can serve as front and back covers of a student booklet and the suggested activities can be duplicated for insertion between the covers resulting in a booklet for…

  15. Young adolescents' perceived activity space risk, peer networks, and substance use.

    PubMed

    Mason, Michael; Mennis, Jeremy; Way, Thomas; Light, John; Rusby, Julie; Westling, Erika; Crewe, Stephanie; Flay, Brian; Campbell, Leah; Zaharakis, Nikola; McHenry, Chantal

    2015-07-01

    Adolescent substance use is a developmentally contingent social practice that is constituted within the routine social-environment of adolescents' lives. Few studies have examined peer networks, perceived activity space risk (risk of substance use at routine locations), and substance use. We examined the moderating influence of peer network characteristics on the relationship between perceived activity space risk and substance use among a sample of 250 urban adolescents. Significant interactions were found between peer networks and perceived activity space risk on tobacco and marijuana use, such that protective peer networks reduced the effect of activity place risk on substance use. A significant 3-way interaction was found on marijuana use indicating that gender moderated peer network's effect on activity space risk. Conditional effect analysis found that boys' peer networks moderated the effect of perceived activity space risk on marijuana use, whereas for girls, the effect of perceived activity space risk on marijuana use was not moderated by their peer networks. These findings could advance theoretical models to inform social-environmental research among adolescents. PMID:26026598

  16. Report to the Congress from The President of the United States. United States Aeronautics and Space Activities 1967.

    ERIC Educational Resources Information Center

    Johnson, Lyndon B.

    This report extensively reviews the progress of the United States in space during 1967, the tenth year of the space age. The first chapter of the report summarizes the 1967 space activities; and each of the remaining 13 chapters is devoted to reviewing the space-related activities of a particular federal agency (13 agencies included). Appendices…

  17. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  18. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  19. Emergent Public Spaces: Generative Activities on Function Interpolation

    ERIC Educational Resources Information Center

    Carmona, Guadalupe; Dominguez, Angeles; Krause, Gladys; Duran, Pablo

    2011-01-01

    This study highlights ways in which generative activities may be coupled with network-based technologies in the context of teacher preparation to enhance preservice teachers' cognizance of how their own experience as students provides a blueprint for the learning environments they may need to generate in their future classrooms. In this study, the…

  20. Thin Film on CMOS Active Pixel Sensor for Space Applications

    PubMed Central

    Schulze Spuentrup, Jan Dirk; Burghartz, Joachim N.; Graf, Heinz-Gerd; Harendt, Christine; Hutter, Franz; Nicke, Markus; Schmidt, Uwe; Schubert, Markus; Sterzel, Juergen

    2008-01-01

    A 664 × 664 element Active Pixel image Sensor (APS) with integrated analog signal processing, full frame synchronous shutter and random access for applications in star sensors is presented and discussed. A thick vertical diode array in Thin Film on CMOS (TFC) technology is explored to achieve radiation hardness and maximum fill factor.

  1. Second-Order Perturbation Theory for Generalized Active Space Self-Consistent-Field Wave Functions.

    PubMed

    Ma, Dongxia; Li Manni, Giovanni; Olsen, Jeppe; Gagliardi, Laura

    2016-07-12

    A multireference second-order perturbation theory approach based on the generalized active space self-consistent-field (GASSCF) wave function is presented. Compared with the complete active space (CAS) and restricted active space (RAS) wave functions, GAS wave functions are more flexible and can employ larger active spaces and/or different truncations of the configuration interaction expansion. With GASSCF, one can explore chemical systems that are not affordable with either CASSCF or RASSCF. Perturbation theory to second order on top of GAS wave functions (GASPT2) has been implemented to recover the remaining electron correlation. The method has been benchmarked by computing the chromium dimer ground-state potential energy curve. These calculations show that GASPT2 gives results similar to CASPT2 even with a configuration interaction expansion much smaller than the corresponding CAS expansion. PMID:27276688

  2. The Living Ocean. SeaWiFS: Studying Ocean Color from Space. Teacher's Guide with Activities

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This educational document, designed for grades 9 to 10, discusses the observation of oceans from space. Topics covered include ocean color, the role of phytoplankton, the carbon cycle, and the greenhouse effect. Activities and discussion questions are presented.

  3. Life extension activities for the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Walyus, Keith D.; Pepe, Joyce; Prior, Michael

    2004-10-01

    Without an additional Hubble Space Telescope (HST) Servicing Mission (SM4), the HST Project will face numerous challenges to keep the telescope operating for as long as possible. As part of SM4, the HST Project planned to install various upgrades to the telescope including the installation of new batteries and new rate integrating gyros. Without these upgrades, reliability analyses and trend projections indicate that the spacecraft will lose the capability to conduct science operations later this decade. The HST team is being challenged to maximize the telescope's remaining operational lifetime, and also maximize its science output and quality. The two biggest areas of concern are the age and condition of the batteries and gyros. Together they comprise the largest risk to telescope productivity and safety and present the biggest challenges to the HST team. The six nickel-hydrogen (NiH2) batteries on HST are the original batteries from launch. With fourteen years of operational life, these batteries have -lasted longer than those on any comparable mission. Yet as with all batteries, their capacity has been declining. Engineers are examining various methods to prolong the life of these mission critical batteries, and retard the rate of degradation. In addition to the batteries, the National Aeronautics and Space Administration (NASA) scheduled all six gyros to be replaced on SM4. Two of the six gyros have already failed, leaving four available for operational use. To be able to conduct science operations, the telescope currently needs three gyros. Efforts are underway to enable a guiding mode that will require only two gyros. In this mode, however, science target scheduling will be strongly driven by new factors (such as star tracker availability), which may ultimately reduce science gathering efficiency. The status on this effort and its potential impact on science operations will be discussed. This paper will focus on these and other efforts to prolong the life of

  4. Sky Luminaries in the Space Orienting Activity of Homo Sapiens in the Middle Palaeolithic

    NASA Astrophysics Data System (ADS)

    Kaurov, E. N.

    Data describing the beginnings of the space orienting activity of Homo sapiens is analysed and systematized: observation of the Pole and the recognition of Ursa Major were used as the basis of the determination of the points of the compass. Data and results from astronomy, history of astronomy, archaeology and palaeoanthropology were used for the reconstruction of the evolution of the space orienting activity of Homo sapiens.

  5. Thermal Technology Development Activities at the Goddard Space Flight Center - 2001

    NASA Technical Reports Server (NTRS)

    Butler, Dan

    2002-01-01

    This presentation provides an overview of thermal technology development activities carried out at NASA's Goddard Space Flight Center during 2001. Specific topics covered include: two-phase systems (heat pipes, capillary pumped loops, vapor compression systems and phase change materials), variable emittance systems, advanced coatings, high conductivity materials and electrohydrodynamic (EHD) thermal coatings. The application of these activities to specific space missions is also discussed.

  6. Assessment of MSFCs Process for the Development and Activation of Space Act Agreement

    NASA Technical Reports Server (NTRS)

    Daugherty, Rachel

    2014-01-01

    Space Act Agreements (SAAs) are contractual agreements that NASA utilizes to form partnerships with researchers, industry, and academia to stimulate cutting-edge innovation within the science and technology communities. center dot This study assessed the current SAA development and activation process at Marshall Space Flight Center (MSFC) to determine if improvements could be implemented to increase productivity, decrease time to activation, and improve the quality of deliverables.

  7. Life Extension Activities for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Walyus, Keith D.; Pepe, Joyce A. K.; Prior, Michael

    2004-01-01

    With the cancellation of the Hubble Space Telescope (HST) Servicing Mission 4 (SM4), the HST Project will face numerous challenges to keep the Telescope operating during the remainder of the decade. As part of the SM4, the HST Project had planned to install various upgrades to the Telescope including the installation of new batteries and new rate integrating gyros. Without these upgrades, reliability analysis indicates that the spacecraft will lose the capability to conduct science operations later this decade. The HST team will be severely challenged to maximize the Telescope's remaining operational lifetime, while still trying to maximize - its science output and quality. Two of the biggest areas of concern are the age and condition of the batteries and gyros. Together they offer the largest potential extension in Telescope lifetime and present the biggest challenges to the HST team. The six Ni-H batteries on HST are the original batteries from launch. With fourteen years of operational life, these batteries have collectively lasted longer than any other comparable mission. Yet as with all batteries, their capacity has been declining. Engineers are examining various methods to prolong the life of these mission critical batteries, and retard the rate of degradation. This paper will focus on these and other efforts to prolong the life of the HST, thus enabling it to remain a world-class observatory for as long as possible.

  8. Redefining neighborhoods using common destinations: social characteristics of activity spaces and home census tracts compared.

    PubMed

    Jones, Malia; Pebley, Anne R

    2014-06-01

    Research on neighborhood effects has focused largely on residential neighborhoods, but people are exposed to many other places in the course of their daily lives-at school, at work, when shopping, and so on. Thus, studies of residential neighborhoods consider only a subset of the social-spatial environment affecting individuals. In this article, we examine the characteristics of adults' "activity spaces"-spaces defined by locations that individuals visit regularly-in Los Angeles County, California. Using geographic information system (GIS) methods, we define activity spaces in two ways and estimate their socioeconomic characteristics. Our research has two goals. First, we determine whether residential neighborhoods represent the social conditions to which adults are exposed in the course of their regular activities. Second, we evaluate whether particular groups are exposed to a broader or narrower range of social contexts in the course of their daily activities. We find that activity spaces are substantially more heterogeneous in terms of key social characteristics, compared to residential neighborhoods. However, the characteristics of both home neighborhoods and activity spaces are closely associated with individual characteristics. Our results suggest that most people experience substantial segregation across the range of spaces in their daily lives, not just at home. PMID:24719273

  9. Declassified American Government Documents Show a Broad and In-Depth Interest in Soviet Space Activities

    NASA Astrophysics Data System (ADS)

    Pesavento, P.

    Back in 1993, when this author was able to acquire one of the first US National Intelligence Estimate (NIE) documents declassified on the Soviet Space Program [1], there was a dearth of materials concerning the USSR's space activities from a US intelligence perspective. Now, a decade on, the situation has dramatically changed. As a plethora of US government agencies labor to disgorge their materials from the era of the Cold War, space historians and observers now have access to many new documents, which shed both exciting and new light on Soviet space activities, and how the US viewed as well as interpreted them. Coupled with the fact that many of these are now available to be read via the Internet, and with most of the documents available only recently, a new era in space history research is now in hand. This article is intended to provide a broad overview of what is now available, and mention some highlights.

  10. On the design and feasibility of a pneumatically supported actively guided space tower

    NASA Astrophysics Data System (ADS)

    Seth, Raj Kumar

    2010-07-01

    Space tethers have been investigated widely as a means to provide easy access to space. However, the design and construction of such a device presents significant unsolved technological challenges. An alternative approach is proposed to the construction of a space elevator that utilises a free-standing core structure to provide access to near space regions and to reduce the cost of space launch. The theoretical and experimental investigation of the bending of inflatable cylindrical cantilevered beams made of modem fabric materials provides the basis for the design of an inflatable space tower. Experimental model structures were deployed and tested in order to determine design guidelines for the core structure. The feasibility of the construction of a thin walled inflatable space tower of 20 km vertical extent comprised of pneumatically inflated sections that are actively controlled and stabilised to balance external disturbances and support the structure is discussed. The response of the structure under wind loads is analyzed and taken into account for determining design guidelines. Such an approach avoids problems associated with a space tether including material strength constraints, the need for in-space construction, the fabrication of a cable at least 50,000 km in length, and the ageing and meteorite damage effects associated with a thin tether or cable in Low Earth Orbit. A suborbital tower of 20 km height would provide an ideal mounting point where a geostationary orbital space tether could be attached without experiencing atmospheric turbulence and weathering in the lower atmosphere. The tower can be utilized as a platform for various scientific and space missions or as an elevator to carry payloads and tourists. In addition, space towers can significantly be utilized to generate electrical power by harvesting high altitude renewable energy sources. Keywords: Space Elevator, Inflatable Space Tower, Inflatable Structure, Inflatable Beam, Inflatable Multiple

  11. CDPP activities: Promoting research and education in space physics

    NASA Astrophysics Data System (ADS)

    Genot, V. N.; Andre, N.; Cecconi, B.; Gangloff, M.; Bouchemit, M.; Dufourg, N.; Pitout, F.; Budnik, E.; Lavraud, B.; Rouillard, A. P.; Heulet, D.; Bellucci, A.; Durand, J.; Delmas, D.; Alexandrova, O.; Briand, C.; Biegun, A.

    2015-12-01

    The French Plasma Physics Data Centre (CDPP, http://cdpp.eu/) addresses for more than 15 years all issues pertaining to natural plasma data distribution and valorization. Initially established by CNES and CNRS on the ground of a solid data archive, CDPP activities diversified with the advent of broader networks and interoperability standards, and through fruitful collaborations (e.g. with NASA/PDS): providing access to remote data, designing and building science driven analysis tools then became at the forefront of CDPP developments. For instance today AMDA helps scientists all over the world accessing and analyzing data from ancient to very recent missions (from Voyager, Galileo, Geotail, ... to Maven, Rosetta, MMS, ...) as well as results from models and numerical simulations. Other tools like the Propagation Tool or 3DView allow users to put their data in context and interconnect with other databases (CDAWeb, MEDOC) and tools (Topcat). This presentation will briefly review this evolution, show technical and science use cases, and finally put CDPP activities in the perspective of ongoing collaborative projects (Europlanet H2020, HELCATS, ...) and future missions (Bepicolombo, Solar Orbiter, ...).

  12. Structural Dynamics Experimental Activities in Ultra-Lightweight and Inflatable Space Structures

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Lassiter, John O.; Ross, Brian P.

    2001-01-01

    This paper reports recently completed structural dynamics experimental activities with new ultralightweight and inflatable space structures (a.k.a., "Gossamer" spacecraft) at NASA Langley Research Center, NASA Marshall Space Flight Center, and NASA Goddard Space Flight Center. Nine aspects of this work are covered, as follows: 1) inflated, rigidized tubes, 2) active control experiments, 3) photogrammetry, 4) laser vibrometry, 5) modal tests of inflatable structures, 6) in-vacuum modal tests, 7) tensioned membranes, 8) deployment tests, and 9) flight experiment support. Structural dynamics will play a major role in the design and eventual in-space deployment and performance of Gossamer spacecraft, and experimental R&D work such as this is required now to validate new analytical prediction methods. The activities discussed in the paper are pathfinder accomplishments, conducted on unique components and prototypes of future spacecraft systems.

  13. Structural Dynamics Experimental Activities in Ultra-Lightweight and Inflatable Space Structures

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Lassiter, John O.; Ross, Brian P.

    2001-01-01

    This paper reports recently completed structural dynamics experimental activities with new ultra-lightweight and inflatable space structures (a.k.a., "Gossamer" spacecraft) at NASA Langley Research Center, NASA Marshall Space Flight Center, and NASA Goddard Space Flight Center. Nine aspects of this work are covered: 1) inflated, rigidized tubes, 2) active control experiments, 3) photogrammetry, 4) laser vibrometry, 5) modal tests of inflatable structures, 6) in-vacuum modal tests, 7) tensioned membranes, 8) deployment tests, and 9) flight experiment support. Structural dynamics will play a major role in the design and eventually in-space deployment and performance of Gossamer spacecraft. Experimental research and development such as this is required to validate new analysis methods. The activities discussed in the paper are pathfinder accomplishments. conducted on unique components and prototypes of future spacecraft systems.

  14. Enzyme activities and membrane lipids in artemia cysts after a long duration space flight

    NASA Astrophysics Data System (ADS)

    Gaubin, Y.; Prévost, M. C.; Cariven, C.; Pianezzi, B.; Planel, H.; Soleilhavoup, J. P.

    1996-01-01

    In the Free Flyer Biostack Experiment (L.D.E.F. mission) investigations have shown that biological objects in a resting state can survive more than 5.5 years of exposure to the space factors in particular microgravity and cosmic rays. We have measured enzyme activities involved in metabolic pathways of sugar and lipid degradation and determined phospholipid composition. Pyruvate kinase and glucose-6-phosphate dehydrogenase activities in space-exposed cysts were higher than in earth controls after 1 hour incubation. In controls, total phospholipids remained unchanged, on the contrary they increased significantly in space-exposed cysts. The rate of metabolism of various phospholipid components was unchanged in controls allowing the development while the level of most of them decreased in space-exposed cysts except for phosphatidylcholine. Enzyme activities (acetylhydrolase, phospholipase A_2 and lyso phospholipase) involved in phospholipid degradation increased ; however, activities were much higher in space-exposed cysts. In conclusion, the long duration space flight resulted in an increase of the metabolic activity correlated with a faster development within the first 20 hours of post flight incubation.

  15. Lunar bases and space activities of the 21st century

    SciTech Connect

    Mendell, W.W.

    1985-01-01

    The present conference gives attention to such major aspects of lunar colonization as lunar base concepts, lunar transportation, lunar science research activities, moon-based astronomical researches, lunar architectural construction, lunar materials and processes, lunar oxygen production, life support and health maintenance in lunar bases, societal aspects of lunar colonization, and the prospects for Mars colonization. Specific discussions are presented concerning the role of nuclear energy in lunar development, achromatic trajectories and the industrial scale transport of lunar resources, advanced geologic exploration from a lunar base, geophysical investigations of the moon, moon-based astronomical interferometry, the irradiation of the moon by particles, cement-based composites for lunar base construction, electrostatic concentration of lunar soil minerals, microwave processing of lunar materials, a parametric analysis of lunar oxygen production, hydrogen from lunar regolith fines, metabolic support for a lunar base, past and future Soviet lunar exploration, and the use of the moons of Mars as sources of water for lunar bases.

  16. Space-Based Detection of Sinkhole Activity in Central Florida

    NASA Astrophysics Data System (ADS)

    Oliver-Cabrera, T.; Kruse, S.; Wdowinski, S.

    2015-12-01

    Central Florida's thick carbonate deposits and hydrological conditions have made the area prone to sinkhole development. Sinkhole collapse is a major geologic hazard in central Florida threatening human life and causing substantial damage to property. According to the Florida Senate report in 2010, between 2006-2010 total insurance claims due to sinkhole activity were around $200 million per year. Detecting sinkhole deformation before a collapse is a very difficult task, due to small or sometimes unnoticeable surface changes. Most techniques used to monitor sinkholes provide very localized information and cannot be implemented to study broad areas. This is the case of central Florida, where the active zone spans over hundreds of square-kilometers. In this study we use Interferometric Synthetic Aperture Radar (InSAR) observations acquired over several locations in central Florida to detect possible pre-collapse deformation. The study areas were selected because they have shown suspicious sinkhole behavior. One of the sites collapsed on March 2013 destroying a property and killing a man. To generate the InSAR results we use six datasets acquired by the TerraSAR-X and Cosmo-SkyMed satellites with various acquisition modes reflecting pixel resolutions between 25cm and 2m. Preliminary InSAR results show good coherence over constructed areas and low coherence in vegetated zones, justifying our analysis that focuses on the man-made structures. After full datasets will be acquired, a Persistent Scatterer Interferometry (PSI) time series analysis will be performed for detecting localized deformation at spatial scale of 1-5 meters. The project results will be verified using Ground Penetrating Radar.

  17. Active space debris removal by a hybrid propulsion module

    NASA Astrophysics Data System (ADS)

    DeLuca, L. T.; Bernelli, F.; Maggi, F.; Tadini, P.; Pardini, C.; Anselmo, L.; Grassi, M.; Pavarin, D.; Francesconi, A.; Branz, F.; Chiesa, S.; Viola, N.; Bonnal, C.; Trushlyakov, V.; Belokonov, I.

    2013-10-01

    During the last 40 years, the mass of the artificial objects in orbit increased quite steadily at the rate of about 145 metric tons annually, leading to a total tally of approximately 7000 metric tons. Now, most of the cross-sectional area and mass (97% in LEO) is concentrated in about 4600 intact objects, i.e. abandoned spacecraft and rocket bodies, plus a further 1000 operational spacecraft. Simulations and parametric analyses have shown that the most efficient and effective way to prevent the outbreak of a long-term exponential growth of the catalogued debris population would be to remove enough cross-sectional area and mass from densely populated orbits. In practice, according to the most recent NASA results, the active yearly removal of approximately 0.1% of the abandoned intact objects would be sufficient to stabilize the catalogued debris in low Earth orbit, together with the worldwide adoption of mitigation measures. The candidate targets for removal would have typical masses between 500 and 1000 kg, in the case of spacecraft, and of more than 1000 kg, in the case of rocket upper stages. Current data suggest that optimal active debris removal missions should be carried out in a few critical altitude-inclination bands. This paper deals with the feasibility study of a mission in which the debris is removed by using a hybrid propulsion module as propulsion unit. Specifically, the engine is transferred from a servicing platform to the debris target by a robotic arm so to perform a controlled disposal. Hybrid rocket technology for de-orbiting applications is considered a valuable option due to high specific impulse, intrinsic safety, thrust throttle ability, low environmental impact and reduced operating costs. Typically, in hybrid rockets a gaseous or liquid oxidizer is injected into the combustion chamber along the axial direction to burn a solid fuel. However, the use of tangential injection on a solid grain Pancake Geometry allows for more compact design of

  18. A suite of methods for representing activity space in a healthcare accessibility study

    PubMed Central

    Sherman, Jill E; Spencer, John; Preisser, John S; Gesler, Wilbert M; Arcury, Thomas A

    2005-01-01

    Background "Activity space" has been used to examine how people's habitual movements interact with their environment, and can be used to examine accessibility to healthcare opportunities. Traditionally, the standard deviational ellipse (SDE), a Euclidean measure, has been used to represent activity space. We describe the construction and application of the SDE at one and two standard deviations, and three additional network-based measures of activity space using common tools in GIS: the road network buffer (RNB), the 30-minute standard travel time polygon (STT), and the relative travel time polygon (RTT). We compare the theoretical and methodological assumptions of each measure, and evaluate the measures by examining access to primary care services, using data from western North Carolina. Results Individual accessibility is defined as the availability of healthcare opportunities within that individual's activity space. Access is influenced by the shape and area of an individual's activity space, the spatial distribution of opportunities, and by the spatial structures that constrain and direct movement through space; the shape and area of the activity space is partly a product of how it is conceptualized and measured. Network-derived measures improve upon the SDE by incorporating the spatial structures (roads) that channel movement. The area of the STT is primarily influenced by the location of a respondent's residence within the road network hierarchy, with residents living near primary roads having the largest activity spaces. The RNB was most descriptive of actual opportunities and can be used to examine bypassing. The area of the RTT had the strongest correlation with a healthcare destination being located inside the activity space. Conclusion The availability of geospatial technologies and data create multiple options for representing and operationalizing the construct of activity space. Each approach has its strengths and limitations, and presents a different

  19. A small active dosimeter for applications in space

    NASA Astrophysics Data System (ADS)

    Ritter, Birgit; Maršálek, Karel; Berger, Thomas; Burmeister, Sönke; Reitz, Günther; Heber, Bernd

    2014-06-01

    The radiation field in low Earth orbits (LEO) differs significantly from the radiation environment on Earth's surface. Exposures are by far higher and pose an additional health risk for astronauts. Continuous monitoring is therefore a necessary task in the frame of radiation protection measures. A small battery-driven active dosimeter telescope based on silicon detectors meeting the requirements for LEO applications has been developed. The instrument, the Mobile Dosimetric Telescope (MDT), is designed to measure the absorbed dose rate and the linear energy transfer (LET) spectra. From the latter the mean quality factor of the radiation field can be derived and hence an estimate of the dose equivalent as a measure of the exposure. The calibration of the device is done using radioactive isotopes and heavy ions. Fragmentation products of heavy ions are used to show the ability of the MDT to reliably detect energy depositions from high energetic nuclei. Radiation measurements inside aircraft during long distance flights, serving as field tests of the instrument, prove the good performance of the instrument.

  20. Rocket-Based Combined Cycle Activities in the Advanced Space Transportation Program Office

    NASA Technical Reports Server (NTRS)

    Hueter, Uwe; Turner, James

    1999-01-01

    NASA's Office of Aero-Space Technology (OAST) has established three major goals, referred to as, "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala. focuses on future space transportation technologies Under the "Access to Space" pillar. The Core Technologies Project, part of ASTP, focuses on the reusable technologies beyond those being pursued by X-33. One of the main activities over the past two and a half years has been on advancing the rocket-based combined cycle (RBCC) technologies. In June of last year, activities for reusable launch vehicle (RLV) airframe and propulsion technologies were initiated. These activities focus primarily on those technologies that support the decision to determine the path this country will take for Space Shuttle and RLV. This year, additional technology efforts in the reusable technologies will be awarded. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion.

  1. Redefining Neighborhoods Using Common Destinations: Social Characteristics of Activity Spaces and Home Census Tracts Compared

    PubMed Central

    Jones, Malia; Pebley, Anne R.

    2014-01-01

    Research on neighborhood effects has focused largely on residential neighborhoods, but people are exposed to many other places in the course of their daily lives—at school, at work, when shopping, and so on. Thus, studies of residential neighborhoods consider only a subset of the social-spatial environment affecting individuals. In this article, we examine the characteristics of adults’ “activity spaces”—spaces defined by locations that individuals visit regularly, in Los Angeles County, California. Using geographic information system (GIS) methods, we define activity spaces in two ways and estimate their socioeconomic characteristics. Our research has two goals. First, we determine whether residential neighborhoods represent the social conditions to which adults are exposed in the course of their regular activities. Second, we evaluate whether particular groups are exposed to a broader or narrower range of social contexts in the course of their daily activities. We find that activity spaces are substantially more heterogeneous in terms of key social characteristics, compared to residential neighborhoods. However, the characteristics of both home neighborhoods and activity spaces are closely associated with individual characteristics. Our results suggest that most people experience substantial segregation across the range of spaces in their daily lives, not just at home. PMID:24719273

  2. Individualized Instruction in Science, Earth-Space Project, Self-Directed Activities.

    ERIC Educational Resources Information Center

    Kuczma, R. M.

    As a supplement to Learning Activity Packages (LAP) of the earth-space project, this manual presents self-directed activities especially designed for individualized instruction. Besides an introduction to LAP characteristics, sets of instructions are given in connection with the metric system, the earth's dimensions, indirect evidence for atomic…

  3. Individualized Instruction in Science, Time-Space-Matter, Self-Directed Activities.

    ERIC Educational Resources Information Center

    Kuczma, R. M.

    As a supplement to Learning Activity Packages (LAP) on the time-space-matter subject, details are presented for self-directed activities. Major descriptions are given on the background of LAP characteristics, metric system, profile graph construction, spectroscope operation, radiant energy measurement, sunspot effects, density determination,…

  4. Communication: Active space decomposition with multiple sites: Density matrix renormalization group algorithm

    SciTech Connect

    Parker, Shane M.; Shiozaki, Toru

    2014-12-07

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE{sub h} or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.

  5. Autonomous Sensorweb Operations for Integrated Space, In-Situ Monitoring of Volcanic Activity

    NASA Technical Reports Server (NTRS)

    Chien, Steve A.; Doubleday, Joshua; Kedar, Sharon; Davies, Ashley G.; Lahusen, Richard; Song, Wenzhan; Shirazi, Behrooz; Mandl, Daniel; Frye, Stuart

    2010-01-01

    We have deployed and demonstrated operations of an integrated space in-situ sensorweb for monitoring volcanic activity. This sensorweb includes a network of ground sensors deployed to the Mount Saint Helens volcano as well as the Earth Observing One spacecraft. The ground operations and space operations are interlinked in that ground-based intelligent event detections can cause the space segment to acquire additional data via observation requests and space-based data acquisitions (thermal imagery) can trigger reconfigurations of the ground network to allocate increased bandwidth to areas of the network best situated to observe the activity. The space-based operations are enabled by an automated mission planning and tasking capability which utilizes several Opengeospatial Consortium (OGC) Sensorweb Enablement (SWE) standards which enable acquiring data, alerts, and tasking using web services. The ground-based segment also supports similar protocols to enable seamless tasking and data delivery. The space-based segment also supports onboard development of data products (thermal summary images indicating areas of activity, quicklook context images, and thermal activity alerts). These onboard developed products have reduced data volume (compared to the complete images) which enables them to be transmitted to the ground more rapidly in engineering channels.

  6. National Report Sweden: Swedish Space Activities- An Overview with a Focus on Balloons and Rockets

    NASA Astrophysics Data System (ADS)

    Dannenberg, K.

    2015-09-01

    The paper gives a brief overview of Swedish space activities with a focus on balloon and rocket projects, launched or scheduled for launch in the near future from Esrange Space Center. Several on-going national balloon and rocket projects are described in brief. Sweden is also a major player in sounding rocket activities within the ESA Elips programme as provider of launch services and developer of modules for microgravity experiments. Another important activity, described below, is the student programme REXUS/BEXUS, carried out within the framework of bilateral agreement between DLR and SNSB, and in collaboration with ESA. It should also be noted that several other balloons and rockets have been launched from Esrange Space Center during the reporting period. The present paper focuses, however, on the projects led by Swedish Principal Investigators and activities with a major involvement of Swedish scientists and engineers.

  7. Harpoon technology development for the active removal of space debris

    NASA Astrophysics Data System (ADS)

    Dudziak, Roger; Tuttle, Sean; Barraclough, Simon

    2015-08-01

    This paper presents the results of preliminary empirical testing and numerical modelling carried out to demonstrate the effectiveness of using a harpoon in an ADR application. Empirical testing involving the impact of blunt and conical shaped steel tips into 3 mm Al plate showed that the ballistic limit varies in proportion to the tip circumference, with conical shapes resulting in a higher relative ballistic limit due to the additional energy required for petaling. The creation of secondary debris was also monitored. It was found that blunt shapes created a plug during penetration as a result of shearing around the periphery of the projectile, whilst conical tips resulted in minor spalling and fragmentation. Preliminary oblique impact testing with conical and blunt tips showed that the ballistic limit increases with obliquity at a greater rate for blunt tips than conical ones. Impact testing of 3 mm Al plate with conical projectiles at low temperatures showed a more brittle fracture mode when compared with targets impacted at room temperature. As such, the fragmentation and spalling evident in room temperature targets was absent. The energy required to perforate the cooled plates also increased. Impact testing of Al panel obstructed with fixed heat pipes showed that the harpoon could successfully penetrate a target panel with such an obstruction due to shearing of the pipe flange. Testing of two lock on mechanisms showed that both a spring activated and integrated toggle could reliably open upon impact. This testing also used a tensile testing machine to show that both designs could withstand the force expected during deorbiting manoeuvres after impact with Al H/C panels. A parametric simulation comparing the diameter of conical tips with ballistic limits showed a good agreement with the predictions of De Marre's formula for normal impact. This suggests that the ballistic limit of plates impacted by conical projectiles can be successfully extrapolated with limited

  8. Meeting the Grand Challenge of Protecting Astronauts Health: Electrostatic Active Space Radiation Shielding for Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Tripathi, Ram K.

    2016-01-01

    This report describes the research completed during 2011 for the NASA Innovative Advanced Concepts (NIAC) project. The research is motivated by the desire to safely send humans in deep space missions and to keep radiation exposures within permitted limits. To this end current material shielding, developed for low earth orbit missions, is not a viable option due to payload and cost penalties. The active radiation shielding is the path forward for such missions. To achieve active space radiation shielding innovative large lightweight gossamer space structures are used. The goal is to deflect enough positive ions without attracting negatively charged plasma and to investigate if a charged Gossamer structure can perform charge deflections without significant structural instabilities occurring. In this study different innovative configurations are explored to design an optimum active shielding. In addition, to establish technological feasibility experiments are performed with up to 10kV of membrane charging, and an electron flux source with up to 5keV of energy and 5mA of current. While these charge flux energy levels are much less than those encountered in space, the fundamental coupled interaction of charged Gossamer structures with the ambient charge flux can be experimentally investigated. Of interest are, will the EIMS remain inflated during the charge deflections, and are there visible charge flux interactions. Aluminum coated Mylar membrane prototype structures are created to test their inflation capability using electrostatic charging. To simulate the charge flux, a 5keV electron emitter is utilized. The remaining charge flux at the end of the test chamber is measured with a Faraday cup mounted on a movable boom. A range of experiments with this electron emitter and detector were performed within a 30x60cm vacuum chamber with vacuum environment capability of 10-7 Torr. Experiments are performed with the charge flux aimed at the electrostatically inflated

  9. Transcriptional Regulation by the Short-Chain Fatty Acyl Coenzyme A Regulator (ScfR) PccR Controls Propionyl Coenzyme A Assimilation by Rhodobacter sphaeroides

    PubMed Central

    Carter, Michael S.

    2015-01-01

    ABSTRACT Propionyl coenzyme A (propionyl-CoA) assimilation by Rhodobacter sphaeroides proceeds via the methylmalonyl-CoA pathway. The activity of the key enzyme of the pathway, propionyl-CoA carboxylase (PCC), was upregulated 20-fold during growth with propionate compared to growth with succinate. Because propionyl-CoA is an intermediate in acetyl-CoA assimilation via the ethylmalonyl-CoA pathway, acetate growth also requires the methylmalonyl-CoA pathway. PCC activities were upregulated 8-fold in extracts of acetate-grown cells compared to extracts of succinate-grown cells. The upregulation of PCC activities during growth with propionate or acetate corresponded to increased expression of the pccB gene, which encodes a subunit of PCC. PccR (RSP_2186) was identified to be a transcriptional regulator required for the upregulation of pccB transcript levels and, consequently, PCC activity: growth substrate-dependent regulation was lost when pccR was inactivated by an in-frame deletion. In the pccR mutant, lacZ expression from a 215-bp plasmid-borne pccB upstream fragment including 27 bp of the pccB coding region was also deregulated. A loss of regulation as a result of mutations in the conserved motifs TTTGCAAA-X4-TTTGCAAA in the presence of PccR allowed the prediction of a possible operator site. PccR, together with homologs from other organisms, formed a distinct clade within the family of short-chain fatty acyl coenzyme A regulators (ScfRs) defined here. Some members from other clades within the ScfR family have previously been shown to be involved in regulating acetyl-CoA assimilation by the glyoxylate bypass (RamB) or propionyl-CoA assimilation by the methylcitrate cycle (MccR). IMPORTANCE Short-chain acyl-CoAs are intermediates in essential biosynthetic and degradative pathways. The regulation of their accumulation is crucial for appropriate cellular function. This work identifies a regulator (PccR) that prevents the accumulation of propionyl-CoA by controlling

  10. The INAF contribution to the ASI Space Debris program: observational activities.

    NASA Astrophysics Data System (ADS)

    Pupillo, G.; Salerno, E.; Bartolini, M.; Di Martino, M.; Mattana, A.; Montebugnoli, S.; Portelli, C.; Pluchino, S.; Schillirò, F.; Konovalenko, A.; Nabatov, A.; Nechaeva, M.

    Space debris are man made objects orbiting around Earth that pose a serious hazard for both present and future human activities in space. Since 2007 the Istituto Nazionale di Astrofisica (INAF) carried out a number of radar campaigns in the framework of the ASI ``Space Debris'' program. The observations were performed by using bi- and multi-static radars, composed of the INAF 32-m Italian radiotelescopes located at Medicina and Noto (used as receivers) and the 70-m parabolic antenna at Evpatoria (Ukraine) used as transmitter. The 32 m Ventspils antenna in Latvia also participated in the last campaign at the end of June 2010. Several kinds of objects in various orbital regions (radar calibrators, rocket upper stages, debris of different sizes) were observed and successfully detected. Some unknown objects were also discovered in LEO during the beam-park sessions. In this paper we describe some results of the INAF-ASI space debris research activity.

  11. Can we predict SPEs before solar surface events? For the safety operation of manned space activities-

    NASA Astrophysics Data System (ADS)

    Tomita, F.

    It is foregone conclusion that human activities in space will become more varied and more frequent as we move through the 21st century. Space tourism is now becoming practical realities, and manned Moon base or manned mission to Mars is also now considered feasible. For the safety operations of these manned space activities, the prediction of the Solar energetic Particle Events (SPEs) around the manned missions is one of the most important requisite. A typical SPE will start at 1 AU after a few tens of minutes when we identify the monstrous event near the solar surface by the observations of the peak flux and structure of the X-ray event, and/or brightness and structure of the coronal mass ejection (CME) / flare, and/or special spectral type of solar radio bursts. Consequently, it takes a few hours to reach maximum level. This maximum SPE level is sometimes lethal for the aurora watching space tourists, out-door activities at the Moon base, and extra vehicular activities during Mars explorations. The lead-time of about 2.5 hour or less for lethal SPEs may not be safe enough for future manned space activities. For our children and ground-children, we have to discover most reliable precursors of CME / flare, or think out the most practical prediction tools that are faster than the speed of light.

  12. Thermodynamics of polymer nematics described with a worm-like chain model: particle-based simulations and SCF theory calculations

    NASA Astrophysics Data System (ADS)

    Greco, Cristina; Yiang, Ying; Kremer, Kurt; Chen, Jeff; Daoulas, Kostas

    Polymer liquid crystals, apart from traditional applications as high strength materials, are important for new technologies, e.g. Organic Electronics. Their studies often invoke mesoscale models, parameterized to reproduce thermodynamic properties of the real material. Such top-down strategies require advanced simulation techniques, predicting accurately the thermodynamics of mesoscale models as a function of characteristic features and parameters. Here a recently developed model describing nematic polymers as worm-like chains interacting with soft directional potentials is considered. We present a special thermodynamic integration scheme delivering free energies in particle-based Monte Carlo simulations of this model, avoiding thermodynamic singularities. Conformational and structural properties, as well as Helmholtz free energies are reported as a function of interaction strength. They are compared with state-of-art SCF calculations invoking a continuum analog of the same model, demonstrating the role of liquid-packing and fluctuations.

  13. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 9 2012-04-01 2012-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this...

  14. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 9 2013-04-01 2013-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this...

  15. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 9 2014-04-01 2014-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this...

  16. 14 CFR 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. 1266.104... LIABILITY § 1266.104 Cross-waiver of liability for launch agreements for science or space exploration... cross-waiver of liability between the parties to agreements for NASA's science or space...

  17. 14 CFR 1266.102 - Cross-waiver of liability for agreements for activities related to the International Space Station.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... exploration, exploitation, and use of outer space through the International Space Station (ISS). The IGA... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Cross-waiver of liability for agreements for activities related to the International Space Station. 1266.102 Section 1266.102 Aeronautics...

  18. 14 CFR 1266.102 - Cross-waiver of liability for agreements for activities related to the International Space Station.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... exploration, exploitation, and use of outer space through the International Space Station (ISS). The IGA... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Cross-waiver of liability for agreements for activities related to the International Space Station. 1266.102 Section 1266.102 Aeronautics...

  19. 14 CFR 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. 1266.104... LIABILITY § 1266.104 Cross-waiver of liability for launch agreements for science or space exploration... cross-waiver of liability between the parties to agreements for NASA's science or space...

  20. 14 CFR 1266.102 - Cross-waiver of liability for agreements for activities related to the International Space Station.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... exploration, exploitation, and use of outer space through the International Space Station (ISS). The IGA... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Cross-waiver of liability for agreements for activities related to the International Space Station. 1266.102 Section 1266.102 Aeronautics...

  1. 14 CFR 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. 1266.104... LIABILITY § 1266.104 Cross-waiver of liability for launch agreements for science or space exploration... cross-waiver of liability between the parties to agreements for NASA's science or space...

  2. 14 CFR 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. 1266.104... LIABILITY § 1266.104 Cross-waiver of liability for launch agreements for science or space exploration... cross-waiver of liability between the parties to agreements for NASA's science or space...

  3. 14 CFR 1266.102 - Cross-waiver of liability for agreements for activities related to the International Space Station.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... exploration, exploitation, and use of outer space through the International Space Station (ISS). The IGA... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Cross-waiver of liability for agreements for activities related to the International Space Station. 1266.102 Section 1266.102 Aeronautics and...

  4. Communication: DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)

    SciTech Connect

    Wouters, Sebastian Van Speybroeck, Veronique; Van Neck, Dimitri; Bogaerts, Thomas; Van Der Voort, Pascal

    2014-06-28

    We use CHEMPS2, our free open-source spin-adapted implementation of the density matrix renormalization group (DMRG) [S. Wouters, W. Poelmans, P. W. Ayers, and D. Van Neck, Comput. Phys. Commun. 185, 1501 (2014)], to study the lowest singlet, triplet, and quintet states of the oxo-Mn(Salen) complex. We describe how an initial approximate DMRG calculation in a large active space around the Fermi level can be used to obtain a good set of starting orbitals for subsequent complete-active-space or DMRG self-consistent field calculations. This procedure mitigates the need for a localization procedure, followed by a manual selection of the active space. Per multiplicity, the same active space of 28 electrons in 22 orbitals (28e, 22o) is obtained with the 6-31G{sup *}, cc-pVDZ, and ANO-RCC-VDZP basis sets (the latter with DKH2 scalar relativistic corrections). Our calculations provide new insight into the electronic structure of the quintet.

  5. MNF, an ankyrin repeat protein of myxoma virus, is part of a native cellular SCF complex during viral infection.

    PubMed

    Blanié, Sophie; Gelfi, Jacqueline; Bertagnoli, Stéphane; Camus-Bouclainville, Christelle

    2010-01-01

    Myxoma virus (MYXV), a member of the Poxviridae family, is the agent responsible for myxomatosis, a fatal disease in the European rabbit (Oryctolagus cuniculus). Like all poxviruses, MYXV is known for encoding multiple proteins that regulate cellular signaling pathways. Among them, four proteins share the same ANK/PRANC structure: M148R, M149R, MNF (Myxoma Nuclear factor) and M-T5, all of them described as virulence factors. This family of poxvirus proteins, recently identified, has drawn considerable attention for its potential role in modulating the host ubiquitin-proteasome system during viral infection. To date, many members of this novel protein family have been shown to interact with SCF components, in vitro. Here, we focus on MNF gene, which has been shown to express a nuclear protein presenting nine ANK repeats, one of which has been identified as a nuclear localization signal. In transfection, MNF has been shown to colocalise with the transcription factor NF-kappaB in the nucleus of TNFalpha-stimulated cells. Functionally, MNF is a critical virulence factor since its deletion generates an almost apathogenic virus. In this study, to pursue the investigation of proteins interacting with MNF and of its mechanism of action, we engineered a recombinant MYXV expressing a GFP-linked MNF under the control of MNF native promoter. Infection of rabbits with MYXV-GFPMNF recombinant virus provided the evidence that the GFP fusion does not disturb the main function of MNF. Hence, cells were infected with MYXV-GFPMNF and immunoprecipitation of the GFPMNF fusion protein was performed to identify MNF's partners. For the first time, endogenous components of SCF (Cullin-1 and Skp1) were co-precipitated with an ANK myxoma virus protein, expressed in an infectious context, and without over-expression of any protein. PMID:20211013

  6. Smart SPHERES: A Telerobotic Free-Flyer for Intravehicular Activities in Space

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Micire, Mark J.; Morse, Ted; Park, Eric; Provencher, Chris; To, Vinh; Wheeler, D. W.; Mittman, David; Torres, R. Jay; Smith, Ernest

    2013-01-01

    Smart SPHERES is a prototype free-flying space robot based on the SPHERES platform. Smart SPHERES can be remotely operated by astronauts inside a spacecraft, or by mission controllers on the ground. We developed Smart SPHERES to perform a variety of intravehicular activities (IVA), such as operations inside the International Space Station (ISS). These IVA tasks include environmental monitoring surveys (radiation, sound levels, etc.), inventory, and mobile camera work. In this paper, we first discuss the motivation for free-flying space robots. We then describe the development of the Smart SPHERES prototype, including avionics, software, and data communications. Finally, we present results of initial flight tests on-board the ISS.

  7. Smart SPHERES: A Telerobotic Free-Flyer for Intravehicular Activities in Space

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Micire, Mark J.; Morse, Ted; Park, Eric; Provencher, Chris

    2013-01-01

    Smart SPHERES is a prototype free-flying space robot based on the SPHERES platform. Smart SPHERES can be remotely operated by astronauts inside a spacecraft, or by mission controllers on the ground. We developed Smart SPHERES to perform a variety of intravehicular activities (IVA), such as operations inside the International Space Station (ISS). These IVA tasks include environmental monitoring surveys (radiation, sound levels, etc.), inventory, and mobile camera work. In this paper, we first discuss the motivation for free- flying space robots. We then describe the development of the Smart SPHERES prototype, including avionics, software, and data communications. Finally, we present results of initial flight tests on-board the ISS.

  8. Analyses of space environment effects on active fiber optic links orbited aboard the LDEF

    NASA Technical Reports Server (NTRS)

    Taylor, Edward W.; Monarski, T. W.; Berry, J. N.; Sanchez, A. D.; Padden, R. J.; Chapman, S. P.

    1993-01-01

    The results of the 'Preliminary Analysis of WL Experiment no. 701, Space Environment Effects on Operating Fiber Optic Systems,' is correlated with space simulated post retrieval terrestrial studies performed on the M0004 experiment. Temperature cycling measurements were performed on the active optical data links for the purpose of assessing link signal to noise ratio and bit error rate performance some 69 months following the experiment deployment in low Earth orbit. The early results indicate a high correlation between pre-orbit, orbit, and post-orbit functionality of the first known and longest space demonstration of operating fiber optic systems.

  9. Active control synthesis for flexible space structures excited by persistent disturbances

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Gonzalez, Marcelo

    1990-01-01

    Both classical and state-space synthesis methods for active control of flexible space structures in the presence of persistent disturbances are presented. The methods exploit the so-called internal model principle for asymptotic disturbance rejection. A generic example of flexible space structures is used to illustrate the simplicity of the proposed design methodologies. The concept of a disturbance rejection filter dipole is introduced from a classical control viewpoint. It is shown that the proposed design methods will invariably make use of non-minimum-phase compensation for a class of noncolocated control problems. The need for tradeoffs between performance and parameter robustness is discussed.

  10. Propulsion/ASME Rocket-Based Combined Cycle Activities in the Advanced Space Transportation Program Office

    NASA Technical Reports Server (NTRS)

    Hueter, Uwe; Turner, James

    1998-01-01

    NASA's Office Of Aeronautics and Space Transportation Technology (OASTT) has establish three major coals. "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center in Huntsville,Ala. focuses on future space transportation technologies under the "Access to Space" pillar. The Advanced Reusable Technologies (ART) Project, part of ASTP, focuses on the reusable technologies beyond those being pursued by X-33. The main activity over the past two and a half years has been on advancing the rocket-based combined cycle (RBCC) technologies. In June of last year, activities for reusable launch vehicle (RLV) airframe and propulsion technologies were initiated. These activities focus primarily on those technologies that support the year 2000 decision to determine the path this country will take for Space Shuttle and RLV. In February of this year, additional technology efforts in the reusable technologies were awarded. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion. Aerojet, Boeing-Rocketdyne and Pratt & Whitney were selected for a two-year period to design, build and ground test their RBCC engine concepts. In addition, ASTROX, Pennsylvania State University (PSU) and University of Alabama in Huntsville also conducted supporting activities. The activity included ground testing of components (e.g., injectors, thrusters, ejectors and inlets) and integrated flowpaths. An area that has caused a large amount of difficulty in the testing efforts is the means of initiating the rocket combustion process. All three of the prime contractors above were using silane (SiH4) for ignition of the thrusters. This follows from the successful use of silane in the NASP program for scramjet ignition. However, difficulties were immediately encountered when silane (an 80/20 mixture of hydrogen/silane) was used for rocket

  11. Functional requirements document for the Earth Observing System Data and Information System (EOSDIS) Scientific Computing Facilities (SCF) of the NASA/MSFC Earth Science and Applications Division, 1992

    NASA Technical Reports Server (NTRS)

    Botts, Michael E.; Phillips, Ron J.; Parker, John V.; Wright, Patrick D.

    1992-01-01

    Five scientists at MSFC/ESAD have EOS SCF investigator status. Each SCF has unique tasks which require the establishment of a computing facility dedicated to accomplishing those tasks. A SCF Working Group was established at ESAD with the charter of defining the computing requirements of the individual SCFs and recommending options for meeting these requirements. The primary goal of the working group was to determine which computing needs can be satisfied using either shared resources or separate but compatible resources, and which needs require unique individual resources. The requirements investigated included CPU-intensive vector and scalar processing, visualization, data storage, connectivity, and I/O peripherals. A review of computer industry directions and a market survey of computing hardware provided information regarding important industry standards and candidate computing platforms. It was determined that the total SCF computing requirements might be most effectively met using a hierarchy consisting of shared and individual resources. This hierarchy is composed of five major system types: (1) a supercomputer class vector processor; (2) a high-end scalar multiprocessor workstation; (3) a file server; (4) a few medium- to high-end visualization workstations; and (5) several low- to medium-range personal graphics workstations. Specific recommendations for meeting the needs of each of these types are presented.

  12. Streamlined design and self reliant hardware for active control of precision space structures

    NASA Technical Reports Server (NTRS)

    Hyland, David C.; King, James A.; Phillips, Douglas J.

    1994-01-01

    Precision space structures may require active vibration control to satisfy critical performance requirements relating to line-of-sight pointing accuracy and the maintenance of precise, internal alignments. In order for vibration control concepts to become operational, it is necessary that their benefits be practically demonstrated in large scale ground-based experiments. A unique opportunity to carry out such demonstrations on a wide variety of experimental testbeds was provided by the NASA Control-Structure Integration (CSI) Guest Investigator (GI) Program. This report surveys the experimental results achieved by the Harris Corporation GI team on both Phases 1 and 2 of the program and provides a detailed description of Phase 2 activities. The Phase 1 results illustrated the effectiveness of active vibration control for space structures and demonstrated a systematic methodology for control design, implementation test. In Phase 2, this methodology was significantly streamlined to yield an on-site, single session design/test capability. Moreover, the Phase 2 research on adaptive neural control techniques made significant progress toward fully automated, self-reliant space structure control systems. As a further thrust toward productized, self-contained vibration control systems, the Harris Phase II activity concluded with experimental demonstration of new vibration isolation hardware suitable for a wide range of space-flight and ground-based commercial applications.The CSI GI Program Phase 1 activity was conducted under contract NASA1-18872, and the Phase 2 activity was conducted under NASA1-19372.

  13. Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus)

    PubMed Central

    Vas, Judit; Andersen, Inger Lise

    2015-01-01

    Very little is known about the spacing behaviour in social groups of domestic goats (Capra hircus) in the farm environment. In this experiment, we studied interindividual distances, movement patterns and activity budgets in pregnant goats housed at three different densities. Norwegian dairy goats were kept in stable social groups of six animals throughout pregnancy at 1, 2 or 3 m2 per individual and their spacing behaviours (i.e. distance travelled, nearest and furthest neighbour distance) and activity budgets (e.g. resting, feeding, social activities) were monitored. Observations were made in the first, second and last thirds of pregnancy in the mornings, at noon and in the afternoons of each of these phases (4.5 hours per observation period). The findings show that goats held at animal densities of 2 and 3 m2 moved longer distances when they had more space per animal and kept larger nearest and furthest neighbour distances when compared to the 1 m2 per animal density. Less feeding activity was observed at the high animal density compared to the medium and low density treatments. The phase of gestation also had an impact on almost all behavioural variables. Closer to parturition, animals moved further distances and the increase in nearest and furthest neighbour distance was more pronounced at the lower animal densities. During the last period of gestation, goats spent less time feeding and more on resting, social behaviours and engaging in other various activities. Our data suggest that more space per goat is needed for goats closer to parturition than in the early gestation phase. We concluded that in goats spacing behaviour is density-dependent and changes with stages of pregnancy and activities. Finally, the lower density allowed animals to express individual preferences regarding spacing behaviour which is important in ensuring good welfare in a farming situation. PMID:26657240

  14. A review of UK space activity and historiography, 1957-2007

    NASA Astrophysics Data System (ADS)

    Millard, Douglas

    2010-04-01

    In over 50 years the United Kingdom has designed, built, launched, operated or otherwise contributed to hundreds of spacecraft and space missions. Its scientists, engineers and officials have carved centres of astronautical excellence around the country, participated in a great number of international space programmes and missions and played a leading role in the establishment of the world's main pan-national space agency (ESA) and its two precursors, the European Launcher Development Organisation (ELDO) and the European Space Research Organization (ESRO). With its Skylark sounding rocket launch of November 1957 the UK was one of the first nations to gather new scientific data as part of the International Geophysical Year. Fifty years on, the UK is an enthusiastic supporter of the Global Exploration Strategy with major commitments to future missions to the moon and to the Mars that exploit the nation's expertise in small satellite and planetary robot technology. And while such mission involvement takes UK space technologies out into the solar system as never before the nation continues to excel in Earth orbit with its development and manufacture of large, increasingly powerful telecommunications satellites. The UK's space heritage and its ongoing and directed activities are rich and productive. And yet—the representation of UK space endeavour is all too often skewed—misleading and unduly pejorative: '…British space…more romance than reality.' Why does such partisan commentary occur and why has such an attitude prevailed for so long? This paper seeks some answers by reviewing UK space activity and its historiography in the wider and global context of astronautics between 1957 and 2007. In Praise of…the British Space Programme, The Guardian Newspaper, March 4th, 2008.

  15. Cdc34 C-terminal tail phosphorylation regulates Skp1/cullin/F-box (SCF)-mediated ubiquitination and cell cycle progression

    PubMed Central

    Sadowski, Martin; Mawson, Amanda; Baker, Rohan; Sarcevic, Boris

    2007-01-01

    The ubiquitin-conjugating enzyme Cdc34 (cell division cycle 34) plays an essential role in promoting the G1–S-phase transition of the eukaryotic cell cycle and is phosphorylated in vivo. In the present study, we investigated if phosphorylation regulates Cdc34 function. We mapped the in vivo phosphorylation sites on budding yeast Cdc34 (yCdc34; Ser207 and Ser216) and human Cdc34 (hCdc34 Ser203, Ser222 and Ser231) to serine residues in the acidic tail domain, a region that is critical for Cdc34's cell cycle function. CK2 (protein kinase CK2) phosphorylates both yCdc34 and hCdc34 on these sites in vitro. CK2-mediated phosphorylation increased yCdc34 ubiquitination activity towards the yeast Saccharomyces cerevisiae Sic1 in vitro, when assayed in the presence of its cognate SCFCdc4 E3 ligase [where SCF is Skp1 (S-phase kinase-associated protein 1)/cullin/F-box]. Similarly, mutation of the yCdc34 phosphorylation sites to alanine, aspartate or glutamate residues altered Cdc34–SCFCdc4-mediated Sic1 ubiquitination activity. Similar results were obtained when yCdc34's ubiquitination activity was assayed in the absence of SCFCdc4, indicating that phosphorylation regulates the intrinsic catalytic activity of Cdc34. To evaluate the in vivo consequences of altered Cdc34 activity, wild-type yCdc34 and the phosphosite mutants were introduced into an S. cerevisiae cdc34 deletion strain and, following synchronization in G1-phase, progression through the cell cycle was monitored. Consistent with the increased ubiquitination activity in vitro, cells expressing the phosphosite mutants with higher catalytic activity exhibited accelerated cell cycle progression and Sic1 degradation. These studies demonstrate that CK2-mediated phosphorylation of Cdc34 on the acidic tail domain stimulates Cdc34–SCFCdc4 ubiquitination activity and cell cycle progression. PMID:17461777

  16. The law applicable to the use of space for commercial activities

    NASA Technical Reports Server (NTRS)

    Hosenball, S. N.

    1983-01-01

    The general principles of space law that have an impact on commercial space activities are discussed. The Outer Space Treaty guaranteed the right of private enterprise in space, with jurisdiction over the participating parties residing in the country of origin. The liability for damages caused to a third party is also assigned to the country of origin. Government consent is necessary in the U.S. before a private firm is permitted to launch an object into space, with the relevant statute sections being part of the Arms Export Control Act; launches are legally treated as exports. FAA regulations define the safe area and flight conditions that must be satisfied for a private launch, although NASA, in the 1958 act which formed the agency, potentialy has the power to regulate space launch activities. The DoD must be notified of any launches in order to notify the U.S.S.R., filings must be made with the Bureau of Alcohol, Tobacco, and Firearms, and fees must be paid to the IRS. It is presently U.S. government policy to encourage and facilitate private sector development of commercial launch services.

  17. Task-specific stability in muscle activation space during unintentional movements.

    PubMed

    Falaki, Ali; Towhidkhah, Farzad; Zhou, Tao; Latash, Mark L

    2014-11-01

    We used robot-generated perturbations applied during position-holding tasks to explore stability of induced unintentional movements in a multidimensional space of muscle activations. Healthy subjects held the handle of a robot against a constant bias force and were instructed not to interfere with hand movements produced by changes in the external force. Transient force changes were applied leading to handle displacement away from the initial position and then back toward the initial position. Intertrial variance in the space of muscle modes (eigenvectors in the muscle activations space) was quantified within two subspaces, corresponding to unchanged handle coordinate and to changes in the handle coordinate. Most variance was confined to the former subspace in each of the three phases of movement, the initial steady state, the intermediate position, and the final steady state. The same result was found when the changes in muscle activation were analyzed between the initial and final steady states. Changes in the dwell time between the perturbation force application and removal led to different final hand locations undershooting the initial position. The magnitude of the undershot scaled with the dwell time, while the structure of variance in the muscle activation space did not depend on the dwell time. We conclude that stability of the hand coordinate is ensured during both intentional and unintentional actions via similar mechanisms. Relative equifinality in the external space after transient perturbations may be associated with varying states in the redundant space of muscle activations. The results fit a hierarchical scheme for the control of voluntary movements with referent configurations and redundant mapping between the levels of the hierarchy. PMID:25092272

  18. Hands-on Activities Tie Science Ed Standards to Space Weather on Windows to the Universe

    NASA Astrophysics Data System (ADS)

    Russell, R. M.; Johnson, R. M.

    2008-12-01

    The Windows to the Universe project includes a large web site with extensive user traffic as well as program of professional development workshops for teachers. In the past 5 years we have conducted 18 workshops dedicated exclusively to space weather and magnetism serving 573 total attendees. This talk describes our pedagogical approach of blending hands-on activities, covering basic concepts of magnetism, with visually- rich presentations of space weather topics in order to encourage teachers to incorporate space weather themes into their classroom teaching. Basic understanding of physical science themes of magnetism, electricity, forces, and motion are well represented in science education standards. Hands-on activities touching upon these themes simultaneously fulfill a teacher's need to cover topics in the standards and prepare students to comprehend more abstract representations of more complex systems relevant to space weather. Simply put, a student who has traced field lines around a bar magnet using a simple magnetometer is much better equipped to comprehend portrayals (images and animations) of complex magnetic fields associated with space weather phenomena. Thus, one of our main approaches to space weather education has been to encourage students to explore basic physical science concepts (as outlined in education standards) via hands-on activities and then to link those simple principles to more complex and visually captivating representations of space weather phenomena. We employ two other approaches to making the connections between standards-based themes that teachers must cover and concepts that are key to the study of space weather. The first is to tap heavily into "societal impacts" elements of education standards. Space weather presents numerous instances in which phenomena of scientific interest - such as radiation hazards to spacecraft and astronauts, communications disruptions, and surges in electrical power systems - have implications for

  19. Large segmented UV-optical space telescope using a Hybrid Sensor Active Control (HSAC) architecture

    NASA Astrophysics Data System (ADS)

    Feinberg, Lee D.; Dean, Bruce; Hyde, Tupper; Oegerle, Bill; Bolcar, Matthew R.; Smith, J. Scott

    2009-08-01

    Future large UV-optical space telescopes offer new and exciting windows of scientific parameter space. These telescopes can be placed at L2 and borrow heavily from the James Webb Space Telescope (JWST) heritage. For example, they can have similar deployment schemes, hexagonal mirrors, and use Wavefront Sensing and Control (WFSC) technologies developed for JWST. However, a UV-optical telescope requires a 4x improvement in wavefront quality over JWST to be diffraction-limited at 500 nm. Achieving this tolerance would be difficult using a passive thermal architecture such as the one employed on JWST. To solve this problem, our team has developed a novel Hybrid Sensor Active Control (HSAC) architecture that provides a cost effective approach to building a segmented UV-optical space telescope. In this paper, we show the application of this architecture to the ST-2020 mission concept and summarize the technology development requirements.

  20. NASA Crew Personal Active Dosimeters (CPADs): Leveraging Novel Terrestrial Personal Radiation Monitoring Capabilities for Space Exploration

    NASA Technical Reports Server (NTRS)

    Leitgab, Martin; Semones, Edward; Lee, Kerry

    2016-01-01

    The NASA Space Radiation Analysis Group (SRAG) is developing novel Crew Personal Active Dosimeters (CAPDs) for upcoming crewed space exploration missions and beyond. To reduce the resource footprint of the project a COTS dosimeter base is used for the development of CPADs. This base was identified from evaluations of existing COTS personal dosimeters against the concept of operations of future crewed missions and tests against detection requirements for radiation characteristic of the space environment. CPADs exploit operations efficiencies from novel features for space flight personal dosimeters such as real-time dose feedback, and autonomous measuring and data transmission capabilities. Preliminary CPAD design, results of radiation testing and aspects of operational integration will be presented.

  1. Quantum-classical transition and quantum activation of ratchet currents in the parameter space.

    PubMed

    Beims, M W; Schlesinger, M; Manchein, C; Celestino, A; Pernice, A; Strunz, W T

    2015-05-01

    The quantum ratchet current is studied in the parameter space of the dissipative kicked rotor model coupled to a zero-temperature quantum environment. We show that vacuum fluctuations blur the generic isoperiodic stable structures found in the classical case. Such structures tend to survive when a measure of statistical dependence between the quantum and classical currents are displayed in the parameter space. In addition, we show that quantum fluctuations can be used to overcome transport barriers in the phase space. Related quantum ratchet current activation regions are spotted in the parameter space. Results are discussed based on quantum, semiclassical, and classical calculations. While the semiclassical dynamics involves vacuum fluctuations, the classical map is driven by thermal noise. PMID:26066230

  2. ActiveSpaces on the grid: The construction of advanced visualization and interaction environments

    SciTech Connect

    Childers, L.; Disz, T.; Hereld, M.; Hudson, R.; Judson, I.; Olson, R.; Papka, M. E.; Paris, J.; Stevens, R.

    2000-07-24

    The Futures Lab group at Argonne National Laboratory and the University of Chicago are designing, building, and evaluating a new type of interactive computing environment that couples in a deep way the concepts of direct manipulation found in virtual reality with the richness and variety of interactive devices found in ubiquitous computing. This environment provides the interactivity and collaboration support of teleimmersive environments with the exibility and availability of desktop collaboration tools. The authors call these environments ActiveSpaces. An ActiveSpace is a physical domain that has been augmented with multiscale multiscreen displays, environment-specific and device-specific sensors, body and object trackers, human-input and instrument-input interfaces, streaming audio and video capture devices, and force feedback devices--and has then been connected to other such spaces via the Grid.

  3. The 1859 Solar-Terrestrial Disturbance And the Current Limits of Extreme Space Weather Activity

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.; Svalgaard, L.

    2004-10-01

    It is generally appreciated that the September 1859 solar-terrestrial disturbance, the first recognized space weather event, was exceptionally large. How large and how exceptional? To answer these questions, we compiled rank order lists of the various measures of solar-induced disturbance for events from 1859 to the present. The parameters considered included: magnetic crochet amplitude, solar energetic proton fluence (McCracken et al., 2001a), Sun-Earth disturbance transit time, geomagnetic storm intensity, and low-latitude auroral extent. While the 1859 event has close rivals or superiors in each of the above categories of space weather activity, it is the only documented event of the last ˜150 years that appears at or near the top of all of the lists. Taken together, the top-ranking events in each of the disturbance categories comprise a set of benchmarks for extreme space weather activity.

  4. Spaced-antenna wind estimation using an X-band active phased-array weather radar

    NASA Astrophysics Data System (ADS)

    Venkatesh, Vijay

    Over the past few decades, several single radar methods have been developed to probe the kinematic structure of storms. All these methods trade angular-resolution to retrieve the wind-field. To date, the spaced-antenna method has been employed for profiling the ionosphere and the precipitation free lower atmosphere. This work focuses on applying the spaced-antenna method on an X-band active phased-array radar for high resolution horizontal wind-field retrieval from precipitation echoes. The ability to segment the array face into multiple displaced apertures allows for flexible spaced-antenna implementations. The methodology employed herein comprises of Monte-Carlo simulations to optimize the spaced-antenna system design and analysis of real data collected with the designed phased-array system. The contribution that underpins this dissertation is the demonstration of qualitative agreement between spaced-antenna and Doppler beam swinging retrievals based on real data. First, simulations of backscattered electric fields at the antenna array elements are validated using theoretical expressions. Based on the simulations, the degrees of freedom in the spaced-antenna system design are optimized for retrieval of mean baseline wind. We show that the designed X-band spaced-antenna system has lower retrieval uncertainty than the existing S-band spaced-antenna implementation on the NWRT. This is because of the flexibility to synthesize small overlapping apertures and the ability to obtain statistically independent samples at a faster rate at X-band. We then demonstrate a technique to make relative phase-center displacement measurements based on simulations and real data from the phased-array spaced-antenna system. This simple method uses statistics of precipitation echoes and apriori beamwidth measurements to make field repeatable phase-center displacement measurements. Finally, we test the hypothesis that wind-field curvature effects are common to both the spaced-antenna and

  5. incurvata13, a Novel Allele of AUXIN RESISTANT6, Reveals a Specific Role for Auxin and the SCF Complex in Arabidopsis Embryogenesis, Vascular Specification, and Leaf Flatness1[W][OA

    PubMed Central

    Esteve-Bruna, David; Pérez-Pérez, José Manuel; Ponce, María Rosa; Micol, José Luis

    2013-01-01

    Auxin plays a pivotal role in plant development by modulating the activity of SCF ubiquitin ligase complexes. Here, we positionally cloned Arabidopsis (Arabidopsis thaliana) incurvata13 (icu13), a mutation that causes leaf hyponasty and reduces leaf venation pattern complexity and auxin responsiveness. We found that icu13 is a novel recessive allele of AUXIN RESISTANT6 (AXR6), which encodes CULLIN1, an invariable component of the SCF complex. Consistent with a role for auxin in vascular specification, the vascular defects in the icu13 mutant were accompanied by reduced expression of auxin transport and auxin perception markers in provascular cells. This observation is consistent with the expression pattern of AXR6, which we found to be restricted to vascular precursors and hydathodes in wild-type leaf primordia. AXR1, RELATED TO UBIQUITIN1-CONJUGATING ENZYME1, CONSTITUTIVE PHOTOMORPHOGENIC9 SIGNALOSOME5A, and CULLIN-ASSOCIATED NEDD8-DISSOCIATED1 participate in the covalent modification of CULLIN1 by RELATED TO UBIQUITIN. Hypomorphic alleles of these genes also display simple venation patterns, and their double mutant combinations with icu13 exhibited a synergistic, rootless phenotype reminiscent of that caused by loss of function of MONOPTEROS (MP), which forms an auxin-signaling module with BODENLOS (BDL). The phenotypes of double mutant combinations of icu13 with either a gain-of-function allele of BDL or a loss-of-function allele of MP were synergistic. In addition, a BDL:green fluorescent protein fusion protein accumulated in icu13, and BDL loss of function or MP overexpression suppressed the phenotype of icu13. Our results demonstrate that the MP-BDL module is required not only for root specification in embryogenesis and vascular postembryonic development but also for leaf flatness. PMID:23319550

  6. Looking Inside and Out: Perceptions of Physical Activity in Childcare Spaces

    ERIC Educational Resources Information Center

    Weinberger, Nanci; Butler, Allison G.; Schumacher, Phyllis

    2014-01-01

    This study addresses the need to better understand how providers' perceptions of indoor and outdoor childcare settings can set the stage for arranging play spaces to optimise children's moderate-to-vigorous physical play. Childcare providers' perceptions of the level of physical activity, safety, and quality that children experience…

  7. Mirror actively deformed and regulated for applications in space: design and performance

    NASA Astrophysics Data System (ADS)

    Laslandes, Marie; Hugot, Emmanuel; Ferrari, Marc; Hourtoule, Claire; Singer, Christian; Devilliers, Christophe; Lopez, Céline; Chazallet, Frédéric

    2013-09-01

    The need for both high quality images and lightweight structures is one of the main drivers in space telescope design. An efficient wavefront control system will become mandatory in future large observatories, retaining performance while relaxing specifications in the global system's stability. We present the mirror actively deformed and regulated for applications in space project, which aims to demonstrate the applicability of active optics for future space instrumentation. It has led to the development of a 24-actuator, 90-mm-diameter active mirror, able to compensate for large lightweight primary mirror deformations in the telescope's exit pupil. The correcting system has been designed for expected wavefront errors from 3-m-class lightweight primary mirrors, while also taking into account constraints for space use. Finite element analysis allowed an optimization of the system in order to achieve a precision of correction better than 10 nm rms. A dedicated testbed has been designed to fully characterize the integrated system performance in representative operating conditions. It is composed of: a telescope simulator, an active correction loop, a point spread function imager, and a Fizeau interferometer. All conducted tests demonstrated the correcting mirror performance and has improved this technology maturity to a TRL4.

  8. "Go Be a Writer": Intra-Activity with Materials, Time and Space in Literacy Learning

    ERIC Educational Resources Information Center

    Kuby, Candace R.; Rucker, Tara Gutshall; Kirchhofer, Jessica M.

    2015-01-01

    This article is based on research in a United States second-grade classroom during a multimodal literacy workshop. Observing students working with tissue paper, foam board, string, pipe cleaners and other materials, we asked how is intra-activity with materials, time and space influencing literacy learning in Room 203? While the research…

  9. Young Children's Literacy in the Activity Space of the Library: A Geosemiotic Investigation

    ERIC Educational Resources Information Center

    Nichols, Sue

    2011-01-01

    An ecological approach, emphasizing the importance of understanding multiple contexts for learning, underpins this study of libraries as activity spaces for young children's literacy participation. Five libraries serving a diversity of communities were the subject of ethnographic investigation incorporating participant observation, visual…

  10. Aeronautics and Space Report of the President, Fiscal Year 2002 Activities

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Fiscal Year (FY) 2002 brought advances on many fronts in support of NASAs new vision, announced by Administrator Sean OKeefe on April 12, to improve life here, to extend life to there, to find life beyond. NASA successfully carried out four Space Shuttle missions, including three to the International Space Station (ISS) and one servicing mission to the Hubble Space Telescope (HST). By the end of the fiscal year, humans had occupied the ISS continuously for 2 years. NASA also managed five expendable launch vehicle (ELV) missions and participated in eight international cooperative ELV launches. In the area of space science, two of the Great Observatories, the Hubble Space Telescope and the Chandra X-Ray Observatory, continued to make spectacular observations. The Mars Global Surveyor and Mars Odyssey carried out their mapping missions of the red planet in unprecedented detail. Among other achievements, the Near Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft made the first soft landing on an asteroid, and the Solar and Heliospheric Observatory (SOHO) monitored a variety of solar activity, including the largest sunspot observed in 10 years. The education and public outreach program stemming from NASAs space science missions continues to grow. In the area of Earth science, attention focused on completing the first Earth Observing Satellite series. Four spacecraft were successfully launched. The goal is to understand our home planet as a system, as well as how the global environment responds to change.

  11. Standardizing orbit planning, satellite operations, and communication activities that are affected by space weather

    NASA Astrophysics Data System (ADS)

    Tobiska, W.

    2007-12-01

    Precision satellite orbit determination, constellation station-keeping, debris avoidance, reentry timing, satellite subsystem performance and safety, and communication link enhancement are among the major technological activities that are affected by space weather. There are numerous applications being developed to mitigate space weather affects on these domains. However, the common language for information exchange still needs community attention. We report on progress towards a) providing applications and services that mitigate adverse effects caused by space weather and b) developing international standards for exchange of information. For applications and services, Space Environment Technologies (SET) has developed a) new solar indices that reduce 1-sigma uncertainty by 50 percent in atmosphere density calculations, b) new spacecraft surface charging characterizations, and c) new solar irradiances that capture solar flare effects on transionospheric communications. These solar products have been developed and tested for: 1) daily time resolution for historical, nowcast, and intermediate-term forecast periods (1-day granularity, 1-hour cadence, and 1-hour latency extending 4.5 months); 2) high time resolution for recent, nowcast, and short-term forecast periods (3-hour granularity, 1-hour cadence, and 1-hour latency extending 96 hours); and 3) precision time resolution for recent, current epoch, and near-term forecast periods (1-minute granularity, 2-minute cadence, and 5-minute latency extending 6 hours). These indices and solar irradiances are used for improving atmosphere density and ionosphere models' outputs and we describe specific case studies as well as coupled applications that serve space systems users in orbit planning, satellite operations, and communication activities. For standards, we report on the activities of ISO TC20/SC14/WG4, which has the authority to develop international standards related to the space environment.

  12. Space-Based Astronomy: An Educator Guide with Activities for Science, Mathematics, and Technology Education

    NASA Technical Reports Server (NTRS)

    Vogt, Gregory L.

    2001-01-01

    If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.

  13. Effects of Space Weather on Biomedical Parameters during the Solar Activity Cycles 23-24.

    PubMed

    Ragul'skaya, M V; Rudenchik, E A; Chibisov, S M; Gromozova, E N

    2015-06-01

    The results of long-term (1998-2012) biomedical monitoring of the biotropic effects of space weather are discussed. A drastic change in statistical distribution parameters in the middle of 2005 was revealed that did not conform to usual sinusoidal distribution of the biomedical data reflecting changes in the number of solar spots over a solar activity cycle. The dynamics of space weather of 2001-2012 is analyzed. The authors hypothesize that the actual change in statistical distributions corresponds to the adaptation reaction of the biosphere to nonstandard geophysical characteristics of the 24th solar activity cycle and the probable long-term decrease in solar activity up to 2067. PMID:26085362

  14. Overview of active methods for shielding spacecraft from energetic space radiation

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W. (Principal Investigator)

    2001-01-01

    During the 1960's and into the early 1970's, investigations were conducted related to the feasibility of using active radiation shielding methods, such as afforded by electromagnetic fields, as alternatives to passive, bulk material shielding to attenuate space radiations. These active concepts fall into four categories: (1) electrostatic fields; (2) plasma shields; (3) confined magnetic fields; and (4) unconfined magnetic fields. In nearly all of these investigations, consideration was given only to shielding against protons or electrons, or both. During the 1980's and 1990's there were additional studies related to proton shielding and some new studies regarding the efficacy of using active methods to shield from the high energy heavy ion (HZE particle) component of the galactic cosmic ray spectrum. In this overview, each concept category is reviewed and its applicability and limitations for the various types of space radiations are described. Recommendations for future research on this topic are made.

  15. Overview of active methods for shielding spacecraft from energetic space radiation.

    PubMed

    Townsend, L W

    2001-01-01

    During the 1960's and into the early 1970's, investigations were conducted related to the feasibility of using active radiation shielding methods, such as afforded by electromagnetic fields, as alternatives to passive, bulk material shielding to attenuate space radiations. These active concepts fall into four categories: (1) electrostatic fields; (2) plasma shields; (3) confined magnetic fields; and (4) unconfined magnetic fields. In nearly all of these investigations, consideration was given only to shielding against protons or electrons, or both. During the 1980's and 1990's there were additional studies related to proton shielding and some new studies regarding the efficacy of using active methods to shield from the high energy heavy ion (HZE particle) component of the galactic cosmic ray spectrum. In this overview, each concept category is reviewed and its applicability and limitations for the various types of space radiations are described. Recommendations for future research on this topic are made. PMID:11770543

  16. Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

    PubMed

    Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. PMID:26177621

  17. Office of Commercial Programs' research activities for Space Station Freedom utilization

    NASA Technical Reports Server (NTRS)

    Fountain, James A.

    1992-01-01

    One of the objectives of the Office of Commercial Programs (OCP) is to encourage, enable, and help implement space research which meets the needs of the U.S. industrial sector. This is done mainly through seventeen Centers for the Commercial Development of Space (CCDS's) which are located throughout the United States. The CCDS's are composed of members from U.S. companies, universities, and other government agencies. These Centers are presently engaged in industrial research in space using a variety of carriers to reach low Earth orbit. One of the goals is to produce a body of experience and knowledge that will allow U.S. industrial entities to make informed decisions regarding their participation in commercial space endeavors. A total of 32 items of payload hardware were built to date. These payloads have flown in space a total of 73 times. The carriers range from the KC-135 parabolic aircraft and expendable launch vehicles to the Space Shuttle. This range of carriers allows the experimenter to evolve payloads in complexity and cost by progressively extending the time in microgravity. They can start with a few seconds in the parabolic aircraft and go to several minutes on the rocket flights, before they progress to the complexities of manned flight on the Shuttle. Next year, two new capabilities will become available: COMET, an expendable-vehicle-launched experiment capsule that can carry experiments aloft for thirty days; and SPACEHAB, a new Shuttle borne module which will greatly add to the capability to accommodate small payloads. All of these commercial research activities and carrier capabilities are preparing the OCP to evolve those experiments that prove successful to Space Station Freedom. OCP and the CCDS's are actively involved in Space Station design and utilization planning and have proposed a set of experiments to be launched in 1996 and 1997. These experiments are to be conducted both internal and external to Space Station Freedom and will

  18. Conceptualization and measurement of environmental exposure in epidemiology: accounting for activity space related to daily mobility.

    PubMed

    Perchoux, Camille; Chaix, Basile; Cummins, Steven; Kestens, Yan

    2013-05-01

    A considerable body of literature has investigated how environmental exposures affect health through various pathways. These studies have generally adopted a common approach to define environmental exposures, focusing on the local residential environment, using census tracts or postcodes to delimit exposures. However, use of such administrative units may not be appropriate to evaluate contextual effets on health because they are generally not a 'true' representation of the environments to which individuals are exposed. Recent work has suggested that advances may be made if an activity-space approach is adopted. The present paper investigates how various disciplines may contribute to the refinement of the concept of activity space for use in health research. In particular we draw on seminal work in time geography, which provides a framework to describe individual behavior in space and time, and can help the conceptualization of activity space. In addition we review work in environmental psychology and social networks research, which provides insights on how people and places interact and offers new theories for improving the spatial definition of contextual exposures. PMID:23454664

  19. Activity of the sympathetic-adrenomedullary system in rats after space flight on the COSMOS biosatellites

    NASA Astrophysics Data System (ADS)

    Kvetňanský, R.; Vigaš, M.; Németh, Š.; Macho, L.; Tigranyan, R. A.

    The indicators of adrenomedullary activity (catecholamine content (CA) and the activity of the catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH)) were measured in the adrenal glands of rats living in a state of weightlessness for 18.5-19.5 days on board the biosatellites COSMOS 936 and COSMOS 1129. None of these indicators was significantly changed by space flight, neither in the group living in a state of weightlessness nor in the group living in a centrifuge on board the spacecraft and exposed to artificial gravity of 1 g (COSMOS 936). Animals exposed after space flight to repeated immobilization stress on Earth showed a significant decrease of adrenal adrenaline and an appreciable increase in adrenal TH activity compared to stressed animals which were not in space. These results suggest that a prolonged state of weightlessness during space flight does not by itself represent an intensive stressful stimulus for the adrenomedullary system but potentiates the response of cosmonauts to stress after return to Earth.

  20. Zero-g experiments with a He II active phase separator for space application

    NASA Technical Reports Server (NTRS)

    Denner, H. D.; Klipping, G.; Lueders, K.; Ruppert, U.; Stahnke, F.; Szuecs, Z.; Elleman, D.; Petrac, D.

    1984-01-01

    An active phase separator (APS) for temperature control of He II space cooling systems was tested in a zero-g environment during a series of parabolic flights on a NASA KC 135 aircraft. The APS provides for liquid-gas separation and features an annular gap, a downstream heat exchanger and an upstream ball closure. The apparatus was operated during acceleration and floating and in two different heat load situations. The tests confirmed that adequate mass flow rates could be maintained using a vacuum pump to simulate space vacuum and that residual liquid could be evaporated from the heat exchanger after closing a ball valve to seal off flows.

  1. Human Activity Behavior and Gesture Generation in Virtual Worlds for Long- Duration Space Missions. Chapter 8

    NASA Technical Reports Server (NTRS)

    Sierhuis, Maarten; Clancey, William J.; Damer, Bruce; Brodsky, Boris; vanHoff, Ron

    2007-01-01

    A virtual worlds presentation technique with embodied, intelligent agents is being developed as an instructional medium suitable to present in situ training on long term space flight. The system combines a behavioral element based on finite state automata, a behavior based reactive architecture also described as subsumption architecture, and a belief-desire-intention agent structure. These three features are being integrated to describe a Brahms virtual environment model of extravehicular crew activity which could become a basis for procedure training during extended space flight.

  2. 1,4-Diazabicyclo[2.2.2]octane-Promoted Aminotrifluoromethylthiolation of α,β-Unsaturated Carbonyl Compounds: N-Trifluoromethylthio-4-nitrophthalimide Acts as Both the Nitrogen and SCF3 Sources.

    PubMed

    Xiao, Qing; He, Qijie; Li, Juncheng; Wang, Jun

    2015-12-18

    A novel difunctionalization reaction is described. It uses N-trifluoromethylthio-4-nitrophthalimide as the reagent, which serves as both the nitrogen and SCF3 sources. In the presence of DABCO (1,4-diazabicyclo[2.2.2]octane), the nitrogen and SCF3 groups can be incorporated into α,β-unsaturated carbonyl compounds easily and give versatile β-amino ketones and esters in good yields. This difunctionalization reaction features mild reaction conditions, high atom-economy, and efficient access to α-SCF3 amino acids. PMID:26655102

  3. Task-discriminative space-by-time factorization of muscle activity

    PubMed Central

    Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien

    2015-01-01

    Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment. PMID:26217213

  4. Evaluation of radioisotope tracer and activation analysis techniques for contamination monitoring in space environment simulation chambers

    NASA Technical Reports Server (NTRS)

    Smathers, J. B.; Kuykendall, W. E., Jr.; Wright, R. E., Jr.; Marshall, J. R.

    1973-01-01

    Radioisotope measurement techniques and neutron activation analysis are evaluated for use in identifying and locating contamination sources in space environment simulation chambers. The alpha range method allows the determination of total contaminant concentration in vapor state and condensate state. A Cf-252 neutron activation analysis system for detecting oils and greases tagged with stable elements is described. While neutron activation analysis of tagged contaminants offers specificity, an on-site system is extremely costly to implement and provides only marginal detection sensitivity under even the most favorable conditions.

  5. The Production of Information for Genred Activity Spaces: Informational Motives and Consequences of the Environmental Impact Statement

    ERIC Educational Resources Information Center

    Bazerman, Charles; Little, Joseph; Chavkin, Teri

    2003-01-01

    Genres, although aligning people to joint activity and joint attention, shape the substantive material or information represented within the bounded space of the text. Each genre creates a space that prompts the production of particular kinds of information to populate that space. The National Environmental Policy Act of 1969 that mandated the…

  6. Helmet-mounted display and associated research activities recently conducted by the NASA Johnson Space Center

    NASA Astrophysics Data System (ADS)

    Marmolejo, Jose A.

    1994-06-01

    To enhance manned extravehicular activity (EVA) utilizing an extravehicular mobility unit (EMU)(i.e., a space suit and portable life support backpack), NASA has conducted research into implementing helmet mounted display (HMD) and related technology within its next generation of space suits. The NASA/Johnson Space Center has completed four feasibility development programs for the design and development of an EMU HMD, each resulting in the delivery of a binocular or biocular HMD breadboard unit utilizing conventional optical elements (i.e., glass lenses and beamsplitters) and/or holographic optics. Additional research into combining the use of voice recognition for astronaut 'hands- free' access to information via the HMD has also been conducted. Research conducted since 1983 will be summarized along with current shuttle EMU display enhancements. In addition, recommendations for the design of the next generation of displays for use within the EMU will be presented.

  7. Computer Analysis of Electromagnetic Field Exposure Hazard for Space Station Astronauts during Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.; Kelley, James S.; Panneton, Robert B.; Arndt, G. Dickey

    1995-01-01

    In order to estimate the RF radiation hazards to astronauts and electronics equipment due to various Space Station transmitters, the electric fields around the various Space Station antennas are computed using the rigorous Computational Electromagnetics (CEM) techniques. The Method of Moments (MoM) was applied to the UHF and S-band low gain antennas. The Aperture Integration (AI) method and the Geometrical Theory of Diffraction (GTD) method were used to compute the electric field intensities for the S- and Ku-band high gain antennas. As a result of this study, The regions in which the electric fields exceed the specified exposure levels for the Extravehicular Mobility Unit (EMU) electronics equipment and Extravehicular Activity (EVA) astronaut are identified for various Space Station transmitters.

  8. Data collecting activities of the 'Outlook for Space' Panel. [information sources for technological forecasting survey

    NASA Technical Reports Server (NTRS)

    Stroud, W. G.

    1977-01-01

    The paper describes the work of the 'Outlook for Space' Panel, a NASA-wide study group concerned with the role space flight might play in American society during the years approaching 2000. The study considers the progression of projects from 'could do' (for which capability exists), to 'should do' (because of social benefits), to 'will do' (unknown at this time). Opinions as to objectives were solicited from NASA personnel, advisory committees, industrial organizations, and academic theoreticians. Poll data was examined. A large-scale survey of the attitudes of young people toward the future and space was also undertaken, and a complete matrix is presented of themes (such as production and management of food and forestry resources) and theme subcategory specific activities (for example, global crop production), versus the students' perceived areas of national interest or benefit (e.g., expansion of human knowledge).

  9. Space-based laser active imaging simulation system based on HLA

    NASA Astrophysics Data System (ADS)

    Han, Yi; Sun, Huayan; Li, Yingchun

    2013-09-01

    This paper adopts the High Level Architecture to develop the space-based laser active imaging distribution simulation software system, and designs the system framework which contains three-step workflow including modeling, experimental and analysis. The paper puts forward the general needs of the simulation system first, then builds the simulation system architecture based on HLA and constructs 7 simulation federal members. The simulation system has the primary functions of space target scattering characteristic analysis, imaging simulation, image processing and target recognition, and system performance analysis and so on, and can support the whole simulation process. The results show that the distribution simulation system can meet the technical requirements of the space-based laser imaging simulation.

  10. RS-34 Phoenix In-Space Propulsion System Applied to Active Debris Removal Mission

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Burnside, Christopher G.

    2014-01-01

    In-space propulsion is a high percentage of the cost when considering Active Debris Removal mission. For this reason it is desired to research if existing designs with slight modification would meet mission requirements to aid in reducing cost of the overall mission. Such a system capable of rendezvous, close proximity operations, and de-orbit of Envisat class resident space objects has been identified in the existing RS-34 Phoenix. RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. The National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC) gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC has obtained permission from the USAF to obtain all the remaining RS-34 stages for re-use opportunities. The MSFC Advanced Concepts Office (ACO) was commissioned to lead a study for evaluation of the Rocketdyne produced RS-34 propulsion system as it applies to an active debris removal design reference mission for resident space object targets including Envisat. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy payloads at multiple orbital locations. The RS-34 Concept Study lead by sought to further understand application for a similar orbital debris design reference mission to provide propulsive capability for rendezvous, close proximity operations to support the capture phase of the mission, and deorbit of single or multiple large class resident space objects. Multiple configurations varying the degree of modification were identified to trade for dry mass optimization and

  11. SCF E3 ligase PP2-B11 plays a positive role in response to salt stress in Arabidopsis

    PubMed Central

    Jia, Fengjuan; Wang, Chunyan; Huang, Jinguang; Yang, Guodong; Wu, Changai; Zheng, Chengchao

    2015-01-01

    Skp1–Cullin–F-box (SCF) E3 ligases are essential to the post-translational regulation of many important factors involved in cellular signal transduction. In this study, we identified an F-box protein from Arabidopsis thaliana, AtPP2-B11, which was remarkably induced with increased duration of salt treatment in terms of both transcript and protein levels. Transgenic Arabidopsis plants overexpressing AtPP2-B11 exhibited obvious tolerance to high salinity, whereas the RNA interference line was more sensitive to salt stress than wild-type plants. Isobaric tag for relative and absolute quantification analysis revealed that 4311 differentially expressed proteins were regulated by AtPP2-B11 under salt stress. AtPP2-B11 could upregulate the expression of annexin1 (AnnAt1) and function as a molecular link between salt stress and reactive oxygen species accumulation in Arabidopsis. Moreover, AtPP2-B11 influenced the expression of Na+ homeostasis genes under salt stress, and the AtPP2-B11 overexpressing lines exhibited lower Na+ accumulation. These results suggest that AtPP2-B11 functions as a positive regulator in response to salt stress in Arabidopsis. PMID:26041321

  12. Proteomic identification of potential target proteins regulated by the SCF(F) (bp1) -mediated proteolysis pathway in Fusarium oxysporum.

    PubMed

    Miguel-Rojas, Cristina; Hera, Concepcion

    2013-12-01

    F-box proteins function in the recruitment of proteins for SCF ubiquitination and proteasome degradation. Here, we studied the role of Fbp1, a nonessential F-box protein of the tomato pathogen Fusarium oxysporum f. sp. lycopersici. The Δfbp1 mutant showed a significant delay in the production of wilt symptoms on tomato plants and was impaired in invasive growth on cellophane membranes and on living plant tissue. To search for target proteins recruited by Fbp1, a combination of sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) was used to compare proteins in mycelia of the wild-type and Δfbp1 mutant. The proteomic approach identified 41 proteins differing significantly in abundance between the two strains, 17 of which were more abundant in the Δfbp1 mutant, suggesting a possible regulation by proteasome degradation. Interestingly, several of the identified proteins were related to vesicle trafficking. Microscopic analysis revealed an impairment of the Δfbp1 strain in directional growth and in the structure of the Spitzenkörper, suggesting a role of Fbp1 in hyphal orientation. Our results indicate that Fbp1 regulates protein turnover and pathogenicity in F. oxysporum. PMID:23855991

  13. Improved electronic properties from third-order SCC-DFTB with cost efficient post-SCF extensions.

    PubMed

    Kaminski, Steve; Gaus, Michael; Elstner, Marcus

    2012-12-01

    The present work outlines the implementation and performance of two cost efficient post-SCF extensions into the third-order SCC-DFTB code. The first one, the charge model 3 (CM3), corrects for errors in bond dipoles for an improved description of molecular charge distribution as compared to the standard Mulliken partitioning scheme. The second one focuses on the response of the charge density, that is, the electronic molecular polarizability, described inaccurately from SCC-DFTB due to the usage of a minimal atomic orbital basis. Here, a variational approach, based on scaled dipole integrals, was implemented, which clearly outperforms standard finite electric field approaches for polarizability calculations by approximately 1 order of magnitude. Both extensions in the present work rely on a set of empirical parameters, which were fitted against 112 organic molecules to match a reference data set from full density functional calculations with a large basis. As an achievement, notably improved electronic properties, that is, molecular dipole moments and polarizabilities, result from SCC-DFTB calculations at negligible additional computational cost. Furthermore, the accuracy of infrared and Raman intensities was tested as first-order derivatives of the new dipoles and polarizabilities as a function of normal mode vibrations. As a result, the current implementations cannot contribute to an improved prediction of relative intensity pattern from SCC-DFTB as compared to ab initio reference data. PMID:23167841

  14. Differential amygdala activation during simulated personal space intrusion by men and women.

    PubMed

    Wabnegger, Albert; Leutgeb, Verena; Schienle, Anne

    2016-08-25

    Responses to personal space (PS) violations are variable and depend (besides many other factors) on the sex of the person who enters this space. The neuronal basis of this effect is still largely unknown. A previous neuroimaging investigation had shown that male participants responded with increased amygdala activation to PS violation, but only when the intruder was male. Gender-specific responses by females have not been studied yet. In the present study we recorded affective as well as hemodynamic responses of 30 women (mean age: M=27.3years; SD=8.1). The participants were exposed to images of neutral facial expressions from men and women. All stimuli were once shown as photos (static), and once were zoomed in (picture enlargement by the factor 2.75) in order to simulate PS intrusion. In both conditions ('static' and 'approaching' faces) the eyes and mouth region of the depicted persons were always completely visible. Approaching faces generally provoked activation of a parietal network (e.g., intraparietal sulcus, superior/inferior parietal cortex). When the approaching person was male additional amygdala activation was detected. Because the amygdala is a central structure for the initiation of defense responses, the heightened activation might reflect that male intrusion was decoded as potential threat. Hence, we observed a similar gender bias to simulated space intrusion in women as previously in men. PMID:27246442

  15. Managing urine leakage following laparoscopic radical prostatectomy with active suction of the prevesical space

    PubMed Central

    Stránský, Petr; Klečka, Jiří; Trávníček, Ivan; Ürge, Tomáš; Eret, Viktor; Ferda, Jiří; Petersson, Fredrik; Hes, Ondřej

    2012-01-01

    Introduction Urine leakage following laparoscopic radical prostatectomy (LRP) is a possible complication that may herald chronic urine incontinence. Intraoperative measures aiming to prevent this is not standardised. Aim Presentation of experience with active suction of the prevesical space in managing postoperative urine leakage. Material and methods At the Department of Urology, where laparoscopy of the upper abdomen and open RP were performed, a protocol for extraperitoneal LRP was established in 8/2008. Until 5/2011, 154 LRPs have been performed. Urine leakage from a suction drain appeared in 9 cases (5.8%). Permanent active suction (with a machine for Büllae thoracic drainage) of the prevesical space with negative pressure of 7-12 cm of H2O was started immediately. Results Urine leakage started after a mean of 0.9 (0-2) days postoperatively and stopped after a mean of 8.1 (15-42) days. Leakage stopped with only suctioning in 7 cases. In one case, open re-anastomosis was performed on the 7th postoperative day (POD). In another case, ineffective active suction was replaced on the 10th POD by needle vented suction without effect and the leakage stopped following gradual shortening of the drain up to the 15th POD. Conclusions Active suction of the prevesical space seems to be an effective intervention to stop postoperative urine leakage after laparoscopic radical prostatectomy. PMID:23630554

  16. Living Together in Space: The International Space Station Internal Active Thermal Control System Issues and Solutions-Sustaining Engineering Activities at the Marshall Space Flight Center From 1998 to 2005

    NASA Technical Reports Server (NTRS)

    Wieland, P. O.; Roman, M. C.; Miller, L.

    2007-01-01

    On board the International Space Station, heat generated by the crew and equipment is removed by the internal active thermal control system to maintain a comfortable working environment and prevent equipment overheating. Test facilities simulating the internal active thermal control system (IATCS) were constructed at the Marshall Space Flight Center as part of the sustaining engineering activities to address concerns related to operational issues, equipment capability, and reliability. A full-scale functional simulator of the Destiny lab module IATCS was constructed and activated prior to launch of Destiny in 2001. This facility simulates the flow and thermal characteristics of the flight system and has a similar control interface. A subscale simulator was built, and activated in 2000, with special attention to materials and proportions of wetted surfaces to address issues related to changes in fluid chemistry, material corrosion, and microbial activity. The flight issues that have arisen and the tests performed using the simulator facilities are discussed in detail. In addition, other test facilities at the MSFC have been used to perform specific tests related to IATCS issues. Future testing is discussed as well as potential modifications to the simulators to enhance their utility.

  17. Nonplanar structure of C6H5SCF3 facilitates πσ∗-mediated photodissociation reaction on the S1 state

    NASA Astrophysics Data System (ADS)

    Kim, So-Yeon; Lee, Jeongmook; Kim, Sang Kyu; Choi, Young S.

    2016-08-01

    Vibrational structure of trifluoromethylthiobenzene (C6H5SCF3) on the S1 state has been investigated by resonance-enhanced two-photon ionization spectroscopy and nature of predissociation dynamics is inferred from homogeneously broadened spectral features. As C6H5SCF3 adopts a nonplanar structure in both the S0 and S1 states, the effective adiabatic barrier generated by avoided crossing of optically-bright bound S1 (ππ∗) and dark-repulsive S2 (πσ∗) surfaces along the reaction coordinate is significantly lowered, giving the S1 lifetime of ∼300 fs. This experiment demonstrates that the molecular structure spanned by the reactive flux near the curve-crossing region dictates reaction rate as well as nonadiabatic transition probability.

  18. [Effect of space flight on the Kosmos-1129 biosatellite on enzyme activity of the rat liver].

    PubMed

    Nemeth, S; Tigranian, R A

    1983-01-01

    After the 18.5 day Cosmos-1129 flight the activity of 7 glucocorticoid-stimulated enzymes of the rat liver was measured. Immediately postflight the activity of tyrosine aminotransferase, tryptophan pyrolase and serine dehydrogenase increased. These enzymes rapidly (within several hours) react to increased glucocorticoids. The activity of aspartate and alanine aminotransferases also increased. These enzymes require many days of a continuous effect of glucocorticoids. The glycogen concentration in the rat liver also grew. At R + 6 the activity of tryptophan pyrolase and serine dehydrogenase decreased and that of the other enzymes returned to normal. The immobilization stress applied postflight led to an increased activity of tyrosine aminotransferase and tryptophan pyrolase. This study gives evidence that after space flight rats are in an acute stress state, evidently, produced by the biosatellite recovery. PMID:6620954

  19. Multi-Agent System for Managing Human Activities in Space Operations

    NASA Technical Reports Server (NTRS)

    Schrenkenghost, Debra; Bonasso, R. Peter

    2006-01-01

    In manned space operations today, the astronauts' activity schedules are preplanned and adjusted daily on Earth. We have developed the Distributed Collaboration and Interaction (DCI) multi-agent system to investigate automating aspects of human activity management. The DCI System assists (1) plan generation, (2) human activity tracking, (3) plan revision, and (4) mixed initiative interaction with the plan. We have deployed and evaluated the DCI system at JSC to assist control engineers in managing anomaly handling activities for automated life support systems. DCI operated round the clock for 20 months in the Water Research Facility at JSC. Using this software, we reduced anomaly response time by engineers from up to 10 hours in previous tests to under an hour. Based on this evaluation, we conclude that agent assistance for schedule management has potential to improve astronaut activity awareness and reduce response time in situations where crew are interrupted to handle anomalies.

  20. Active learning in the space engineering education at Technical University of Madrid

    NASA Astrophysics Data System (ADS)

    Rodríguez, Jacobo; Laverón-Simavilla, Ana; Lapuerta, Victoria; Ezquerro Navarro, Jose Miguel; Cordero-Gracia, Marta

    This work describes the innovative activities performed in the field of space education at the Technical University of Madrid (UPM), in collaboration with the center engaged by the European Space Agency (ESA) in Spain to support the operations for scientific experiments on board the International Space Station (E-USOC). These activities have been integrated along the last academic year of the Aerospatiale Engineering degree. A laboratory has been created, where the students have to validate and integrate the subsystems of a microsatellite by using demonstrator satellites. With the acquired skills, the students participate in a training process centered on Project Based Learning, where the students work in groups to perform the conceptual design of a space mission, being each student responsible for the design of a subsystem of the satellite and another one responsible of the mission design. In parallel, the students perform a training using a ground station, installed at the E-USOC building, which allow them to learn how to communicate with satellites, how to download telemetry and how to process the data. This also allows students to learn how the E-USOC works. Two surveys have been conducted to evaluate the impact of these techniques in the student engineering skills and to know the degree of satisfaction of students with respect to the use of these learning methodologies.

  1. An electronic structure study of acetone by electron momentum spectroscopy: a comparison with SCF, MRSD-CI and density functional theory

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Neville, J. J.; Brion, C. E.; Wang, Y.; Davidson, E. R.

    1994-11-01

    The binding energy spectra and momentum distributions of all valence orbitals of acetone have been studied by electron momentum spectroscopy (EMS) and SCF, MRSD-CI, and density functional theory (DFT) calculations. The experiment was performed using a multichannel EMS spectrometer at a total energy of 1200 eV. Binding energy spectra measured in the energy range of 6-60 eV are compared with the results of OVGF and 2ph-TDA many-body Green's function calculations. In the inner valence region strong splitting of the 5a 1 and 4a 1 orbitals due to final state electron correlation is observed. The distribution of energies and pole strengths predicted by the Green's function calculations deviates considerably from the measured ionization energies and strengths in the innervalence region. The measured momentum distributions are compared with calculations at the level of the target Hartree-Fock approximation (THFA) using the SCF method and the target Kohn-Sham approximation (TKSA) using DFT and the local-density approximation. Basis sets used for the SCF calculations ranged from the simplest (STO-3G) to large (204-GTO) and for the DFT calculations very large atomic natural orbital (ANO) basis sets were used. The effects of electron correlation and relaxation are also investigated in MRSD-CI calculations of the full ion-neutral overlap amplitude using large and saturated basis sets. In general, the THFA model with an intermediate basis set and very diffuse functions (6-311 + +G ∗∗) and with a near Hartree-Fock limit SCF wavefunction (204-GTO), and the TKSA-DFT model with an ANO basis set all provide reasonable predictions of momentum distributions for most orbitals. However, none of these calculations gives a completely satisfactory description of the momentum distribution of the HOMO (5b 2) orbital.

  2. Protein Kinase R Degradation Is Essential for Rift Valley Fever Virus Infection and Is Regulated by SKP1-CUL1-F-box (SCF)FBXW11-NSs E3 Ligase

    PubMed Central

    Mudhasani, Rajini; Tran, Julie P.; Retterer, Cary; Kota, Krishna P.; Whitehouse, Chris A.; Bavari, Sina

    2016-01-01

    Activated protein kinase R (PKR) plays a vital role in antiviral defense primarily by inhibiting protein synthesis and augmenting interferon responses. Many viral proteins have adopted unique strategies to counteract the deleterious effects of PKR. The NSs (Non-structural s) protein which is encoded by Rift Valley fever virus (RVFV) promotes early PKR proteasomal degradation through a previously undefined mechanism. In this study, we demonstrate that NSs carries out this activity by assembling the SCF (SKP1-CUL1-F-box)FBXW11 E3 ligase. NSs binds to the F-box protein, FBXW11, via the six amino acid sequence DDGFVE called the degron sequence and recruits PKR through an alternate binding site to the SCFFBXW11 E3 ligase. We further show that disrupting the assembly of the SCFFBXW11-NSs E3 ligase with MLN4924 (a small molecule inhibitor of SCF E3 ligase activity) or NSs degron viral mutants or siRNA knockdown of FBXW11 can block PKR degradation. Surprisingly, under these conditions when PKR degradation was blocked, NSs was essential and sufficient to activate PKR causing potent inhibition of RVFV infection by suppressing viral protein synthesis. These antiviral effects were antagonized by the loss of PKR expression or with a NSs deleted mutant virus. Therefore, early PKR activation by disassembly of SCFFBXW11-NSs E3 ligase is sufficient to inhibit RVFV infection. Furthermore, FBXW11 and BTRC are the two homologues of the βTrCP (Beta-transducin repeat containing protein) gene that were previously described to be functionally redundant. However, in RVFV infection, among the two homologues of βTrCP, FBXW11 plays a dominant role in PKR degradation and is the limiting factor in the assembly of the SCFFBXW11 complex. Thus, FBXW11 serves as a master regulator of RVFV infection by promoting PKR degradation. Overall these findings provide new insights into NSs regulation of PKR activity and offer potential opportunities for therapeutic intervention of RVFV infection. PMID

  3. Modified independent modal space control method for active control of flexible systems

    NASA Technical Reports Server (NTRS)

    Baz, A.; Poh, S.

    1987-01-01

    A modified independent modal space control (MIMSC) method is developed for designing active vibration control systems for large flexible structures. The method accounts for the interaction between the controlled and residual modes. It incorporates also optimal placement procedures for selecting the optimal locations of the actuators in the structure in order to minimize the structural vibrations as well as the actuation energy. The MIMSC method relies on an important feature which is based on time sharing of a small number of actuators, in the modal space, to control effectively a large number of modes. Numerical examples are presented to illustrate the application of the method to generic flexible systems. The results obtained suggest the potential of the devised method in designing efficient active control systems for large flexible structures.

  4. Cloud and radiation mission with active and passive sensing from the space station

    SciTech Connect

    Spinhirne, James D.

    1999-01-22

    A cloud and aerosol radiative forcing and physical process study involving active laser and radar profiling with a combination of passive radiometric sounders and imagers would use the space station as an observation platform. The objectives are to observe the full three dimensional cloud and aerosol structure and the associated physical parameters leading to a complete measurement of radiation forcing processes. The instruments would include specialized radar and lidar for cloud and aerosol profiling, visible, infrared and microwave imaging radiometers with comprehensive channels for cloud and aerosol observation and specialized sounders. The low altitude, available power and servicing capability of the space station are significant advantages for the active sensors and multiple passive instruments.

  5. Summary of Current and Future MSFC International Space Station Environmental Control and Life Support System Activities

    NASA Technical Reports Server (NTRS)

    Ray, Charles D.; Carrasquillo, Robyn L.; Minton-Summers, Silvia

    1997-01-01

    This paper provides a summary of current work accomplished under technical task agreement (TTA) by the Marshall Space Flight Center (MSFC) regarding the Environmental Control and Life Support System (ECLSS) as well as future planning activities in support of the International Space Station (ISS). Current activities include ECLSS computer model development, component design and development, subsystem integrated system testing, life testing, and government furnished equipment delivered to the ISS program. A long range plan for the MSFC ECLSS test facility is described whereby the current facility would be upgraded to support integrated station ECLSS operations. ECLSS technology development efforts proposed to be performed under the Advanced Engineering Technology Development (AETD) program are also discussed.

  6. In-situ resource utilization activities at the NASA Space Engineering Research Center

    NASA Technical Reports Server (NTRS)

    Ramohalli, Kumar

    1992-01-01

    The paper describes theoretical and experimental research activities at the NASA Space Engineering Research Center aimed at realizing significant cost savings in space missions through the use of locally available resources. The fundamental strategy involves idea generation, scientific screening, feasibility demonstrations, small-scale process plant design, extensive testing, scale-up to realistic production rates, associated controls, and 'packaging', while maintaining sufficient flexibility to respond to national needs in terms of specific applications. Aside from training, the principal activities at the Center include development of a quantitative figure-of-merit to quickly assess the overall mission impact of individual components that constantly change with advancing technologies, extensive tests on a single-cell test bed to produce oxygen from carbon dioxide, and the use of this spent stream to produce methane.

  7. TECHBREAK: a technology foresight activity for the European Space Agency points the way to future space telescopes

    NASA Astrophysics Data System (ADS)

    Cunningham, Colin; Cullum, Martin; Detsis, Emmanouil; Henry, David; Kamoun, Paul; Swings, Jean-Pierre; Tortora, Jean-Jacques; Worms, Jean-Claude

    2015-09-01

    We report on a joint European Science Foundation-ESA "Forward Look" project called TECHBREAK aimed at identifying technological breakthroughs for space originating in the non-space sector. We show how some of the technologies highlighted may impact future space programmes, in particular novel ideas to enable future long-life large telescopes to be deployed. The study's final report was presented to ESA's High level Science Policy Advisory Committee (HISPAC) in late 2014. The goals of the study were to forecast the development of breakthrough technologies to enable novel space missions in the 2030-2050 timeframe, and to identify related partnerships through synergies with non-space specialists. It was not prepared to serve as a definitive guide for very specific technologies to be developed for future space missions, but to inform on and flag up the main developments in various technological and scientific areas outside space that may hold promise for use in the space domain. The report does this by identifying the current status of research for each domain, asserting the development horizon for each technology and providing some entry points, in the form of key European experts and institutions with knowledge of the domain. The identification of problems and solutions specific to the space area led us to focus the discussion around the concept of "Overwhelming Drivers" for space research and exploration, i.e. long-term goals that can be transposed into technological development goals. Two of these overwhelming drivers are directly relevant to ambitious future telescope projects, and we will show how some of the technologies we identified such as biomimetic structures, nanophotonics, novel materials and additive manufacturing could be combined to enable revolutionary new concepts for space telescopes.

  8. Structural basis of the Cks1-dependent recognition of p27(Kip1) by the SCF(Skp2) ubiquitin ligase

    SciTech Connect

    Hao, B.; Zheng, N.; Schulman, B.A.; Wu, G.; Miller, J.J.; Pagano, M.; Pavletich, N.P.

    2010-07-19

    The ubiquitin-mediated proteolysis of the Cdk2 inhibitor p27{sup Kip1} plays a central role in cell cycle progression, and enhanced degradation of p27{sup Kip1} is associated with many common cancers. Proteolysis of p27{sup Kip1} is triggered by Thr187 phosphorylation, which leads to the binding of the SCF{sup Skp2} (Skp1-Cul1-Rbx1-Skp2) ubiquitin ligase complex. Unlike other known SCF substrates, p27{sup Kip1} ubiquitination also requires the accessory protein Cks1. The crystal structure of the Skp1-Skp2-Cks1 complex bound to a p27{sup Kip1} phosphopeptide shows that Cks1 binds to the leucine-rich repeat (LRR) domain and C-terminal tail of Skp2, whereas p27{sup Kip1} binds to both Cks1 and Skp2. The phosphorylated Thr187 side chain of p27{sup Kip1} is recognized by a Cks1 phosphate binding site, whereas the side chain of an invariant Glu185 inserts into the interface between Skp2 and Cks1, interacting with both. The structure and biochemical data support the proposed model that Cdk2-cyclin A contributes to the recruitment of p27{sup Kip1} to the SCF{sup Skp2}-Cks1 complex.

  9. Activity of the sympathoadrenal system in cosmonauts during 25-day space flight on station Mir

    NASA Astrophysics Data System (ADS)

    Kvetňanský, R.; Noskov, V. B.; Blazicek, P.; Gharib, C.; Popova, I. A.; Gauquelin, G.; Macho, L.; Guell, A.; Grigoriev, A. I.

    The activity of the sympathoadrenal system in cosmonauts was studied by measuring plasma and urinary catecholamines and their metabolites and conjugates. The appliance Plasma 02 was used for collecting, processing, and storing blood and urine samples from the cosmonauts during the course of a 25-day flight on board the station Mir. Plasma and urine concentrations of adrenaline (A), noradrenaline (NA), and dopamine (DA) as well as urinary levels of vanillylmandelic acid (VMA) and homovanillic acid (HVA), and plasma levels of catecholamine sulphates were determined before, during and after the space flight. Plasma NA levels were slightly elevated on day 9 and plasma A on day 20, whereas plasma DA levels were unchanged. However, most of the changes were within the normal range of control values. Sulphates of plasma catecholamines did not change during flight but they were significantly elevated after landing. Urinary levels of A, NA, DA, VMA, and HVA were comparable with preflight values but were elevated at the different intervals studied after landing. The results obtained suggest that in the short period of about 9 days of the cosmonaut's stay in space the sympathoadrenal system was slightly activated indicating a mild stressful influence of the initial period of flight. This short-term space flight compared to long-term flight did not as markedly activate the sympathoadrenal system during the process of re-adaptation to Earth's gravity after landing. Our data suggest that weightlessness is not a stressful factor activating the sympathoadrenal system but it sensitizes the responsiveness of this system during the re-adaptation period after space flight.

  10. The role of EVA on Space Shuttle. [experimental support and maintenance activities

    NASA Technical Reports Server (NTRS)

    Carson, M. A.

    1974-01-01

    The purpose of this paper is to present the history of Extravehicular Activity (EVA) through the Skylab Program and to outline the expected tasks and equipment capabilities projected for the Space Shuttle Program. Advantages offered by EVA as a tool to extend payload capabilities and effectiveness and economic advantages of using EVA will be explored. The presentation will conclude with some guidelines and recommendations for consideration by payload investigators in establishing concepts and designs utilizing EVA support.

  11. Forecasting the Solar Drivers of Severe Space Weather from Active-Region Magnetograms

    NASA Technical Reports Server (NTRS)

    Falconer, David A.; Moore, Ronald L.; Barghouty, Abdulnasser F.; Khazanov, Igor

    2012-01-01

    Solar drivers of severe space weather can be predicted from line-of-sight magnetograms, via a free-energy proxy measured from the neutral lines. This can be done in near real time. In addition to depending strongly on the free magnetic energy, an active region's chance of having a major eruption depends strongly on other aspects of the evolving magnetic field (e.g., its complexity and flux emergence).

  12. Doppler and range determination for deep space vehicles using active optical transponders

    NASA Technical Reports Server (NTRS)

    Kinman, Peter W.; Gagliardi, Robert M.

    1988-01-01

    This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated.

  13. Phosphorylation and SCF-mediated degradation regulate CREB-H transcription of metabolic targets

    PubMed Central

    Barbosa, Sónia; Carreira, Suzanne; Bailey, Daniel; Abaitua, Fernando; O'Hare, Peter

    2015-01-01

    CREB‑H, an endoplasmic reticulum–anchored transcription factor, plays a key role in regulating secretion and in metabolic and inflammatory pathways, but how its activity is modulated remains unclear. We examined processing of the nuclear active form and identified a motif around S87–S90 with homology to DSG-type phosphodegrons. We show that this region is subject to multiple phosphorylations, which regulate CREB-H stability by targeting it to the SCFFbw1a E3 ubiquitin ligase. Data from phosphatase treatment, use of phosophospecific antibody, and substitution of serine residues demonstrate phosphorylation of candidate serines in the region, with the core S87/S90 motif representing a critical determinant promoting proteasome-mediated degradation. Candidate kinases CKII and GSK-3b phosphorylate CREB-H in vitro with specificities for different serines. Prior phosphorylation with GSK-3 at one or more of the adjacent serines substantially increases S87/S90-dependent phosphorylation by CKII. In vivo expression of a dominant-negative Cul1 enhances steady-state levels of CREB‑H, an effect augmented by Fbw1a. CREB-H directly interacts with Fbw1a in a phosphorylation-dependent manner. Finally, mutations within the phosphodegron, when incorporated into the full-length protein, result in increased levels of constitutively cleaved nuclear protein and increased transcription and secretion of a key endogenous target gene, apolipoprotein A IV. PMID:26108621

  14. Space charge effects on the active region of a planar organic photodetector

    NASA Astrophysics Data System (ADS)

    Agostinelli, T.; Caironi, M.; Natali, D.; Sampietro, M.; Biagioni, P.; Finazzi, M.; Duò, L.

    2007-06-01

    Planar organic photodetectors represent a simple, cheap, and versatile alternative to devices built in sandwich configuration. The nonuniform electric field distribution in these structures has significant consequences on the extent of the device active region, because photogeneration of free carriers in organic semiconductors is a field-assisted phenomenon. By means of microscopy mapping of the photocurrent in a poly(p-phenylene vinylene) based planar device, we show that due to the deep trapping of photogenerated electrons leading to negative space charge accumulation, exciton dissociation occurs only close to the positively biased electrode. The effect of large leakage currents in defining the device active region is also analyzed and discussed.

  15. Modelling the evolution of Comet Siding Spring's activity using Herschel Space Observatory measurements

    NASA Astrophysics Data System (ADS)

    Kiss, Csaba; Müller, Thomas; Kidger, Mark Richard; Mattisson, Peter; Marton, Gabor

    2015-08-01

    Comet Siding Spring was observed with the Herschel Space Observatory in March 2013 at a heliocentric distance of 6.5 au, already showing siginficant activity. Using the far-infrared radial intensity profiles of the coma at 70, 100 and 160um we were able to construct a detailed model of the dust emission and costrain the dust properties. Our results show a significant overaboundance of large grains in the coma with a size frequency index of ~2. We were also able to estimate the activity onset time: this likely happened at a helicentric distance of ~8 au, six months before the Herschel observations.

  16. The Role of Human Intelligence in the USAs 1960s Efforts to Understand Soviet Space Activities

    NASA Astrophysics Data System (ADS)

    Pesavento, P.

    Recent declassification of material from the Interagency Security Classification Appeals Panel (ISCAP) and the archives of the US State Department provide several new insights into US intelligence's knowledge of Soviet Space Activities and sources of that knowledge. It is apparent that there was a significant human intelligence source providing information on subjects such as the USSR's Voskhod 3 mission and manned lunar program activities. This new understanding shows that US intelligence was employing the complete panoply of intelligence tools and that human intelligence appears to have provided many key understandings

  17. Introduction to Radiation Issues for International Space Station Extravehicular Activities. Chapter 1

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Saganti, P. B.; Miller, J.; Cucinotta, F. A.

    2003-01-01

    The International Space Station (ISS) provides significant challenges for radiation protection of the crew due to a combination of circumstances including: the extended duration of missions for many crewmembers, the exceptionally dynamic nature of the radiation environment in ISS orbit, and the necessity for numerous planned extravehicular activities (EVA) for station construction and maintenance. Radiation protection requires accurate radiation dose measurements and precise risk modeling of the transmission of high fluxes of energetic electrons and protons through the relatively thin shielding provided by the space suits worn during EVA. Experiments and analyses have been performed due to the necessity to assure complete radiation safety for the EVA crew and thereby ensure mission success. The detailed characterization described of the material and topological properties of the ISS space suits can be used as a basis for design of space suits used in future exploration missions. In radiation protection practices, risk from exposure to ionizing radiation is determined analytically by the level of exposure, the detrimental quality of the radiation field, the inherent radiosensitivity of the tissues or organs irradiated, and the age and gender of the person at the time of exposure. During low Earth orbit (LEO) EVA, the relatively high fluxes of low-energy electrons and protons lead to large variations in exposure of the skin, lens of the eye, and tissues in other shallow anatomical locations. The technical papers in this publication describe a number of ground-based experiments that precisely measure the thickness of the NASA extravehicular mobility unit (EMU) and Russian Zvezda Orlan-M suits using medical computerized tomography (CT) X-ray analysis, and particle accelerator experiments that measure the minimum kinetic energy required by electrons and photons to penetrate major components of the suits. These studies provide information necessary for improving the

  18. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    SciTech Connect

    Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

    2014-10-10

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  19. Anti-hierarchical Evolution of the Active Galactic Nucleus Space Density in a Hierarchical Universe

    NASA Astrophysics Data System (ADS)

    Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

    2014-10-01

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  20. MERLIN : a Franco-German active space mission dedicated to atmospheric methane

    NASA Astrophysics Data System (ADS)

    Bousquet, P.; Marshall, J.; Pierangelo, C.; Ehret, G.; Bacour, C.; Chevallier, F.; Gibert, F.; Crevoisier, C. D.; Edouart, D.; Esteve, F.; Chinaud, J.; Armante, R.; Berthier, S.; Alpers, M.; Millet, B.

    2015-12-01

    The Methane Remote Sensing Lidar Mission (MERLIN), currently in phase B, is a joint cooperation between France and Germany on the development, launch and operation of a space LIDAR dedicated to the retrieval of total methane (CH4) atmospheric columns. Atmospheric methane is the second most anthropogenic gas, contributing 20% to climate radiative forcing but also plying an important role in atmospheric chemistry as a precursor of tropospheric ozone and low-stratosphere water vapour. For the first time, measurements of atmospheric composition will be performed from space thanks to an IPDA (Integrated Path Differential Absorption) LIDAR (Light Detecting And Ranging), with a precision (target 20 ppb for a 50km aggregation along the trace) and accuracy (target 3 ppb) sufficient to improve the constraints on methane fluxes compared to current observation networks. The very low systematic error target is ambitious compared to current methane space mission, but achievable because of the differential active measurements of MERLIN, which guarantees almost no contamination by aerosols or water vapour cross-sensitivity. As an active mission, MERLIN will deliver data for all seasons and all altitudes, day and night. Here, we present the MERLIN mission and its objectives in terms of reduction of uncertainties on methane surface emissions. To do so, we propose an OSSE analysis (observing system simulation experiment) to estimate the uncertainty reduction brought by MERLIN. The originality of our system is to transfer both random and systematic errors from the observation space to the flux space, thus providing more realistic error reductions than currently provided in OSSE only using the random part of errors. To do so, a precise analysis of causes of errors has been done for the MERLIN mission and is also presented.

  1. MERLIN : a Franco-German active space mission dedicated to atmospheric methane

    NASA Astrophysics Data System (ADS)

    Bousquet, Philippe; Gibert, Fabien; Marshall, Julia; Pierangelo, Clémence; Ehret, Gerhard; Bacour, Cédric; Chevallier, Frédéric; Crevoisier, Cyril; Edouart, Dimitri; Esteve, Frédéric; Chinaud, Jordi; Armante, Raymond; Kiemle, Christoph; Alpers, Matthias; Tinto, Fransesc; Millet, Bruno

    2016-04-01

    The Methane Remote Sensing Lidar Mission (MERLIN), currently in phase B, is a joint cooperation between France and Germany on the development, launch and operation of a space LIDAR dedicated to the retrieval of total methane (CH4) atmospheric columns. Atmospheric methane is the second most anthropogenic gas, contributing 20% to climate radiative forcing but also plying an important role in atmospheric chemistry as a precursor of tropospheric ozone and low-stratosphere water vapour. For the first time, measurements of atmospheric composition will be performed from space thanks to an IPDA (Integrated Path Differential Absorption) LIDAR (Light Detecting And Ranging), with a precision (target 20 ppb for a 50km aggregation along the trace) and accuracy (target 3 ppb) sufficient to improve the constraints on methane fluxes compared to current observation networks. The very low systematic error target is ambitious compared to current methane space mission, but achievable because of the differential active measurements of MERLIN, which guarantees almost no contamination by aerosols or water vapour cross-sensitivity. As an active mission, MERLIN will deliver data for all seasons and all altitudes, day and night. Here, we present the MERLIN mission and its objectives in terms of reduction of uncertainties on methane surface emissions. To do so, we propose an OSSE analysis (observing system simulation experiment) to estimate the uncertainty reduction brought by MERLIN. An analysis of causes of errors has been done for the MERLIN mission and is presented. The originality of our system is to transfer both random and systematic errors from the observation space to the flux space, thus providing more realistic error reductions than currently provided in OSSE only using the random part of errors. Error reductions are presented using two different atmospheric transport models, TM3 and LMDZ, and compared with error reductions achieved with the GOSAT passive mission.

  2. Moving Beyond Neighborhood: Activity Spaces and Ecological Networks As Contexts for Youth Development.

    PubMed

    Browning, Christopher R; Soller, Brian

    2014-01-01

    Many scholars, policy analysts, and practitioners agree that neighborhoods are important contexts for urban youth. Yet, despite decades of research, our knowledge of why and how neighborhoods influence the day-to-day lives of youth is still emerging. Theories about neighborhood effects largely assume that neighborhoods operate to influence youth through exposure-based mechanisms. Extant theoretical approaches, however, have neglected the processes by which neighborhood socioeconomic contexts influence the routine spatial exposures-or activity spaces-of urban residents. In this article, we argue that exposure to organizations, institutions, and other settings that characterize individual activity spaces is a key mechanism through which neighborhoods influence youth outcomes. Moreover, we hypothesize that aggregate patterns of shared local exposure-captured by the concept of ecological networks-are influenced by neighborhood socioeconomic characteristics and are independently consequential for neighborhood youth. Neighborhoods in which residents intersect in space more extensively as a result of routine conventional activities will exhibit higher levels of social capital relevant to youth well-being, including (1) familiarity, (2) beneficial (weak) social ties, (3) trust, (4) shared expectations for pro-social youth behavior (collective efficacy), and (5) the capacity for consistent monitoring of public space. We then consider the implications of ecological networks for understanding the complexities of contextual exposure. We specifically discuss the role of embeddedness in ecological communities-that is, clusters of actors and locations that intersect at higher rates-for understanding contextual influences that are inadequately captured by geographically defined neighborhoods. We conclude with an overview of new approaches to data collection that incorporate insights from an activity-space and ecological-network perspective on neighborhood and contextual influences

  3. Cardiovascular and Cerebrovascular Control on Return from International Space Station (CCISS)- Heart Rate and Activity

    NASA Astrophysics Data System (ADS)

    Hughson, R. L.; Shoemaker, J. K.; Blaber, A. P.; Arbeille, Ph.; Zuj, K. A.; Greaves, D. K.

    2008-06-01

    CCISS is a project to study the cardiovascular and cerebrovascular responses of astronauts before, during and after long-duration (>60-day) stays on the International Space Station. The CCISS experiments consist of three phases that are designed to achieve an integrated examination of components responsible for return of blood to the heart, the pumping of blood from the heart and the distribution to the vascular territories including the brain. In this report the data are obtained from the 24-h monitoring of physical activity (Actiwatch on wrist and ankle) and of heart rate (Holter monitor). The data show clear patterns of change in physical activity from predominantly leg-based on Earth to relatively little activity of the ankles with maintained or increased activity of the wrists on ISS. Both on Earth and on ISS the largest changes in heart rate occur during the periods of leg activity. Average heart rate was changed little during the periods of minimal activity or of sleep in comparisons of Earth with in-flight recording both within the first two weeks of flight and the last two weeks. These data clearly show the importance of monitoring heart rate and physical activity simultaneously and show that attempts to derive indicators of autonomic activity from spectral analysis of heart rate variability should not be performed in the absence of knowledge of both variables.

  4. Technology Development Activities for the Space Environment and Its Effects On Spacecraft

    NASA Technical Reports Server (NTRS)

    Kauffman, Billy; Hardage, Donna; Minor, Jody; Pearson, Steven D. (Technical Monitor)

    2002-01-01

    Reducing size and weight of spacecraft, along with demanding increased performance capabilities, introduces many uncertainties in the engineering design community on how emerging microelectronics will perform in space. The engineering design community is forever behind on obtaining and developing new tools and guidelines to mitigate the harmful effects of the space environment. Adding to this complexity is the push to use Commercial-off-the-Shelf (COTS) and shrinking microelectronics behind less shielding and the potential usage of unproven technologies such as large solar sail structures and nuclear electric propulsion. In order to drive down these uncertainties, various programs are working together to avoid duplication, save what resources are available in this technical area and possess a focused agenda to insert these new developments into future mission designs. This paper will describe the relationship between the Living With a Star: Space Environment Testbeds Project and NASA's Space Environments and Effects (SEE) Program and their technology development activities funded as a result from the recent SEE Program's NASA Research Announcement.

  5. The support system of the firefighter's activity by detecting objects in smoke space

    NASA Astrophysics Data System (ADS)

    Sakai, Masaki; Aoki, Yoshimitsu; Takagi, Mikio

    2005-12-01

    In recent years, crisis management's response to terrorist attacks and natural disasters, as well as accelerating rescue operations has become an important issue. We aim to make a support system for firefighters using the application of various engineering techniques such as information technology and radar technology. In rescue operations, one of the biggest problems is that the view of firefighters is obstructed by dense smoke. One of the current measures against this condition is the use of search sticks, like a blind man walking in town. The most important task for firefighters is to understand inside situation of a space with dense smoke. Therefore, our system supports firefighters' activity by visualizing the space with dense smoke. First, we scan target space with dense smoke by using millimeter-wave radar combined with a gyro sensor. Then multiple directional scan data can be obtained, and we construct a 3D map from high-reflection point dataset using 3D image processing technologies (3D grouping and labeling processing). In this paper, we introduce our system and report the results of the experiment in the real smoke space situation and practical achievements.

  6. Technology Development Activities for the Space Environment and its Effects on Spacecraft

    NASA Technical Reports Server (NTRS)

    Kauffman, Billy; Hardage, Donna; Minor, Jody; Barth, Janet; LaBel, Ken

    2003-01-01

    Reducing size and weight of spacecraft, along with demanding increased performance capabilities, introduces many uncertainties in the engineering design community on how emerging microelectronics will perform in space. The engineering design community is forever behind on obtaining and developing new tools and guidelines to mitigate the harmful effects of the space environment. Adding to this complexity is the push to use Commercial-off-the-shelf (COTS) and shrinking microelectronics behind less shielding and the potential usage of unproven technologies such as large solar sail structures and nuclear electric propulsion. In order to drive down these uncertainties, various programs are working together to avoid duplication, save what resources are available in this technical area and possess a focused agenda to insert these new developments into future mission designs. This paper will describe the relationship between the Living With a Star (LWS): Space Environment Testbeds (SET) Project and NASA's Space Environments and Effects (SEE) Program and their technology development activities funded as a result from the recent SEE Program's NASA Research Announcement.

  7. Assembly of spaced chromatin involvement of ATP and DNA topoisomerase activity.

    PubMed Central

    Almouzni, G; Méchali, M

    1988-01-01

    Undiluted extracts from eggs or oocytes of Xenopus laevis support the assembly of chromatin with physiologically spaced nucleosomes. Micrococcal nuclease and DNase I digestion experiments show that nucleosome formation as well as supercoiling of circular DNA concomitant to assembly do not require ATP or Mg2+. However these factors are essential for the stability and the physiological spacing of the assembled chromatin. gamma-S-ATP can substitute for ATP in this process. With topoisomers of defined linking number topological interconversions proceed by steps of unity, both in vitro as well as in vivo, indicating that topoisomerase I is dominantly acting in this process. Novobiocin sensitivity occurred only with diluted extracts and was unrelated to an inhibition of topoisomerase II. Finally, nucleosome assembly occurs efficiently on linear DNA although the assembled DNA is less stable than with circular DNA. From these results we propose that mature chromatin is formed in a two-step reaction. In the first step, nucleosome deposition occurs independently of ATP and Mg2+. Thus, nucleosome formation can be uncoupled from their spacing. In this step, topoisomerase activity is involved in the relaxation of the topological constraints generated by chromatin assembly rather than in the process of assembly itself. The second step, requiring ATP and Mg2+, generates properly spaced chromatin. Images PMID:2854062

  8. Remote Maneuver of Space Debris Using Photon Pressure for Active Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Smith, C.

    2014-09-01

    The Space Environment Research Corporation (SERC) is a consortium of companies and research institutions that have joined together to pursue research and development of technologies and capabilities that will help to preserve the orbital space environment. The consortium includes, Electro Optics Systems (Australia), Lockheed Martin Australia, Optus Satellite Systems (Australia), The Australian national University, RMIT University, National Institute of Information and Communications Technology (NICT, Japan) as well as affiliates from NASA Ames and ESA. SERC is also the recipient of and Australian Government Cooperative Research Centre grant. SERC will pursue a wide ranging research program including technologies to improve tracking capability and capacity, orbit determination and propagation algorithms, conjunction analysis and collision avoidance. All of these technologies will contribute to the flagship program to demonstrate active collision avoidance using photon pressure to provide remote maneuver of space debris. This project joins of the proposed NASA Lightforce concept with infrastructure and capabilities provided by SERC. This paper will describe the proposed research and development program to provide an on-orbit demonstration within the next five years for remote maneuver of space debris.

  9. Identification of SFBB-containing canonical and noncanonical SCF complexes in pollen of apple (Malus × domestica).

    PubMed

    Minamikawa, Mai F; Koyano, Ruriko; Kikuchi, Shinji; Koba, Takato; Sassa, Hidenori

    2014-01-01

    Gametophytic self-incompatibility (GSI) of Rosaceae, Solanaceae and Plantaginaceae is controlled by a single polymorphic S locus. The S locus contains at least two genes, S-RNase and F-box protein encoding gene SLF/SFB/SFBB that control pistil and pollen specificity, respectively. Generally, the F-box protein forms an E3 ligase complex, SCF complex with Skp1, Cullin1 (CUL1) and Rbx1, however, in Petunia inflata, SBP1 (S-RNase binding protein1) was reported to play the role of Skp1 and Rbx1, and form an SCFSLF-like complex for ubiquitination of non-self S-RNases. On the other hand, in Petunia hybrida and Petunia inflata of Solanaceae, Prunus avium and Pyrus bretschneideri of Rosaceae, SSK1 (SLF-interacting Skp1-like protein1) is considered to form the SCFSLF/SFB complex. Here, we isolated pollen-expressed apple homologs of SSK1 and CUL1, and named MdSSK1, MdCUL1A and MdCUL1B. MdSSK1 was preferentially expressed in pollen, but weakly in other organs analyzed, while, MdCUL1A and MdCUL1B were almost equally expressed in all the organs analyzed. MdSSK1 transcript abundance was significantly (>100 times) higher than that of MdSBP1. In vitro binding assays showed that MdSSK1 and MdSBP1 interacted with MdSFBB1-S9 and MdCUL1, and MdSFBB1-S9 interacted more strongly with MdSSK1 than with MdSBP1. The results suggest that both MdSSK1-containing SCFSFBB1 and MdSBP1-containing SCFSFBB1-like complexes function in pollen of apple, and the former plays a major role. PMID:24847858

  10. Semi-active damping of large space truss structures using friction joints

    NASA Astrophysics Data System (ADS)

    Gaul, Lothar; Albrecht, Hans; Wirnitzer, Jan

    2002-11-01

    The low structural damping of large space structures and the stringent positioning requirements in missions demand effective vibration suppression. The semi-active approach at hand is based on friction damping due to interfacial slip in semi-active joints which can be controlled by varying the normal pressure in the contact area using a piezo-stack actuator. This paper focuses on the modeling, identification and model reduction of a large space structure with semi-active joints. For the purpose of model identification and model reduction, the nonlinear friction forces transmitted in the joints are considered as external forces acting on the linear tress structure. Experimental Modal Analysis results are used to update the FE model of the truss structure and the parameters of the nonlinear friction model are identified from measured responses of an isolated joint. The model of the linear subsystem is reduced by a combination of balanced reduction and matching moments method. The modal truncation is based on controllability and observability gramians. To improve the fidelity locations conventional connections are replaced by adaptive joints, each with a local feedback controller for the adaptation of the normal force. Simulation results of a 10-bay truss structure with semi-active joints show the potential of the present approach.

  11. Improving realtime predictions of magnetospheric activities using STEREO Space Weather Beacon

    NASA Astrophysics Data System (ADS)

    Bala, R.; Reiff, P. H.

    2011-12-01

    The Rice neural network models of geomagnetic activity indices Kp, Dst and AE (available from \\url{http://mms.rice.edu/realtime/forecast.html}), driven by the ACE solar wind data, have been actively running in near-realtime mode to provide short-term predictions of magnetospheric activities; subscribers to our ``spacalrt" system receive email alerts and notices of space weather based on key discriminator levels. Active structures that are likely to erupt on the sun and resulting in solar flares and/or Coronal Mass Ejections (CMEs) are now being well imaged by instruments aboard STEREO, which also provides multipoint, realtime and continuous information of the solar wind, interplanetary magnetic field, solar energetic particles through its Space Weather Beacon IMPACT and PLASTIC. The spacecraft lagging Earth (STEREO-B) and being ahead in the Parker spiral, is well suited to provide longer lead times to predictions of any common measures of geoeffectiveness resulting from solar wind-magnetospheric interactions such as Kp, Dst and AE indices. As our models are constantly evolving, our desire to drive them by indulging these advanced instruments is to provide longer lead times. Furthermore, this paper also investigates the geoeffectiveness of predicting CME-driven storms.

  12. Space suit bioenergetics: framework and analysis of unsuited and suited activity.

    PubMed

    Carr, Christopher E; Newman, Dava J

    2007-11-01

    Metabolic costs limit the duration and intensity of extravehicular activity (EVA), an essential component of future human missions to the Moon and Mars. Energetics Framework: We present a framework for comparison of energetics data across and between studies. This framework, applied to locomotion, differentiates between muscle efficiency and energy recovery, two concepts often confused in the literature. The human run-walk transition in Earth gravity occurs at the point for which energy recovery is approximately the same for walking and running, suggesting a possible role for recovery in gait transitions. Muscular Energetics: Muscle physiology limits the overall efficiency by which chemical energy is converted through metabolism to useful work. Unsuited Locomotion: Walking and running use different methods of energy storage and release. These differences contribute to the relative changes in the metabolic cost of walking and running as gravity is varied, with the metabolic cost of locomoting at a given velocity changing in proportion to gravity for running and less than in proportion for walking. Space Suits: Major factors affecting the energetic cost of suited movement include suit pressurization, gravity, velocity, surface slope, and space suit configuration. Apollo lunar surface EVA traverse metabolic rates, while unexpectedly low, were higher than other activity categories. The Lunar Roving Vehicle facilitated even lower metabolic rates, thus longer duration EVAs. Muscles and tendons act like springs during running; similarly, longitudinal pressure forces in gas pressure space suits allow spring-like storage and release of energy when suits are self-supporting. PMID:18018432

  13. Definition of the Active Cooling System for the Space Instrument CIVA/Mars

    NASA Astrophysics Data System (ADS)

    Lamartinie, Sujit; Bibring, Jean-Pierre; Soufflot, Alain

    2003-03-01

    CIVA/Mars is a space miniaturized spectral imaging microscope. It is designed to in-situ analyze samples on Mars surface. It requires the use of a double cooling system : a passive cooling for the global instrument which will be maintained at a temperature higher than 160 K and an active cooling system for the IR MCT detector matrix which must be maintained at a temperature lower than 140 K. Taking into account the mission constraints, a trade-off analysis of available active cooling systems led to the choice of a thermoelectrical cooler (TEC). Space validation tests of standard multi-stage TECs were performed. Performances did not meet the technical specifications of the instrument. Two types of customized TEC modules were then designed and manufactured : mechanical prototypes from RMT Ltd. and optimized modules from Marlow Ind. A first RMT prototype passed the vibration &shock qualification tests and a second passed the low temperatures vacuum qualification tests with few margins. A Marlow optimized module passed the low temperatures vacuum qualification tests; its characteristics and performances make it compatible with CIVA/Mars. In this paper, the instrument mission and characteristics are first presented. Then TEC design studies are discussed. Finally, optimized TEC space qualification tests are detailed, and the performances analyzed.

  14. Active pore space utilization in nanoporous carbon-based supercapacitors: Effects of conductivity and pore accessibility

    NASA Astrophysics Data System (ADS)

    Seredych, Mykola; Koscinski, Mikolaj; Sliwinska-Bartkowiak, Malgorzata; Bandosz, Teresa J.

    2012-12-01

    Composites of commercial graphene and nanoporous sodium-salt-polymer-derived carbons were prepared with 5 or 20 weight% graphene. The materials were characterized using the adsorption of nitrogen, SEM/EDX, thermal analysis, Raman spectroscopy and potentiometric titration. The samples' conductivity was also measured. The performance of the carbon composites in energy storage was linked to their porosity and electronic conductivity. The small pores (<0.7) were found as very active for double layer capacitance. It was demonstrated that when double layer capacitance is a predominant mechanism of charge storage, the degree of the pore space utilization for that storage can be increased by increasing the conductivity of the carbons. That active pore space utilization is defined as gravimetric capacitance per unit pore volume in pores smaller than 0.7 nm. Its magnitude is affected by conductivity of the carbon materials. The functional groups, besides pseudocapacitive contribution, increased the wettability and thus the degree of the pore space utilization. Graphene phase, owing to its conductivity, also took part in an insitu increase of the small pore accessibility and thus the capacitance of the composites via enhancing an electron transfer to small pores and thus imposing the reduction of groups blocking the pores for electrolyte ions.

  15. NASA safety program activities in support of the Space Exploration Initiatives Nuclear Propulsion program

    NASA Technical Reports Server (NTRS)

    Sawyer, J. C., Jr.

    1993-01-01

    The activities of the joint NASA/DOE/DOD Nuclear Propulsion Program Technical Panels have been used as the basis for the current development of safety policies and requirements for the Space Exploration Initiatives (SEI) Nuclear Propulsion Technology development program. The Safety Division of the NASA Office of Safety and Mission Quality has initiated efforts to develop policies for the safe use of nuclear propulsion in space through involvement in the joint agency Nuclear Safety Policy Working Group (NSPWG), encouraged expansion of the initial policy development into proposed programmatic requirements, and suggested further expansion into the overall risk assessment and risk management process for the NASA Exploration Program. Similar efforts are underway within the Department of Energy to ensure the safe development and testing of nuclear propulsion systems on Earth. This paper describes the NASA safety policy related to requirements for the design of systems that may operate where Earth re-entry is a possibility. The expected plan of action is to support and oversee activities related to the technology development of nuclear propulsion in space, and support the overall safety and risk management program being developed for the NASA Exploration Program.

  16. Protective clothing textile research for space activities in the 1980's

    NASA Technical Reports Server (NTRS)

    Radnofsky, M. I.; Kosmo, J. J.

    1980-01-01

    Textile and clothing specifications for space activities are discussed, emphasizing a chronological and utilitarian role. New fabrication techniques led to the Mercury Space Suit, a constant-wear hybrid of the omni-environmental full pressure suit used by high-flying pilots of the 1950s. The Gemini program (1964-1966) provided the first specifically designed protective clothing assembly for both intra- and extravehicular operations. The G4C, used for EV (extravehicular) activities, protected the astronaut against solar radiation, heat loss, and meteoroid penetration. The clothing for the Apollo program (1968-1975) mirrored a greater concern for fire safety with Durette (a halogenated polyamide) and PBI (polybenzimadazole) widely used for intravehicular garments. With the advent of the Shuttle program, cabin pressure and composition were changed from 6 psi, 100% oxygen to 9-14 psi, 23.4% oxygen, 76.6% N2. As a result, 'off-the-shelf' materials were used without compromising fire safety. Reusability was stressed, as textile costs and durability were now important selection criteria noting that existing textile materials will probably be adequate for the next 20 years of space operations and research. A portable lunar survival shelter made of textiles is being developed; and a preliminary design for an EV 'tunnel suit system' (an access tunnel and homoform work station) is already in existence.

  17. The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 2

    NASA Technical Reports Server (NTRS)

    Mendell, Wendell W. (Editor); Alred, John W. (Editor); Bell, Larry S. (Editor); Cintala, Mark J. (Editor); Crabb, Thomas M. (Editor); Durrett, Robert H. (Editor); Finney, Ben R. (Editor); Franklin, H. Andrew (Editor); French, James R. (Editor); Greenberg, Joel S. (Editor)

    1992-01-01

    These 92 papers comprise a peer-reviewed selection of presentations by authors from NASA, the Lunar and Planetary Institute (LPI), industry, and academia at the Second Conference on Lunar Bases and Space Activities of the 21st Century. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics included the following: (1) design and operation of transportation systems to, in orbit around, and on the Moon; (2) lunar base site selection; (3) design, architecture, construction, and operation of lunar bases and human habitats; (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology; (5) recovery and use of lunar resources; (6) environmental and human factors of and life support technology for human presence on the Moon; and (7) program management of human exploration of the Moon and space.

  18. Cluster spacecraft observations of a ULF wave enhanced by Space Plasma Exploration by Active Radar (SPEAR)

    NASA Astrophysics Data System (ADS)

    Badman, S. V.; Wright, D. M.; Clausen, L. B. N.; Fear, R. C.; Robinson, T. R.; Yeoman, T. K.

    2009-09-01

    Space Plasma Exploration by Active Radar (SPEAR) is a high-latitude ionospheric heating facility capable of exciting ULF waves on local magnetic field lines. We examine an interval from 1 February 2006 when SPEAR was transmitting a 1 Hz modulation signal with a 10 min on-off cycle. Ground magnetometer data indicated that SPEAR modulated currents in the local ionosphere at 1 Hz, and enhanced a natural field line resonance with a 10 min period. During this interval the Cluster spacecraft passed over the heater site. Signatures of the SPEAR-enhanced field line resonance were present in the magnetic field data measured by the magnetometer on-board Cluster-2. These are the first joint ground- and space-based detections of field line tagging by SPEAR.

  19. Open Discussion Session: Challenges and Advancements in Coordinated Space Weather Activities

    NASA Astrophysics Data System (ADS)

    Kauristie, Kirsti

    2016-07-01

    Besides addressing the key questions in space weather research the Cospar/ILWS Roadmap presents also recommendations for teaming in the research environment and for collaboration between agencies and communities. Coordinated work of different research groups facilitate our efforts for a holistic view on the entire Sun-Earth system with its complicated feedback processes in different scale sizes. Seamless knowledge transfer from research to operational services is a crucial factor for the success of space weather research field. In this open discussion session we encourage the participants to share their views on most important challenges and advancements in our field, both in science and in collaboration. We also welcome comments on the roadmap recommendations and guidance for similar activities in the future.

  20. Integrated Modeling Activities for the James Webb Space Telescope: Structural-Thermal-Optical Analysis

    NASA Technical Reports Server (NTRS)

    Johnston, John D.; Howard, Joseph M.; Mosier, Gary E.; Parrish, Keith A.; McGinnis, Mark A.; Bluth, Marcel; Kim, Kevin; Ha, Kong Q.

    2004-01-01

    The James Web Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2011. This is a continuation of a series of papers on modeling activities for JWST. The structural-thermal-optical, often referred to as STOP, analysis process is used to predict the effect of thermal distortion on optical performance. The benchmark STOP analysis for JWST assesses the effect of an observatory slew on wavefront error. Temperatures predicted using geometric and thermal math models are mapped to a structural finite element model in order to predict thermally induced deformations. Motions and deformations at optical surfaces are then input to optical models, and optical performance is predicted using either an optical ray trace or a linear optical analysis tool. In addition to baseline performance predictions, a process for performing sensitivity studies to assess modeling uncertainties is described.

  1. Space Environments and Effects (SEE) Program: Spacecraft Charging Technology Development Activities

    NASA Technical Reports Server (NTRS)

    Kauffman, Billy; Hardage, Donna; Minor, Jody

    2003-01-01

    Reducing size and weight of spacecraft, along with demanding increased performance capabilities, introduces many uncertainties in the engineering design community on how materials and spacecraft systems will perform in space. The engineering design community is forever behind on obtaining and developing new tools and guidelines to mitigate the harmful effects of the space environment. Adding to this complexity is the continued push to use Commercial-off-the-shelf (COTS) microelectronics, potential usage of unproven technologies such as large solar sail structures and nuclear electric propulsion. In order to drive down these uncertainties, various programs are working together to avoid duplication, save what resources are available in this technical area and possess a focused agenda to insert these new developments into future mission designs. This paper will introduce the SEE Program, briefly discuss past and currently sponsored spacecraft charging activities and possible future endeavors.

  2. Space Environments and Effects (SEE) Program: Spacecraft Charging Technology Development Activities

    NASA Technical Reports Server (NTRS)

    Kauffman, B.; Hardage, D.; Minor, J.

    2004-01-01

    Reducing size and weight of spacecraft, along with demanding increased performance capabilities, introduces many uncertainties in the engineering design community on how materials and spacecraft systems will perform in space. The engineering design community is forever behind on obtaining and developing new tools and guidelines to mitigate the harmful effects of the space environment. Adding to this complexity is the continued push to use Commercial-off-the-Shelf (COTS) microelectronics, potential usage of unproven technologies such as large solar sail structures and nuclear electric propulsion. In order to drive down these uncertainties, various programs are working together to avoid duplication, save what resources are available in this technical area and possess a focused agenda to insert these new developments into future mission designs. This paper will introduce the SEE Program, briefly discuss past and currently sponsored spacecraft charging activities and possible future endeavors.

  3. Integrated failure detection and management for the Space Station Freedom external active thermal control system

    NASA Astrophysics Data System (ADS)

    Mesloh, Nick; Hill, Tim; Kosyk, Kathy

    This paper presents the integrated approach toward failure detection, isolation, and recovery/reconfiguration to be used for the Space Station Freedom External Active Thermal Control System (EATCS). The on-board and on-ground diagnostic capabilities of the EATCS are discussed. Time and safety critical features, as well as noncritical failures, and the detection coverage for each provided by existing capabilities are reviewed. The allocation of responsibility between on-board software and ground-based systems, to be shown during ground testing at the Johnson Space Center, is described. Failure isolation capabilities allocated to the ground include some functionality originally found on orbit but moved to the ground to reduce on-board resource requirements. Complex failures requiring the analysis of multiple external variables, such as environmental conditions, heat loads, or station attitude, are also allocated to ground personnel.

  4. Integrated failure detection and management for the Space Station Freedom external active thermal control system

    NASA Technical Reports Server (NTRS)

    Mesloh, Nick; Hill, Tim; Kosyk, Kathy

    1993-01-01

    This paper presents the integrated approach toward failure detection, isolation, and recovery/reconfiguration to be used for the Space Station Freedom External Active Thermal Control System (EATCS). The on-board and on-ground diagnostic capabilities of the EATCS are discussed. Time and safety critical features, as well as noncritical failures, and the detection coverage for each provided by existing capabilities are reviewed. The allocation of responsibility between on-board software and ground-based systems, to be shown during ground testing at the Johnson Space Center, is described. Failure isolation capabilities allocated to the ground include some functionality originally found on orbit but moved to the ground to reduce on-board resource requirements. Complex failures requiring the analysis of multiple external variables, such as environmental conditions, heat loads, or station attitude, are also allocated to ground personnel.

  5. The second conference on lunar bases and space activities of the 21st Century, volume 2

    SciTech Connect

    Mendell, W.W.; Alred, J.W.; Bell, L.S.; Cintala, M.J.; Crabb, T.M.; Durrett, R.H.; Finney, B.R.; Franklin, H.A.; French, J.R.; Greenberg, J.S.

    1992-09-01

    These 92 papers comprise a peer-reviewed selection of presentations by authors from NASA, the Lunar and Planetary Institute (LPI), industry, and academia at the Second Conference on Lunar Bases and Space Activities of the 21st Century. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics included the following: (1) design and operation of transportation systems to, in orbit around, and on the Moon; (2) lunar base site selection; (3) design, architecture, construction, and operation of lunar bases and human habitats; (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology; (5) recovery and use of lunar resources; (6) environmental and human factors of and life support technology for human presence on the Moon; and (7) program management of human exploration of the Moon and space. Separate abstracts have been prepared for articles in this report.

  6. Near Term Effects from Satellite Break-Ups on Manned Space Activities

    NASA Technical Reports Server (NTRS)

    Theall, J. R.; Matney, M. J.

    2000-01-01

    Since 1961, almost 160 satellite break-ups have occurred on-orbit, and have been the major contributor to the growth of the orbital debris population. When a satellite breaks up, the debris exists in a relatively concentrated form, orbiting in a loose cloud with the parent body until orbital perturbations disperse the cloud into the average background. Manned space activities, which usually take place in low Earth orbit at altitudes less than 500 km, have been continuous for the past I I years while Mir was inhabited and promise to be again continuous when the International Space Station becomes permanently manned. This paper surveys historical breakups over the last I I years to determine the number that affect altitudes lower than 500 km. Selected breakup are analyzed using NASA's Satellite Breakup Risk Assessment Model (SBRAM) to determine the specific short term risk from those breakups to manned missions.

  7. Activation of the E1 Ultra High Pressure Propulsion Test Facility at Stennis Space Center

    NASA Technical Reports Server (NTRS)

    Messer, Bradley; Messer, Elisabeth; Sewell, Dale; Sass, Jared; Lott, Jeff; Dutreix, Lionel, III

    2001-01-01

    After a decade of construction and a year of activation the El Ultra High Pressure Propulsion Test Facility at NASA's Stennis Space Center is fully operational. The El UHP Propulsion Test Facility is a multi-cell, multi-purpose component and engine test facility . The facility is capable of delivering cryogenic propellants at low, high, and ultra high pressures with flow rates ranging from a few pounds per second up to two thousand pounds per second. Facility activation is defined as a series of tasks required to transition between completion of construction and facility operational readiness. Activating the El UHP Propulsion Test Facility involved independent system checkouts, propellant system leak checks, fluid and gas sampling, gaseous system blow downs, pressurization and vent system checkouts, valve stability testing, valve tuning cryogenic cold flows, and functional readiness tests.

  8. Utilizing Participatory Mapping and GIS to Examine the Activity Spaces of Homeless Youth.

    PubMed

    Townley, Greg; Pearson, L; Lehrwyn, Josephine M; Prophet, Nicole T; Trauernicht, Mareike

    2016-06-01

    Although previous studies have informed our understanding of certain aspects of youth homelessness, few studies have critically examined the spatial and social environments utilized by youth as they navigate life on the streets. This study employed participatory mapping and Geographic Information Systems (GIS) to examine the activity spaces of homeless youth as they relate to sense of community and psychological well-being. Participants were 28 youth experiencing homelessness in Portland, Oregon, USA. Results suggest that youth engage most frequently in service-related activities, and their activity participation is significantly associated with sense of community and psychological well-being. The utility of innovative participatory methods for better understanding the diverse experiences of homeless youth is discussed alongside examination of their practical implications. PMID:27219497

  9. Moving Beyond Neighborhood: Activity Spaces and Ecological Networks As Contexts for Youth Development

    PubMed Central

    Browning, Christopher R.; Soller, Brian

    2014-01-01

    Many scholars, policy analysts, and practitioners agree that neighborhoods are important contexts for urban youth. Yet, despite decades of research, our knowledge of why and how neighborhoods influence the day-to-day lives of youth is still emerging. Theories about neighborhood effects largely assume that neighborhoods operate to influence youth through exposure-based mechanisms. Extant theoretical approaches, however, have neglected the processes by which neighborhood socioeconomic contexts influence the routine spatial exposures—or activity spaces—of urban residents. In this article, we argue that exposure to organizations, institutions, and other settings that characterize individual activity spaces is a key mechanism through which neighborhoods influence youth outcomes. Moreover, we hypothesize that aggregate patterns of shared local exposure—captured by the concept of ecological networks—are influenced by neighborhood socioeconomic characteristics and are independently consequential for neighborhood youth. Neighborhoods in which residents intersect in space more extensively as a result of routine conventional activities will exhibit higher levels of social capital relevant to youth well-being, including (1) familiarity, (2) beneficial (weak) social ties, (3) trust, (4) shared expectations for pro-social youth behavior (collective efficacy), and (5) the capacity for consistent monitoring of public space. We then consider the implications of ecological networks for understanding the complexities of contextual exposure. We specifically discuss the role of embeddedness in ecological communities—that is, clusters of actors and locations that intersect at higher rates—for understanding contextual influences that are inadequately captured by geographically defined neighborhoods. We conclude with an overview of new approaches to data collection that incorporate insights from an activity-space and ecological-network perspective on neighborhood and

  10. Tracking and visualization of space-time activities for a micro-scale flu transmission study

    PubMed Central

    2013-01-01

    Background Infectious diseases pose increasing threats to public health with increasing population density and more and more sophisticated social networks. While efforts continue in studying the large scale dissemination of contagious diseases, individual-based activity and behaviour study benefits not only disease transmission modelling but also the control, containment, and prevention decision making at the local scale. The potential for using tracking technologies to capture detailed space-time trajectories and model individual behaviour is increasing rapidly, as technological advances enable the manufacture of small, lightweight, highly sensitive, and affordable receivers and the routine use of location-aware devices has become widespread (e.g., smart cellular phones). The use of low-cost tracking devices in medical research has also been proved effective by more and more studies. This study describes the use of tracking devices to collect data of space-time trajectories and the spatiotemporal processing of such data to facilitate micro-scale flu transmission study. We also reports preliminary findings on activity patterns related to chances of influenza infection in a pilot study. Methods Specifically, this study employed A-GPS tracking devices to collect data on a university campus. Spatiotemporal processing was conducted for data cleaning and segmentation. Processed data was validated with traditional activity diaries. The A-GPS data set was then used for visual explorations including density surface visualization and connection analysis to examine space-time activity patterns in relation to chances of influenza infection. Results When compared to diary data, the segmented tracking data demonstrated to be an effective alternative and showed greater accuracies in time as well as the details of routes taken by participants. A comparison of space-time activity patterns between participants who caught seasonal influenza and those who did not revealed interesting

  11. Space Weather Activities at SERC for IHY : Magnetic Data Acquisition System (MAGDAS)

    NASA Astrophysics Data System (ADS)

    Yumoto, K.; Magdas/Cpmn Group

    2006-11-01

    arnoldyuki@serc.kyushu-u.ac.jp One purpose of Solar Terrestrial Physics (STP) research in the twenty-first century is to support human activities in Space from the aspect of basic research. The scientific aim of the STP community is the creation of new physics: (1) couplings of the complex and composite systems and (2) macro-and-micro-scale couplings in the Solar-Planetary system. The intention is to construct a new Network of Stations for ground-based observations and for simulations/empirical modeling. The Space Environment Research Center (SERC), Kyushu University, is currently deploying a new ground-based magnetometer network, in cooperation with about 30 organizations around the world, in order to study the complex Sun-Earth system for space weather. SERC conducts MAGDAS (MAGnetic Data Acquisition System) observation at 50 stations in the CPMN (Circum-pan Pacific Magnetometer Network) region, and conducts frequency modulated continuous wave (FM-CW) radar observation along the 210° magnetic meridian during the IHY/IPY/eGY/ ILWS/CAWSES periods. From these network observations, we will clarify: (1) The dynamics of plasmaspheric changes during space storms and substorms, (2) Electromagnetic responses of magnetosphere-ionosphere-thermosphere complex system to various solar wind changes, and (3) penetration mechanisms of DP2-ULF range disturbances from the solar wind into the equatorial ionosphere. In the present paper, we will first introduce our real-time data acquisition and analysis system of MAGDAS/CPMN, which was deployed in 2005 and 2006, and preliminary results from the MAGDAS project. This project is actively providing the following: (1) Monitoring the global 3-dimensional current system to know the electromagnetic coupling of high-latitude and Sq current systems, and (2) Monitoring of the plasma density to understand space plasma environment change during space storms. We will also present our FM-CW radar system at L=1.26 to deduce the electric field from

  12. An economic benefit deriving from space activities: Integration between science institutions and industry

    NASA Astrophysics Data System (ADS)

    Monti, R.; D'Amore, M.; D'Angelo, L.

    1993-09-01

    MARS Center experiences, a great improvement of the integration has been identified as a consequence of the European and national expenditure in this area of space activities. An estimate of the previously stated issues will be performed on a meaningful set of programmes funded on a European and National basis.

  13. Spaced education activates students in a theoretical radiological science course: a pilot study

    PubMed Central

    2012-01-01

    Background The present study aimed at determining if the addition of spaced education to traditional face-to-face lectures increased the time students kept busy with the learning content of a theoretical radiological science course. Methods The study comprised two groups of 21 third-year dental students. The students were randomly assigned to a “traditional group” and a “spaced education group”. Both groups followed a traditional face-to-face course. The intervention in the spaced education group was performed in way that these students received e-mails with a delay of 14 days to each face-to-face lecture. These e-mails contained multiple choice questions on the learning content of the lectures. The students returned their answers to the questions also by e-mail. On return they received an additional e-mail that included the correct answers and additional explanatory material. All students of both groups documented the time they worked on the learning content of the different lectures before a multiple choice exam was held after the completion of the course. All students of both groups completed the TRIL questionnaire (Trierer Inventar zur Lehrevaluation) for the evaluation of courses at university after the completion of the course. The results for the time invested in the learning content and the results of the questionnaire for the two groups were compared using the Mann–Whitney-U test. Results The spaced education group spent significantly more time (216.2 ± 123.9 min) on keeping busy with the learning content compared to the traditional group (58.4 ± 94.8 min, p < .0005). The spaced education group rated the didactics of the course significantly better than the traditional group (p = .034). The students of the spaced education group also felt that their needs were fulfilled significantly better compared to the traditional group as far as communication with the teacher was concerned (p = .022). Conclusions Adding spaced

  14. What's up? Emotion-specific activation of vertical space during language processing.

    PubMed

    Dudschig, Carolin; de la Vega, Irmgard; Kaup, Barbara

    2015-03-01

    The relationship between language processing and vertical space has been shown for various groups of words including valence words, implicit location words, and words referring to religious concepts. However, it remains unclear whether these are single phenomena or whether there is an underlying common mechanism. Here, we show that the evaluation of word valence interacts with motor responses in the vertical dimension, with positive (negative) evaluations facilitating upward (downward) responses. When valence evaluation was not required, implicit location words (e.g., bird, shoe) influenced motor responses whereas valence words (e.g., kiss, hate) did not. Importantly, a subset of specific emotional valence words that are commonly associated with particular bodily postures (e.g., proud→upright; sad→slouched) did automatically influence motor responses. Together, this suggests that while the vertical spatial dimension is not directly activated by word valence, it is activated when processing words referring to emotional states with stereotypical bodily-postures. These results provide strong evidence that the activation of spatial associations during language processing is experience-specific in nature and cannot be explained with reference to a general mapping between all valence words and space (i.e., all positive and negative words generally relate to spatial processing). These findings support the experiential view of language comprehension, suggesting that the automatic reactivation of bodily experiences is limited to word groups referring to emotions or entities directly associated with spatial experiences (e.g., posture or location in the world). PMID:25454886

  15. Disentangling AGN and Star Formation Activity at High Redshift Using Hubble Space Telescope Grism Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bridge, Joanna S.; Zeimann, Gregory R.; Trump, Jonathan R.; Gronwall, Caryl; Ciardullo, Robin; Fox, Derek; Schneider, Donald P.

    2016-08-01

    Differentiating between active galactic nucleus (AGN) activity and star formation in z ∼ 2 galaxies is difficult because traditional methods, such as line-ratio diagnostics, change with redshift, while multi-wavelength methods (X-ray, radio, IR) are sensitive to only the brightest AGNs. We have developed a new method for spatially resolving emission lines using the Hubble Space Telescope/Wide Field Camera 3 G141 grism spectra and quantifying AGN activity through the spatial gradient of the [O iii]/Hβ line ratio. Through detailed simulations, we show that our novel line-ratio gradient approach identifies ∼40% more low-mass and obscured AGNs than obtained by classical methods. Based on our simulations, we developed a relationship that maps the stellar mass, star formation rate, and measured [O iii]/Hβ gradient to the AGN Eddington ratio. We apply our technique to previously studied stacked samples of galaxies at z ∼ 2 and find that our results are consistent with these studies. This gradient method will also be able to inform other areas of galaxy evolution science, such as inside-out quenching and metallicity gradients, and will be widely applicable to future spatially resolved James Webb Space Telescope data.

  16. Online Damage Detection on Metal and Composite Space Structures by Active and Passive Acoustic Methods

    NASA Astrophysics Data System (ADS)

    Scheerer, M.; Cardone, T.; Rapisarda, A.; Ottaviano, S.; Ftancesconi, D.

    2012-07-01

    In the frame of ESA funded programme Future Launcher Preparatory Programme Period 1 “Preparatory Activities on M&S”, Aerospace & Advanced Composites and Thales Alenia Space-Italia, have conceived and tested a structural health monitoring approach based on integrated Acoustic Emission - Active Ultrasound Damage Identification. The monitoring methods implemented in the study are both passive and active methods and the purpose is to cover large areas with a sufficient damage size detection capability. Two representative space sub-structures have been built and tested: a composite overwrapped pressure vessel (COPV) and a curved, stiffened Al-Li panel. In each structure, typical critical damages have been introduced: delaminations caused by impacts in the COPV and a crack in the stiffener of the Al-Li panel which was grown during a fatigue test campaign. The location and severity of both types of damages have been successfully assessed online using two commercially available systems: one 6 channel AE system from Vallen and one 64 channel AU system from Acellent.

  17. Space Active Optics: toward optimized correcting mirrors for future large spaceborne observatories

    NASA Astrophysics Data System (ADS)

    Laslandes, Marie; Hugot, Emmanuel; Ferrari, Marc; Lemaitre, Gérard; Liotard, Arnaud

    2011-10-01

    Wave-front correction in optical instruments is often needed, either to compensate Optical Path Differences, off-axis aberrations or mirrors deformations. Active optics techniques are developed to allow efficient corrections with deformable mirrors. In this paper, we will present the conception of particular deformation systems which could be used in space telescopes and instruments in order to improve their performances while allowing relaxing specifications on the global system stability. A first section will be dedicated to the design and performance analysis of an active mirror specifically designed to compensate for aberrations that might appear in future 3m-class space telescopes, due to lightweight primary mirrors, thermal variations or weightless conditions. A second section will be dedicated to a brand new design of active mirror, able to compensate for given combinations of aberrations with a single actuator. If the aberrations to be corrected in an instrument and their evolutions are known in advance, an optimal system geometry can be determined thanks to the elasticity theory and Finite Element Analysis.

  18. Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration.

    PubMed

    Narici, Livio; Berger, Thomas; Matthiä, Daniel; Reitz, Günther

    2015-01-01

    A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation. PMID:26697408

  19. Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration

    PubMed Central

    Narici, Livio; Berger, Thomas; Matthiä, Daniel; Reitz, Günther

    2015-01-01

    A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation. PMID:26697408

  20. Disentangling AGN and Star Formation Activity at High Redshift Using Hubble Space Telescope Grism Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bridge, Joanna S.; Zeimann, Gregory R.; Trump, Jonathan R.; Gronwall, Caryl; Ciardullo, Robin; Fox, Derek; Schneider, Donald P.

    2016-08-01

    Differentiating between active galactic nucleus (AGN) activity and star formation in z ˜ 2 galaxies is difficult because traditional methods, such as line-ratio diagnostics, change with redshift, while multi-wavelength methods (X-ray, radio, IR) are sensitive to only the brightest AGNs. We have developed a new method for spatially resolving emission lines using the Hubble Space Telescope/Wide Field Camera 3 G141 grism spectra and quantifying AGN activity through the spatial gradient of the [O iii]/Hβ line ratio. Through detailed simulations, we show that our novel line-ratio gradient approach identifies ˜40% more low-mass and obscured AGNs than obtained by classical methods. Based on our simulations, we developed a relationship that maps the stellar mass, star formation rate, and measured [O iii]/Hβ gradient to the AGN Eddington ratio. We apply our technique to previously studied stacked samples of galaxies at z ˜ 2 and find that our results are consistent with these studies. This gradient method will also be able to inform other areas of galaxy evolution science, such as inside-out quenching and metallicity gradients, and will be widely applicable to future spatially resolved James Webb Space Telescope data.

  1. Antenna gain of actively compensated free-space optical communication systems under strong turbulence conditions.

    PubMed

    Juarez, Juan C; Brown, David M; Young, David W

    2014-05-19

    Current Strehl ratio models for actively compensated free-space optical communications terminals do not accurately predict system performance under strong turbulence conditions as they are based on weak turbulence theory. For evaluation of compensated systems, we present an approach for simulating the Strehl ratio with both low-order (tip/tilt) and higher-order (adaptive optics) correction. Our simulation results are then compared to the published models and their range of turbulence validity is assessed. Finally, we propose a new Strehl ratio model and antenna gain equation that are valid for general turbulence conditions independent of the degree of compensation. PMID:24921373

  2. Influence of Space-Flight Factors on the Properties of Microorganisms, Producers of Biologically Active Substances

    NASA Astrophysics Data System (ADS)

    Krasheninnikova, T. K.; Kanaeva, E. N.; Ukraintsev, A. D.; Smolyanaya, G. L.; Kuznetsov, N. V.; Panasyuk, M. I.; Shcherbakov, G. Ya.

    2001-07-01

    The following substances were isolated under the influence of space-flight factors in cosmic experiments aboard the Mirorbital station: an MIB-90 monoisolant, which is distinguished by its morphological and biochemical properties and enhanced productivity, was isolated from the Bacillus thuringiensis ssp. Kurstaki var. Z-52culture, which is a producer of the plant protection agent Lepidocide; and MIA-74 and MIP-89 monoisolants, which are highly active toward heavy petroleum fractions (C23 C33), were isolated from the Arthrobacter OC-1culture, which is a producer of biodegradants for petroleum.

  3. US space flight experience. Physical exertion and metabolic demand of extravehicular activity: Past, present, and future

    NASA Technical Reports Server (NTRS)

    Moore, Thomas P.

    1989-01-01

    A review of physical exertion and metabolic demands of extravehicular activity (EVA) on U.S. astronauts is given. Information is given on EVA during Gemini, Apollo and Skylab missions. It is noted that nominal EVA's should not be overstressful from a cardiovascular standpoint; that manual-intensive EVA's such as are planned for the construction phase of the Space Station can and will be demanding from a muscular standpoint, primarily for the upper extremities; that off-nominal unplanned EVA's can be physically demanding both from an endurance and from a muscular standpoint; and that crewmembers should be physically prepared and capable of performing these EVA's at any time during the mission.

  4. Parylene-based active micro space radiator with thermal contact switch

    SciTech Connect

    Ueno, Ai; Suzuki, Yuji

    2014-03-03

    Thermal management is crucial for highly functional spacecrafts exposed to large fluctuations of internal heat dissipation and/or thermal boundary conditions. Since thermal radiation is the only means for heat removal, effective control of radiation is required for advanced space missions. In the present study, a MEMS (Micro Electro Mechanical Systems) active radiator using the contact resistance change has been proposed. Unlike previous bulky thermal louvers/shutters, higher fill factor can be accomplished with an array of electrostatically driven micro diaphragms suspended with polymer tethers. With an early prototype developed with parylene MEMS technologies, radiation heat flux enhancement up to 42% has been achieved.

  5. Active cleaning techniques for removing contamination from optical surfaces in space

    NASA Technical Reports Server (NTRS)

    Shannon, R. L.; Gillette, R. B.

    1973-01-01

    Research in developing an active cleaning technique for removing contaminants from optical surfaces in space is reported. In situ contamination/cleaning experiments were conducted on gold and platimum coated mirrors, which were contaminated by exposure to UV radiation in a 1,3, butadiene environment. Argon and oxygen plasma exposure cleaned the mirrors equally well. Silicone cleaning experiments were also conducted. Exposure of the contaminated mirrors to helium, oxygen, and hydrogen plasmas restored the reflectance at the shorter wavelengths and degraded it at the longer wavelengths.

  6. The 1992 catalog of space science and applications education programs and activities

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This catalog provides information on current, ongoing and pilot programs conducted at precollege through postdoctoral levels which are primarily funded or managed by the Office of Space Science Applications (OSSA). The directory of programs section includes teacher and faculty preparation and enhancement, student enrichment opportunities, student research opportunities, postdoctoral and advanced research opportunities, initiatives to strengthen educational institution involvement in research and initiatives to strengthen research community involvement in education. The Educational Products appendices include tabular data of OSSA activities, NASA Spacelink, NASA education satellites videoconferences, the Teacher Resource Center Network, and a form for requesting further information.

  7. Doppler and range determination for deep space vehicles using active optical transponders.

    PubMed

    Kinman, P W; Gagliardi, R M

    1988-11-01

    This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated. PMID:20539597

  8. A nonventing cooling system for space environment extravehicular activity, using radiation and regenerable thermal storage

    NASA Technical Reports Server (NTRS)

    Bayes, Stephen A.; Trevino, Luis A.; Dinsmore, Craig E.

    1988-01-01

    This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for extravehicular activity space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

  9. Space-by-time decomposition for single-trial decoding of M/EEG activity.

    PubMed

    Delis, Ioannis; Onken, Arno; Schyns, Philippe G; Panzeri, Stefano; Philiastides, Marios G

    2016-06-01

    We develop a novel methodology for the single-trial analysis of multichannel time-varying neuroimaging signals. We introduce the space-by-time M/EEG decomposition, based on Non-negative Matrix Factorization (NMF), which describes single-trial M/EEG signals using a set of non-negative spatial and temporal components that are linearly combined with signed scalar activation coefficients. We illustrate the effectiveness of the proposed approach on an EEG dataset recorded during the performance of a visual categorization task. Our method extracts three temporal and two spatial functional components achieving a compact yet full representation of the underlying structure, which validates and summarizes succinctly results from previous studies. Furthermore, we introduce a decoding analysis that allows determining the distinct functional role of each component and relating them to experimental conditions and task parameters. In particular, we demonstrate that the presented stimulus and the task difficulty of each trial can be reliably decoded using specific combinations of components from the identified space-by-time representation. When comparing with a sliding-window linear discriminant algorithm, we show that our approach yields more robust decoding performance across participants. Overall, our findings suggest that the proposed space-by-time decomposition is a meaningful low-dimensional representation that carries the relevant information of single-trial M/EEG signals. PMID:27033682

  10. In-flight aberrations corrections for large space telescopes using active optics

    NASA Astrophysics Data System (ADS)

    Laslandes, M.; Ferrari, M.; Hugot, E.; Lemaitre, G.

    2010-07-01

    The need for both high quality images and light structures is a constant concern in the conception of space telescopes. The goal here is to determine how an active optics system could be embarked on a satellite in order to correct the wave front deformations of the optical train. The optical aberrations appearing in a space environment are due to mirrors' deformations, with three main origins: the thermal variations, the weightlessness in space with respect to the Assemblage, Integration and Testing (AIT) conditions on ground and the use of large weightlighted primary mirrors. We are developing a model of deformable mirror as minimalist as possible, especially in term of number of actuators, which is able to correct the first Zernike polynomials in the specified range of amplitude and precision. Flight constraints as weight, volume and power consumption have to be considered. Firstly, such a system is designed according to the equations from the elasticity theory: we determine the geometrical and mechanical characteristics of the mirror, the location of the forces to be applied and the way to apply them. The concept is validated with a Finite Element Analysis (FEA), allowing optimizing the system by taking into account parameters absent from the theory. At the end of the program the mirror will be realized and characterized in a representative optical configuration.

  11. SPACeMAN -a Satellite to Actively Reduce Sub-Centimeter Debris

    NASA Astrophysics Data System (ADS)

    Knirsch, Uli

    In-orbit fragmentation events, whether accidental or intentional, are bound to increase the population of space debris. "Critical debris" ranging between 1 and 10mm are numerous and can be lethal to both satellites and inhabited structures. This in turn creates further debris, potentially leading to a chain reaction ("Kessler syndrome"). In first approximation, collecting sub-centimeter debris appears impractical since rendezvous maneuvers are prohibitively expensive in terms of delta v and hardware complexity. One possible solution is to fly a spacecraft with a small constant vertical thrust. As a result, it will move somewhat faster than other, passive objects in its orbit -such as space debris. This "non-Keplerian orbit" thus creates a small chance of accidental collision. The sPACeMAN is designed to withstand impacts, capturing the debris. Since the probability of capture is low, some active control, particularly of the vertical thrust, can be instituted. The sPACeMAN concept was developed to reduce the population of NaK droplets in critical orbits. However, it can be extended to other debris as well. Since its effectiveness is greatest in areas of relatively high population densities of space debris, it would be best suited for quick responses, such as after a fragmentation event.

  12. Active correction of aperture discontinuities (ACAD) for space telescope pupils: a parametic analysis

    NASA Astrophysics Data System (ADS)

    Mazoyer, Johan; Pueyo, Laurent; Norman, Colin; N'Diaye, Mamadou; Mawet, Dimitri; Soummer, Rémi; Perrin, Marshall; Choquet, Élodie; Carlotti, Alexis

    2015-09-01

    As the performance of coronagraphs improves, the achievable contrast is more and more dependent of the shape of the pupil. The future generation of space and ground based coronagraphic instruments will have to achieve high contrast levels on on-axis and/or segmented telescopes. To correct for the high amplitude aberrations introduced by secondary mirror structures and segmentation of the primary mirror, we explore a two deformable mirror (DM) method. The major difficulty of several DM methods is the non-linear relation linking actuator strokes to the point spread function in the coronagraph focal plane. The Active Compensation of Aperture Discontinuities (ACAD) method is achieving this minimization by solving a non linear differential Monge Ampere equation. Once this open loop method have reached the minimum, a close-loop stroke minimization method can be applied to correct for phase and amplitude aberrations to achieve the ultimate contrast. In this paper, I describe the results of the parametric analysis that that I have undertaken on this method. After recalling the principle of the method, I will described the explored parameter space (deformable mirror set-up, shape of the pupil, bandwidth, coronagraph designs). I will precisely described the way I simulated the Vortex coronagraph for this numerical simulation. Finally I will present the preliminary results of this parametric analysis for space telescope pupils only.

  13. State of Art in space weather observational activities and data management in Europe

    NASA Astrophysics Data System (ADS)

    Stanislawska, Iwona

    One of the primary scientific and technical goals of space weather is to produce data in order to investigate the Sun impact on the Earth and its environment. Studies based on data mining philosophy yield increase the knowledge of space weather physical properties, modelling capabilities and gain applications of various procedures in space weather monitoring and forecasting. Exchanging tailored individually and/or jointly data between different entities, storing of the databases and making data accessible for the users is the most important task undertaken by investigators. National activities spread over Europe is currently consolidated pursuant to the terms of effectiveness and individual contributions embedded in joint integrated efforts. The role of COST 724 Action in animation of such a movement is essential. The paper focuses on the analysis of the European availability in the Internet near-real time and historical collections of the European ground based and satellite observations, operational indices and parameters. A detailed description of data delivered is included. The structure of the content is supplied according to the following selection: (1) observations, raw and/or corrected, updated data, (2) resolution, availability of real-time and historical data, (3) products, as the results of models and theory including (a) maps, forecasts and alerts, (b) resolution, availability of real-time and historical data, (4) platforms to deliver data. Characterization of the networking of stations, observatories and space related monitoring systems of data collections is integrated part of the paper. According to these provisions operational systems developed for these purposes is presented and analysed. It concerns measurements, observations and parameters from the theory and models referred to local, regional collections, European and worldwide networks. Techniques used by these organizations to generate the digital content are identified. As the reference pan

  14. Human muscle sympathetic nerve activity and plasma noradrenaline kinetics in space

    NASA Technical Reports Server (NTRS)

    Ertl, Andrew C.; Diedrich, Andre; Biaggioni, Italo; Levine, Benjamin D.; Robertson, Rose Marie; Cox, James F.; Zuckerman, Julie H.; Pawelczyk, James A.; Ray, Chester A.; Buckey, Jay C Jr; Lane, Lynda D.; Shiavi, Richard; Gaffney, F. Andrew; Costa, Fernando; Holt, Carol; Blomqvist, C. Gunnar; Eckberg, Dwain L.; Baisch, Friedhelm J.; Robertson, David

    2002-01-01

    Astronauts returning from space have reduced red blood cell masses, hypovolaemia and orthostatic intolerance, marked by greater cardio-acceleration during standing than before spaceflight, and in some, orthostatic hypotension and presyncope. Adaptation of the sympathetic nervous system occurring during spaceflight may be responsible for these postflight alterations. We tested the hypotheses that exposure to microgravity reduces sympathetic neural outflow and impairs sympathetic neural responses to orthostatic stress. We measured heart rate, photoplethysmographic finger arterial pressure, peroneal nerve muscle sympathetic activity and plasma noradrenaline spillover and clearance, in male astronauts before, during (flight day 12 or 13) and after the 16 day Neurolab space shuttle mission. Measurements were made during supine rest and orthostatic stress, as simulated on Earth and in space by 7 min periods of 15 and 30 mmHg lower body suction. Mean (+/- S.E.M.) heart rates before lower body suction were similar pre-flight and in flight. Heart rate responses to -30 mmHg were greater in flight (from 56 +/- 4 to 72 +/- 4 beats min(-1)) than pre-flight (from 56 +/- 4 at rest to 62 +/- 4 beats min(-1), P < 0.05). Noradrenaline spillover and clearance were increased from pre-flight levels during baseline periods and during lower body suction, both in flight (n = 3) and on post-flight days 1 or 2 (n = 5, P < 0.05). In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33 %) in the same three subjects in whom noradrenaline spillover and clearance were increased. The sympathetic response to 30 mmHg lower body suction was at pre-flight levels or higher in each subject (35 pre-flight vs. 40 bursts min(-1) in flight). No astronaut experienced presyncope during lower body suction in space (or during upright tilt following the Neurolab mission). We conclude that in space, baseline sympathetic neural outflow is increased moderately and sympathetic

  15. Human muscle sympathetic nerve activity and plasma noradrenaline kinetics in space

    PubMed Central

    Ertl, Andrew C; Diedrich, André; Biaggioni, Italo; Levine, Benjamin D; Robertson, Rose Marie; Cox, James F; Zuckerman, Julie H; Pawelczyk, James A; Ray, Chester A; Buckey, Jay C; Lane, Lynda D; Shiavi, Richard; Gaffney, F Andrew; Costa, Fernando; Holt, Carol; Blomqvist, C Gunnar; Eckberg, Dwain L; Baisch, Friedhelm J; Robertson, David

    2002-01-01

    Astronauts returning from space have reduced red blood cell masses, hypovolaemia and orthostatic intolerance, marked by greater cardio–acceleration during standing than before spaceflight, and in some, orthostatic hypotension and presyncope. Adaptation of the sympathetic nervous system occurring during spaceflight may be responsible for these postflight alterations. We tested the hypotheses that exposure to microgravity reduces sympathetic neural outflow and impairs sympathetic neural responses to orthostatic stress. We measured heart rate, photoplethysmographic finger arterial pressure, peroneal nerve muscle sympathetic activity and plasma noradrenaline spillover and clearance, in male astronauts before, during (flight day 12 or 13) and after the 16 day Neurolab space shuttle mission. Measurements were made during supine rest and orthostatic stress, as simulated on Earth and in space by 7 min periods of 15 and 30 mmHg lower body suction. Mean (± s.e.m.) heart rates before lower body suction were similar pre–flight and in flight. Heart rate responses to −30 mmHg were greater in flight (from 56 ± 4 to 72 ± 4 beats min−1) than pre–flight (from 56 ± 4 at rest to 62 ± 4 beats min−1, P < 0.05). Noradrenaline spillover and clearance were increased from pre–flight levels during baseline periods and during lower body suction, both in flight (n = 3) and on post–flight days 1 or 2 (n = 5, P < 0.05). In–flight baseline sympathetic nerve activity was increased above pre–flight levels (by 10–33 %) in the same three subjects in whom noradrenaline spillover and clearance were increased. The sympathetic response to 30 mmHg lower body suction was at pre–flight levels or higher in each subject (35 pre–flight vs. 40 bursts min−1 in flight). No astronaut experienced presyncope during lower body suction in space (or during upright tilt following the Neurolab mission). We conclude that in space, baseline sympathetic neural outflow is increased moderately

  16. Augmentation and Maximization of Per-Capita Call Active Space Through Chorusing in Anuran Amphibians

    NASA Astrophysics Data System (ADS)

    Fox, James Henderson

    It is poorly understood why anuran males form choruses. Although various reasons have been proposed, empirical support is lacking. This study proposed, developed, and evaluated the chorus active space (CAS) augmentation theory, which states that anuran choruses are formed and organized so as to augment and maximize per-capita CAS beyond that which could be achieved by an isolated male. This study involved three phases. First, computer models of hypothetical choruses indicated that CAS, as defined, is necessarily augmented for chorusing males. These models provided the necessary information from which optimal interindividual distances (IIDs), corresponding to maximal CASs, could be estimated differentially for linear and planar chorus configurations. The second phase examined Acris crepitans and Hyla cinerea choruses for optimal intermale spacing. A. crepitans, which utilizes mixed chorus geometries (either linear or planar, depending on available resources), cannot optimize IID within any observed pond-type breeding site; however, observed spacing would be optimal along a stream bank, where chorusing often occurs, for a chorus population of 61, approximately the minimum value at which CAS characteristics are stabile. H. cinerea males, which form only planar choruses, space orders of magnitude closer than optimal. Suboptimal spacing in this species is understandable, considering the would-be size of an optimally spaced chorus. In the final phase of this study, a database of CAS-related data was compiled mostly from published sources and was examined for variable relationships predicted on the basis of CAS augmentation theory. The findings suggest that very few planar geometry species may maximize CAS; whereas, a much larger number of mixed geometry species, perhaps as well as linear geometry species, may maximize CAS. These findings loosely agree with the field study findings and suggest that CAS augmentation theory applies to at least a subset of anuran species and

  17. Titin-based modulation of active tension and interfilament lattice spacing in skinned rat cardiac muscle.

    PubMed

    Fukuda, Norio; Wu, Yiming; Farman, Gerrie; Irving, Thomas C; Granzier, Henk

    2005-02-01

    The effect of titin-based passive tension on Ca2+ sensitivity of active tension and interfilament lattice spacing was studied in skinned rat ventricular trabeculae by measuring the sarcomere length (SL)-dependent change in Ca2+ sensitivity and performing small angle X-ray diffraction studies. To vary passive tension, preparations were treated with trypsin at a low concentration (0.31 mug/ml) for a short period (13 min) at 20 degrees C, that resulted in approximately 40% degradation of the I-band region of titin, with a minimal effect on A-band titin. We found that the effect of trypsin on titin-based passive tension was significantly more pronounced immediately after stretch than at steady state, 30 min after stretch (i.e., trypsin has a greater effect on viscosity than on elasticity of passive cardiac muscle). Ca2+ sensitivity was decreased by trypsin treatment at SL 2.25 microm, but not at SL 1.9 microm, resulting in marked attenuation of the SL-dependent increase in Ca2+ sensitivity. The SL-dependent change in Ca2+ sensitivity was significantly correlated with titin-based passive tension. Small-angle X-ray diffraction experiments revealed that the lattice spacing expands after trypsin treatment, especially at SL 2.25 microm, providing an inverse linear relationship between the lattice spacing and Ca2+ sensitivity. These results support the view that titin-based passive tension promotes actomyosin interaction and that the mechanism includes interfilament lattice spacing modulation. PMID:15688246

  18. Evaluation of Active Working Fluids for Brayton Cycles in Space Applications

    NASA Astrophysics Data System (ADS)

    Conklin, J. C.; Courville, G. E.; Scott, J. H.

    2004-02-01

    The main parameter of interest for space thermal power conversion to electricity is specific power, defined as the total electric power output per unit of system mass, rather than the cycle thermal efficiency. For a closed Brayton cycle, performance with two active working fluids, nitrogen tetroxide and aluminum chloride, is compared to that with an inert mixture of helium and xenon having a molecular mass of 40. A chemically active working fluid is defined here as a chemical compound that has a relatively high molecular weight at temperatures appropriate for the compressor inlet and dissociates to a lighter molecular weight fluid at typical turbine inlet temperatures. The active working fluids may have the advantage of a higher net turbomachinery work output and an advantageous enhancement of the heat transfer coefficient in the heat exchangers. The fundamental theory of the active working fluid concept is presented to demonstrate these potential advantages. Scoping calculations of the heat exchanger mass for a selected spacecraft application of 36.4 kW of electrical power output show that the nitrogen tetroxide active working fluid has an advantageous 7% to 30% lower mass-to-power ratio than that for the inert noble gas mixture, depending on the allowable turbine inlet temperature. The calculations for the aluminum chloride system suggest only a slight improvement in performance relative to the inert noble gas mixture.

  19. A novel gene, MdSSK1, as a component of the SCF complex rather than MdSBP1 can mediate the ubiquitination of S-RNase in apple

    PubMed Central

    Yuan, Hui; Meng, Dong; Gu, Zhaoyu; Li, Wei; Wang, Aide; Yang, Qing; Zhu, Yuandi; Li, Tianzhong

    2014-01-01

    As a core factor in S-RNase-based gametophytic self-incompatibility (GSI), the SCF (SKP1–Cullin1–F-box-Rbx1) complex (including pollen determinant SLF, S-locus-F-box) functions as an E3 ubiquitin ligase on non-self S-RNase. The SCF complex is formed by SKP1 bridging between SLF, CUL1, and Rbx1; however, it is not known whether an SCF complex lacking SKP1 can mediate the ubiquitination of S-RNase. Three SKP1-like genes from pollen were cloned based on the structural features of the SLF-interacting-SKP1-like (SSK) gene and the ‘Golden Delicious’ apple genome. These genes have a motif of five amino acids following the standard ‘WAFE’ at the C terminal and, in addition, contain eight sheets and two helices. All three genes were expressed exclusively in pollen. In the yeast two-hybrid and pull-down assays only one was found to interact with MdSFBB and MdCUL1, suggesting it is the SLF-interacting SKP1-like gene in apple which was named MdSSK1. In vitro experiments using MdSSK1, S2-MdSFBB1 (S2-Malus domestica S-locus-F-box brother) and MdCUL1 proteins incubated with S 2-RNase and ubiquitin revealed that the SCF complex ubiquitinylates S-RNase in vitro, while MdSBP1 (Malus domestica S-RNase binding protein 1) could not functionally replace MdSSK1 in the SCF complex in ubiquitinylating S-RNase. According to the above experiments, MdSBP1 is probably the only factor responsible for recognition with S-RNase, while not a component of the SCF complex, and an SCF complex containing MdSSK1 is required for mediating the ubiquitination of S-RNase. PMID:24759884

  20. Retrospective space-time analysis methods to support West Nile virus surveillance activities.

    PubMed

    Mulatti, P; Mazzucato, M; Montarsi, F; Ciocchetta, S; Capelli, G; Bonfanti, L; Marangon, S

    2015-01-01

    The steep increase in human West Nile virus (WNV) infections in 2011-2012 in north-eastern Italy prompted a refinement of the surveillance plan. Data from the 2010-2012 surveillance activities on mosquitoes, equines, and humans were analysed through Bernoulli space-time scan statistics, to detect the presence of recurrent WNV infection hotspots. Linear models were fit to detect the possible relationships between WNV occurrence in humans and its activity in mosquitoes. Clusters were detected for all of the hosts, defining a limited area on which to focus surveillance and promptly identify WNV reactivation. Positive relationships were identified between WNV in humans and in mosquitoes; although it was not possible to define precise spatial and temporal scales at which entomological surveillance could predict the increasing risk of human infections. This stresses the necessity to improve entomological surveillance by increasing both the density of trapping sites and the frequency of captures. PMID:24641869