Accurate and efficient calculation of excitation energies with the active-space particle-particle random phase approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Du; Yang, Weitao

An efficient method for calculating excitation energies based on the particle-particle random phase approximation (ppRPA) is presented. Neglecting the contributions from the high-lying virtual states and the low-lying core states leads to the significantly smaller active-space ppRPA matrix while keeping the error to within 0.05 eV from the corresponding full ppRPA excitation energies. The resulting computational cost is significantly reduced and becomes less than the construction of the non-local Fock exchange potential matrix in the self-consistent-field (SCF) procedure. With only a modest number of active orbitals, the original ppRPA singlet-triplet (ST) gaps as well as the low-lying single and doublemore » excitation energies can be accurately reproduced at much reduced computational costs, up to 100 times faster than the iterative Davidson diagonalization of the original full ppRPA matrix. For high-lying Rydberg excitations where the Davidson algorithm fails, the computational savings of active-space ppRPA with respect to the direct diagonalization is even more dramatic. The virtues of the underlying full ppRPA combined with the significantly lower computational cost of the active-space approach will significantly expand the applicability of the ppRPA method to calculate excitation energies at a cost of O(K^{4}), with a prefactor much smaller than a single SCF Hartree-Fock (HF)/hybrid functional calculation, thus opening up new possibilities for the quantum mechanical study of excited state electronic structure of large systems.« less

Accurate and efficient calculation of excitation energies with the active-space particle-particle random phase approximation

DOE PAGES

Zhang, Du; Yang, Weitao

2016-10-13

An efficient method for calculating excitation energies based on the particle-particle random phase approximation (ppRPA) is presented. Neglecting the contributions from the high-lying virtual states and the low-lying core states leads to the significantly smaller active-space ppRPA matrix while keeping the error to within 0.05 eV from the corresponding full ppRPA excitation energies. The resulting computational cost is significantly reduced and becomes less than the construction of the non-local Fock exchange potential matrix in the self-consistent-field (SCF) procedure. With only a modest number of active orbitals, the original ppRPA singlet-triplet (ST) gaps as well as the low-lying single and doublemore » excitation energies can be accurately reproduced at much reduced computational costs, up to 100 times faster than the iterative Davidson diagonalization of the original full ppRPA matrix. For high-lying Rydberg excitations where the Davidson algorithm fails, the computational savings of active-space ppRPA with respect to the direct diagonalization is even more dramatic. The virtues of the underlying full ppRPA combined with the significantly lower computational cost of the active-space approach will significantly expand the applicability of the ppRPA method to calculate excitation energies at a cost of O(K^{4}), with a prefactor much smaller than a single SCF Hartree-Fock (HF)/hybrid functional calculation, thus opening up new possibilities for the quantum mechanical study of excited state electronic structure of large systems.« less

Optical fiber curvature sensor based on MMF-SCF-MMF structure

NASA Astrophysics Data System (ADS)

Wang, Qi; Liu, Yu

2018-07-01

A sensitive curvature sensor based on MMF-SCF-MMF (MMF: multimode fiber; SCF: seven core fiber) structure is proposed. The multimode fiber (MMF) are used to improve the light coupling efficiency between the input singlemode fiber (SMF) and the seven-core fiber (SCF), and the seven-core fiber is used as the main element for curvature measurement. Experimental results show that the best curvature sensitivity reaches 41.46453 nm/m-1 in the range of 0.094 m-1-0.567 m-1. The temperature sensitivity is up to 59.02 pm/°C in the range of 20 °C-55 °C. The optical curvature sensors are widely used for buildings structure health monitoring and mechanical engineering due to the advantages of compact structure, anti-electromagnetic interference, and low cost.

Systematic Expansion of Active Spaces beyond the CASSCF Limit: A GASSCF/SplitGAS Benchmark Study.

PubMed

Vogiatzis, Konstantinos D; Li Manni, Giovanni; Stoneburner, Samuel J; Ma, Dongxia; Gagliardi, Laura

2015-07-14

The applicability and accuracy of the generalized active space self-consistent field, (GASSCF), and (SplitGAS) methods are presented. The GASSCF method enables the exploration of larger active spaces than with the conventional complete active space SCF, (CASSCF), by fragmentation of a large space into subspaces and by controlling the interspace excitations. In the SplitGAS method, the GAS configuration interaction, CI, expansion is further partitioned in two parts: the principal, which includes the most important configuration state functions, and an extended, containing less relevant but not negligible ones. An effective Hamiltonian is then generated, with the extended part acting as a perturbation to the principal space. Excitation energies of ozone, furan, pyrrole, nickel dioxide, and copper tetrachloride dianion are reported. Various partitioning schemes of the GASSCF and SplitGAS CI expansions are considered and compared with the complete active space followed by second-order perturbation theory, (CASPT2), and multireference CI method, (MRCI), or available experimental data. General guidelines for the optimum applicability of these methods are discussed together with their current limitations.

Role of SKP1-CUL1-F-Box-Protein (SCF) E3 Ubiquitin Ligases in Skin Cancer

PubMed Central

Xie, Chuan-Ming; Wei, Wenyi; Sun, Yi

2013-01-01

Many biological processes such as cell proliferation, differentiation, and cell death depend precisely on the timely synthesis and degradation of key regulatory proteins. While protein synthesis can be regulated at multiple levels, protein degradation is mainly controlled by the ubiquitin—proteasome system (UPS), which consists of two distinct steps: (1) ubiquitylation of targeted protein by E1 ubiquitin-activating enzyme, E2 ubiquitin-conjugating enzyme and E3 ubiquitin ligase, and (2) subsequent degradation by the 26S proteasome. Among all E3 ubiquitin ligases, the SCF (SKP1-CUL1-F-box protein) E3 ligases are the largest family and are responsible for the turnover of many key regulatory proteins. Aberrant regulation of SCF E3 ligases is associated with various human diseases, such as cancers, including skin cancer. In this review, we provide a comprehensive overview of all currently published data to define a promoting role of SCF E3 ligases in the development of skin cancer. The future directions in this area of research are also discussed with an ultimate goal to develop small molecule inhibitors of SCF E3 ligases as a novel approach for the treatment of human skin cancer. Furthermore, altered components or substrates of SCF E3 ligases may also be developed as the biomarkers for early diagnosis or predicting prognosis. PMID:23522382

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. Copyright © 2013 Elsevier Inc. All rights reserved.

Bone marrow adipocytes promote the regeneration of stem cells and hematopoiesis by secreting SCF

PubMed Central

Zhou, Bo O.; Yu, Hua; Yue, Rui; Zhao, Zhiyu; Rios, Jonathan J.; Naveiras, Olaia; Morrison, Sean J.

2017-01-01

Endothelial cells and Leptin Receptor+ (LepR+) stromal cells are critical sources of haematopoietic stem cell (HSC) niche factors, including Stem Cell Factor (SCF), in bone marrow. After irradiation or chemotherapy, these cells are depleted while adipocytes become abundant. We discovered that bone marrow adipocytes synthesize SCF. They arise from Adipoq-Cre/ER+ progenitors, which represent ~5% of LepR+ cells, and proliferate after irradiation. Scf deletion using Adipoq-Cre/ER inhibited hematopoietic regeneration after irradiation or 5-fluorouracil treatment, depleting HSCs and reducing mouse survival. Scf from LepR+ cells, but not endothelial, hematopoietic, or osteoblastic cells, also promoted regeneration. In non-irradiated mice, Scf deletion using Adipoq-Cre/ER did not affect HSC frequency in long bones, which have few adipocytes, but depleted HSCs in tail vertebrae, which have abundant adipocytes. A-ZIP/F1 ‘fatless” mice exhibited delayed hematopoietic regeneration in long bones but not in tail vertebrae, where adipocytes inhibited vascularization. Adipocytes are a niche component that promotes hematopoietic regeneration. PMID:28714970

MLL-ENL cooperates with SCF to transform primary avian multipotent cells.

PubMed

Schulte, Cathleen E; von Lindern, Marieke; Steinlein, Peter; Beug, Hartmut; Wiedemann, Leanne M

2002-08-15

The MLL gene is targeted by chromosomal translocations, which give rise to heterologous MLL fusion proteins and are associated with distinct types of acute lymphoid and myeloid leukaemia. To determine how MLL fusion proteins alter the proliferation and/or differentiation of primary haematopoietic progenitors, we introduced the MLL-AF9 and MLL-ENL fusion proteins into primary chicken bone marrow cells. Both fusion proteins caused the sustained outgrowth of immature haematopoietic cells, which was strictly dependent on stem cell factor (SCF). The renewing cells have a long in vitro lifespan exceeding the Hayflick limit of avian cells. Analysis of clonal cultures identified the renewing cells as immature, multipotent progenitors, expressing erythroid, myeloid, lymphoid and stem cell surface markers. Employing a two-step commitment/differentiation protocol involving the controlled withdrawal of SCF, the MLL-ENL-transformed progenitors could be induced to terminal erythroid or myeloid differentiation. Finally, in cooperation with the weakly leukaemogenic receptor tyrosine kinase v-Sea, the MLL-ENL fusion protein gave rise to multilineage leukaemia in chicks, suggesting that other activated, receptor tyrosine kinases can substitute for ligand-activated c-Kit in vivo.

Skp1: Implications in cancer and SCF-oriented anti-cancer drug discovery.

PubMed

Hussain, Muzammal; Lu, Yongzhi; Liu, Yong-Qiang; Su, Kai; Zhang, Jiancun; Liu, Jinsong; Zhou, Guang-Biao

2016-09-01

In the last decade, the ubiquitin proteasome system (UPS), in general, and E3 ubiquitin ligases, in particular, have emerged as valid drug targets for the development of novel anti-cancer therapeutics. Cullin RING Ligases (CRLs), which can be classified into eight groups (CRL1-8) and comprise approximately 200 members, represent the largest family of E3 ubiquitin ligases which facilitate the ubiquitination-derived proteasomal degradation of a myriad of functionally and structurally diverse substrates. S phase kinase-associated protein 1 (Skp1)-Cullin1-F-Box protein (SCF) complexes are the best characterized among CRLs, which play crucial roles in numerous cellular processes and physiological dysfunctions, such as in cancer biology. Currently, there is growing interest in developing SCF-targeting anti-cancer therapies for clinical application. Indeed, the research in this field has seen some progress in the form of cullin neddylation- and Skp2-inhibitors. However, it still remains an underdeveloped area and needs to design new strategies for developing improved form of therapy. In this review, we venture a novel strategy that rational pharmacological targeting of Skp1, a central regulator of SCF complexes, may provide a novel avenue for SCF-oriented anti-cancer therapy, expected: (i) to simultaneously address the critical roles that multiple SCF oncogenic complexes play in cancer biology, (ii) to selectively target cancer cells with minimal normal cell toxicity, and (iii) to offer multiple chemical series, via therapeutic interventions at the Skp1 binding interfaces in SCF complex, thereby maximizing chances of success for drug discovery. In addition, we also discuss the challenges that might be posed regarding rational pharmacological interventions against Skp1. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bone marrow adipocytes promote the regeneration of stem cells and haematopoiesis by secreting SCF.

PubMed

Zhou, Bo O; Yu, Hua; Yue, Rui; Zhao, Zhiyu; Rios, Jonathan J; Naveiras, Olaia; Morrison, Sean J

2017-08-01

Endothelial cells and leptin receptor + (LepR + ) stromal cells are critical sources of haematopoietic stem cell (HSC) niche factors, including stem cell factor (SCF), in bone marrow. After irradiation or chemotherapy, these cells are depleted while adipocytes become abundant. We discovered that bone marrow adipocytes synthesize SCF. They arise from Adipoq-Cre/ER + progenitors, which represent ∼5% of LepR + cells, and proliferate after irradiation. Scf deletion using Adipoq-Cre/ER inhibited haematopoietic regeneration after irradiation or 5-fluorouracil treatment, depleting HSCs and reducing mouse survival. Scf from LepR + cells, but not endothelial, haematopoietic or osteoblastic cells, also promoted regeneration. In non-irradiated mice, Scf deletion using Adipoq-Cre/ER did not affect HSC frequency in long bones, which have few adipocytes, but depleted HSCs in tail vertebrae, which have abundant adipocytes. A-ZIP/F1 'fatless' mice exhibited delayed haematopoietic regeneration in long bones but not in tail vertebrae, where adipocytes inhibited vascularization. Adipocytes are a niche component that promotes haematopoietic regeneration.

σ-SCF: A direct energy-targeting method to mean-field excited states

NASA Astrophysics Data System (ADS)

Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D.; Van Voorhis, Troy

2017-12-01

The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry—a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states—ground or excited—are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H2, HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

σ-SCF: A direct energy-targeting method to mean-field excited states.

PubMed

Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D; Van Voorhis, Troy

2017-12-07

The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry-a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states-ground or excited-are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H 2 , HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

GM-CSF Inhibits c-Kit and SCF Expression by Bone Marrow-Derived Dendritic Cells

PubMed Central

Barroeta Seijas, Amairelys Belen; Simonetti, Sonia; Vitale, Sara; Runci, Daniele; Quinci, Angela Caterina; Soriani, Alessandra; Criscuoli, Mattia; Filippi, Irene; Naldini, Antonella; Sacchetti, Federico Maria; Tarantino, Umberto; Oliva, Francesco; Piccirilli, Eleonora; Santoni, Angela; Di Rosa, Francesca

2017-01-01

Stem cell factor (SCF), the ligand of c-kit, is a key cytokine for hematopoiesis. Hematopoietic precursors express c-kit, whereas differentiated cells of hematopoietic lineage are negative for this receptor, with the exception of NK cells, mast cells, and a few others. While it has long been recognized that dendritic cells (DCs) can express c-kit, several questions remain concerning the SCF/c-kit axis in DCs. This is particularly relevant for DCs found in those organs wherein SCF is highly expressed, including the bone marrow (BM). We characterized c-kit expression by conventional DCs (cDCs) from BM and demonstrated a higher proportion of c-kit+ cells among type 1 cDC subsets (cDC1s) than type 2 cDC subsets (cDC2s) in both humans and mice, whereas similar levels of c-kit expression were observed in cDC1s and cDC2s from mouse spleen. To further study c-kit regulation, DCs were generated with granulocyte-macrophage colony-stimulating factor (GM-CSF) from mouse BM, a widely used protocol. CD11c+ cells were purified from pooled non-adherent and slightly adherent cells collected after 7 days of culture, thus obtaining highly purified BM-derived DCs (BMdDCs). BMdDCs contained a small fraction of c-kit+ cells, and by replating them for 2 days with GM-CSF, we obtained a homogeneous population of c-kit+ CD40hi MHCIIhi cells. Not only did BMdDCs express c-kit but they also produced SCF, and both were striking upregulated if GM-CSF was omitted after replating. Furthermore, a small but significant reduction in BMdDC survival was observed upon SCF silencing. Incubation of BMdDCs with SCF did not modulate antigen presentation ability of these cells, nor it did regulate their membrane expression of the chemokine receptor CXCR4. We conclude that the SCF/c-kit-mediated prosurvival circuit may have been overlooked because of the prominent use of GM-CSF in DC cultures in vitro, including those human DC cultures destined for the clinics. We speculate that DCs more prominently rely

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

DOE PAGES

Gorelik, Maryna; Orlicky, Stephen; Sartori, Maria A.; ...

2016-03-14

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.more » 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.« less

Hierarchy of stroma-derived factors in supporting growth of stroma-dependent hemopoietic cells: membrane-bound SCF is sufficient to confer stroma competence to epithelial cells.

PubMed

Friel, Jutta; Itoh, Katsuhiko; Bergholz, Ulla; Jücker, Manfred; Stocking, Carol; Harrison, Paul; Ostertag, Wolfram

2002-03-01

Hemopoiesis takes place in a microenvironment where hemopoietic cells are closely associated with stroma by various interactions. Stroma coregulates the proliferation and differentiation of hemopoietic cells. Stroma-hemopoietic-cell contact can be supported by locally produced membrane associated growth factors. The stroma derived growth factor, stem cell factor (SCF) is important in hemopoiesis. We examined the different biological interactions of membrane bound and soluble SCF with human hemopoietic cells expressing the SCF receptor, c-kit. To analyze the function of the SCF isoforms in inducing the proliferation of hemopoietic TF1 or Cord blood (CB) CD34+ cells we used stroma cell lines that differ in their presentation of no SCF, membrane SCF, or soluble SCF. We established a new coculture system using an epithelial cell line that excludes potential interfering effects with other known stroma encoded hemopoietic growth factors. We show that soluble SCF, in absence of membrane-bound SCF, inhibits long term clonal growth of primary or established CD34+ hemopoietic cells, whereas membrane-inserted SCF "dominantly" induces long term proliferation of these cells. We demonstrate a hierarchy of these SCF isoforms in the interaction of stroma with hemopoietic TF1 cells. Membrane-bound SCF is "dominant" over soluble SCF, whereas soluble SCF acts epistatically in interacting with hemopoietic cells compared with other stroma derived factors present in SCF deficient stroma. A hierarchy of stroma cell lines can be arranged according to their presentation of membrane SCF or soluble SCF. In our model system, membrane-bound SCF expression is sufficient to confer stroma properties to an epithelial cell line but soluble SCF does not.

AmeriFlux US-SCf Southern California Climate Gradient - Oak/Pine Forest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Mike

This is the AmeriFlux version of the carbon flux data for the site US-SCf Southern California Climate Gradient - Oak/Pine Forest. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of six Southern California Climate Gradient flux towers operated along an elevation gradient (sites are US-SCg, US-SCs, US-SCf, US-SCw, US-SCc, US-SCd). This site is a mixed oak/pine forest. The site experiences episodic severe drought and mortality, and has also experienced occasional logging and wildfire. Drought and mortality was especially severe in the early 2000s.

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

Mudhasani, Rajini; Tran, Julie P; Retterer, Cary; Kota, Krishna P; Whitehouse, Chris A; Bavari, Sina

2016-02-01

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 SCF(FBXW11) E3 ligase. We further show that disrupting the assembly of the SCF(FBXW11-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 SCF(FBXW11-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 SCF(FBXW11) 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.

SCF/C-Kit/JNK/AP-1 Signaling Pathway Promotes Claudin-3 Expression in Colonic Epithelium and Colorectal Carcinoma.

PubMed

Wang, Yaxi; Sun, Tingyi; Sun, Haimei; Yang, Shu; Li, Dandan; Zhou, Deshan

2017-04-06

Claudin-3 is a major protein of tight junctions (TJs) in the intestinal epithelium and is critical for maintaining cell-cell adhesion, barrier function, and epithelium polarity. Recent studies have shown high claudin-3 levels in several solid tumors, but the regulation mechanism of claudin-3 expression remains poorly understood. In the present study, colorectal cancer (CRC) tissues, HT-29 and DLD-1 CRC cell lines, CRC murine model (C57BL/6 mice) and c-kit loss-of-function mutant mice were used. We demonstrated that elevated claudin-3 levels were positively correlated with highly expressed c-kit in CRC tissues based upon analysis of protein expression. In vitro, claudin-3 expression was clearly increased in CRC cells by overexpressed c-kit or stimulated by exogenous recombinant human stem cell factor (rhSCF), while significantly decreased by the treatment with c-kit or c-Jun N-terminal kinase (JNK) inhibitors. Chromatin immunoprecipitation (ChIP) and luciferase reporter assay showed that SCF/c-kit signaling significantly promoted activator protein-1 (AP-1) binding with CLDN-3 promoter and enhanced its transcription activity. Furthermore, decreased expression of claudin-3 was obtained in the colonic epithelium from the c-Kit loss-of-function mutant mice. In conclusion, SCF/c-kit-JNK/AP-1 signaling pathway significantly promoted claudin-3 expression in colonic epithelium and CRC, which could contribute to epithelial barrier function maintenance and to CRC development.

σ -SCF: A Direct Energy-targeting Method To Mean-field Excited States

NASA Astrophysics Data System (ADS)

Ye, Hongzhou; Welborn, Matthew; Ricke, Nathan; van Voorhis, Troy

The mean-field solutions of electronic excited states are much less accessible than ground state (e.g. Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF, tend to fall into the lowest solution consistent with a given symmetry - a problem known as ``variational collapse''. In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states - ground or excited - are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H2, HF). This work was funded by a Grant from NSF (CHE-1464804).

The AtRbx1 protein is part of plant SCF complexes, and its down-regulation causes severe growth and developmental defects.

PubMed

Lechner, Esther; Xie, Daoxin; Grava, Sandrine; Pigaglio, Emmanuelle; Planchais, Severine; Murray, James A H; Parmentier, Yves; Mutterer, Jerome; Dubreucq, Bertrand; Shen, Wen-Hui; Genschik, Pascal

2002-12-20

Recently in yeast and animal cells, one particular class of ubiquitin ligase (E3), called the SCF, was demonstrated to regulate diverse processes including cell cycle and development. In plants SCF-dependent proteolysis is also involved in different developmental and hormonal regulations. To further investigate the function of SCF, we characterized at the molecular level the Arabidopsis RING-H2 finger protein AtRbx1. We demonstrated that the plant gene is able to functionally complement a yeast knockout mutant strain and showed that AtRbx1 protein interacts physically with at least two members of the Arabidopsis cullin family (AtCul1 and AtCul4). AtRbx1 also associates with AtCul1 and the Arabidopsis SKP1-related proteins in planta, indicating that it is part of plant SCF complexes. AtRbx1 mRNAs accumulate in various tissues of the plant, but at higher levels in tissues containing actively dividing cells. Finally to study the function of the gene in planta, we either overexpressed AtRbx1 or reduced its expression by a dsRNA strategy. Down-regulation of AtRbx1 impaired seedling growth and development, indicating that the gene is essential in plants. Furthermore, the AtRbx1-silenced plants showed a reduced level of AtCul1 protein, but accumulated higher level of cyclin D3.

New insights into the negative thermal expansion: Direct experimental evidence for the “guitar-string” effect in cubic ScF 3

DOE PAGES

Hu, Lei; Chen, Jun; Sanson, Andrea; ...

2016-06-23

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 ScF 3, one of the most outstanding materials with NTE. The local dynamics of ScF 3 has been investigated by a combined analysis of synchrotron-based X-ray total scattering, ex-tended 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 be-tween Sc-F nearest-neighbors are highly elongated in the directionmore » 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. Here, these results are the 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.« less

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

Localized Symmetry Breaking for Tuning Thermal Expansion in ScF 3 Nanoscale Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Lei; Qin, Feiyu; Sanson, Andrea

The local symmetry, beyond the averaged crystallographic structure, tends to bring unu-sual performances. Negative thermal expansion is a peculiar physical property of solids. Here, we report the delicate design of the localized symmetry breaking to achieve the controllable thermal expansion in ScF3 nano-scale frameworks. Intriguingly, an isotropic zero thermal expansion is concurrently engi-neered by localized symmetry breaking, with a remarkably low coefficient of thermal expansion of about +4.0×10-8/K up to 675K. This mechanism is investigated by the joint analysis of atomic pair dis-tribution function of synchrotron X-ray total scattering and extended X-ray absorption fine structure spectra. A localized rhombohedral distortionmore » presumably plays a critical role in stiffening ScF3 nano-scale frameworks and concomitantly suppressing transverse thermal vibrations of fluorine atoms. This physical scenario is also theoretically corroborated by the extinction of phonon modes with negative Grüneisen parameters in the rhombohedral ScF3. The present work opens an untraditional chemical modification to achieve controllable thermal expansion by breaking local symmetries of materials.« less

Non-linear eigensolver-based alternative to traditional SCF methods

NASA Astrophysics Data System (ADS)

Gavin, Brendan; Polizzi, Eric

2013-03-01

The self-consistent iterative procedure in Density Functional Theory calculations is revisited using a new, highly efficient and robust algorithm for solving the non-linear eigenvector problem (i.e. H(X)X = EX;) of the Kohn-Sham equations. This new scheme is derived from a generalization of the FEAST eigenvalue algorithm, and provides a fundamental and practical numerical solution for addressing the non-linearity of the Hamiltonian with the occupied eigenvectors. In contrast to SCF techniques, the traditional outer iterations are replaced by subspace iterations that are intrinsic to the FEAST algorithm, while the non-linearity is handled at the level of a projected reduced system which is orders of magnitude smaller than the original one. Using a series of numerical examples, it will be shown that our approach can outperform the traditional SCF mixing techniques such as Pulay-DIIS by providing a high converge rate and by converging to the correct solution regardless of the choice of the initial guess. We also discuss a practical implementation of the technique that can be achieved effectively using the FEAST solver package. This research is supported by NSF under Grant #ECCS-0846457 and Intel Corporation.

A multireference perturbation method using non-orthogonal Hartree-Fock determinants for ground and excited states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yost, Shane R.; Kowalczyk, Tim; Van Voorhis, Troy, E-mail: tvan@mit.edu

2013-11-07

In this article we propose the ΔSCF(2) framework, a multireference strategy based on second-order perturbation theory, for ground and excited electronic states. Unlike the complete active space family of methods, ΔSCF(2) employs a set of self-consistent Hartree-Fock determinants, also known as ΔSCF states. Each ΔSCF electronic state is modified by a first-order correction from Møller-Plesset perturbation theory and used to construct a Hamiltonian in a configuration interactions like framework. We present formulas for the resulting matrix elements between nonorthogonal states that scale as N{sub occ}{sup 2}N{sub virt}{sup 3}. Unlike most active space methods, ΔSCF(2) treats the ground and excited statemore » determinants even-handedly. We apply ΔSCF(2) to the H{sub 2}, hydrogen fluoride, and H{sub 4} systems and show that the method provides accurate descriptions of ground- and excited-state potential energy surfaces with no single active space containing more than 10 ΔSCF states.« less

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

PubMed

Zhou, Weihua; Wei, Wenyi; Sun, Yi

2013-05-01

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.

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

Cheng, Mingrong; Zhi, Kangkang; Gao, Xiaoyan; He, Bing; Li, Yingchun; Han, Jiang; Zhang, Zhiping; Wu, Yan

2013-12-18

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. 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. 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. The recombinant expression plasmid inhibited liver cancer by a mechanism that involved activation of cell-mediated immunity and Rae-1 in liver cancer.

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

2015-07-02

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

A Phase-Space Approach to Collisionless Stellar Systems Using a Particle Method

NASA Astrophysics Data System (ADS)

Hozumi, Shunsuke

1997-10-01

A particle method for reproducing the phase space of collisionless stellar systems is described. The key idea originates in Liouville's theorem, which states that the distribution function (DF) at time t can be derived from tracing necessary orbits back to t = 0. To make this procedure feasible, a self-consistent field (SCF) method for solving Poisson's equation is adopted to compute the orbits of arbitrary stars. As an example, for the violent relaxation of a uniform density sphere, the phase-space evolution generated by the current method is compared to that obtained with a phase-space method for integrating the collisionless Boltzmann equation, on the assumption of spherical symmetry. Excellent agreement is found between the two methods if an optimal basis set for the SCF technique is chosen. Since this reproduction method requires only the functional form of initial DFs and does not require any assumptions to be made about the symmetry of the system, success in reproducing the phase-space evolution implies that there would be no need of directly solving the collisionless Boltzmann equation in order to access phase space even for systems without any special symmetries. The effects of basis sets used in SCF simulations on the reproduced phase space are also discussed.

Cadmium exposure in newborn rats ovary induces developmental disorders of primordial follicles and the differential expression of SCF/c-kit gene.

PubMed

Zhang, Wenchang; Wu, Tingting; Zhang, Chenyun; Luo, Lingfeng; Xie, Meimei; Huang, Huiling

2017-10-05

Since the 1990s, the rising problem that gonad reproductive toxicity on adult female after exposing to cadmium (Cd), an environmental endocrine disruptor, has attracted high attention at home and abroad,and was systematically studied. Our research focuses on a further problem is that early cadmium exposure (during birth to before puberty) impact on development and function of ovarian cells and its possible mechanism. Our research focuses on the changes of ovarian cells growth and development after the newborn rat ovaries with cadmium exposure in vitro, and different expression of ovarian cells development-related factors, SCF/c-kit and changes of their DNA methylation status. We obtained ovaries from 4-day-old SD rats and cultured them in DMEM/F12 mixed with α-MEM media in vitro. Different doses of cadmium were designed as control, 0.5, 5, 10 and 50μM, and then the constituent ratio of ovarian follicle and follicular oocytes diameter were observed with microscope after 4-h exposure. We found that the increased constituent ratio of original follicle and decreased diameter of all levels of follicular oocytes(compared with control, with statistically significant differences, P<0.01).After the measurement of expression of SCF/c-kit by qRT-PCR and Western Blotting, the mRNA and protein expression of SCF/c-kit in ovarian were both decreased. We further found that the increased constituent ratio of growth follicle and increased diameter of oocytes under the treatment of adding SCF in cell culture media. Finally, MALDI-TOF-MS method showed DNA-low methylation status of SCF/c-kit promoter region after Cd exposure. Overall, we concluded that the exposure of cadimium (5-50μM) on newborn rats ovaries could inhibit follicle development.SCF/c-kit system might mediate follicle development damage caused by cadmium, which is associated with DNA hypomethylation of SCF/c-kit promoter region may be worthy of further study. Copyright © 2017. Published by Elsevier B.V.

Ectromelia virus encodes a novel family of F-box proteins that interact with the SCF complex.

PubMed

van Buuren, Nick; Couturier, Brianne; Xiong, Yue; Barry, Michele

2008-10-01

Poxviruses are notorious for encoding multiple proteins that regulate cellular signaling pathways, including the ubiquitin-proteasome system. Bioinformatics indicated that ectromelia virus, the causative agent of lethal mousepox, encoded four proteins, EVM002, EVM005, EVM154, and EVM165, containing putative F-box domains. In contrast to cellular F-box proteins, the ectromelia virus proteins contain C-terminal F-box domains in conjunction with N-terminal ankyrin repeats, a combination that has not been previously reported for cellular proteins. These observations suggested that the ectromelia virus F-box proteins interact with SCF (Skp1, cullin-1, and F-box) ubiquitin ligases. We focused our studies on EVM005, since this protein had only one ortholog in cowpox virus. Using mass spectrometry, we identified cullin-1 as a binding partner for EVM005, and this interaction was confirmed by overexpression of hemagglutinin (HA)-cullin-1. During infection, Flag-EVM005 and HA-cullin-1 colocalized to distinct cellular bodies. Significantly, EVM005 coprecipitated with endogenous Skp1, cullin-1, and Roc1 and associated with conjugated ubiquitin, suggesting that EVM005 interacted with the components of a functional ubiquitin ligase. Interaction of EVM005 with cullin-1 and Skp1 was abolished upon deletion of the F-box, indicating that the F-box played a crucial role in interaction with the SCF complex. Additionally, EVM002 and EVM154 interacted with Skp1 and conjugated ubiquitin, suggesting that ectromelia virus encodes multiple F-box-containing proteins that regulate the SCF complex. Our results indicate that ectromelia virus has evolved multiple proteins that interact with the SCF complex.

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.

Creation of the new industry-standard space test of laser retroreflectors for the GNSS and LAGEOS

NASA Astrophysics Data System (ADS)

Dell'Agnello, S.; Delle Monache, G. O.; Currie, D. G.; Vittori, R.; Cantone, C.; Garattini, M.; Boni, A.; Martini, M.; Lops, C.; Intaglietta, N.; Tauraso, R.; Arnold, D. A.; Pearlman, M. R.; Bianco, G.; Zerbini, S.; Maiello, M.; Berardi, S.; Porcelli, L.; Alley, C. O.; McGarry, J. F.; Sciarretta, C.; Luceri, V.; Zagwodzki, T. W.

2011-03-01

We built a new experimental apparatus (the “Satellite/lunar laser ranging Characterization Facility”, SCF) and created a new test procedure (the SCF-Test) to characterize and model the detailed thermal behavior and the optical performance of cube corner laser retroreflectors in space for industrial and scientific applications. The primary goal of these innovative tools is to provide critical design and diagnostic capabilities for Satellites Laser Ranging (SLR) to Galileo and other GNSS (Global Navigation Satellite System) constellations. The capability will allow us to optimize the design of GNSS laser retroreflector payloads to maximize ranging efficiency, to improve signal-to-noise conditions in daylight and to provide pre-launch validation of retroreflector performance under laboratory-simulated space conditions. Implementation of new retroreflector designs being studied will help to improve GNSS orbits, which will then increase the accuracy, stability, and distribution of the International Terrestrial Reference Frame (ITRF), to provide better definition of the geocenter (origin) and the scale (length unit).Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of the SLR retroreflector payload under thermal conditions produced with a close-match solar simulator. The apparatus includes infrared cameras for non-invasive thermometry, thermal control and real-time movement of the payload to experimentally simulate satellite orientation on orbit with respect to both solar illumination and laser interrogation beams. These unique capabilities provide experimental validation of the space segment for SLR and Lunar Laser Ranging (LLR).We used the SCF facility and the SCF-Test to perform a comprehensive, non-invasive space characterization of older generation, back-coated retroreflectors of the GIOVE-A and -B (Galileo In-Orbit Validation Elements) and the GPS-35

Research into topology optimization and the FDM method for a space cracked membrane

NASA Astrophysics Data System (ADS)

Hu, Qingxi; Li, Wanyuan; Zhang, Haiguang; Liu, Dali; Peng, Fujun; Duan, Yongchao

2017-07-01

The problem that the space membranes are easily torn open is the main focus in this paper, and a bionic strengthening-ribs structure is proposed for a space membrane based on interdisciplinary strengths, such as topology optimization, composite materials, and rapid prototyping. The optimization method and modeling method of membranes with bionic strengthening-ribs was studied. The PEEK and SCF/PEEK composite material which are applied to the space environment are chosen, and FDM technology is used. Through topology optimization, bionic strengthening-ribs with good tensile and tear capacities were obtained. Cracked membranes, cracked membranes with PEEK strengthening-ribs and SCF/PEEK strengthening-ribs were tested and test data were obtained. An extension situation and tension fracture were compared for three cases. The experimental results showed that membranes with the bionic strengthening-ribs structure have better mechanical properties, and the strength of the membranes with PEEK and SCF/PEEK strengthening-ribs were raised, respectively, up to 266.9% and 185.9%. The strengthening-ribs structure greatly improves the capacity to halt membrane crack-growth, which has an important significance to avoid membrane tear, and to ensure the spacecraft orbital lifetime.

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

[4-t-butylphenyl]-N-(4-imidazol-1-yl phenyl)sulfonamide (ISCK03) inhibits SCF/c-kit signaling in 501mel human melanoma cells and abolishes melanin production in mice and brownish guinea pigs.

PubMed

Na, Yong Joo; Baek, Heung Su; Ahn, Soo Mi; Shin, Hyun Jung; Chang, Ih-Seop; Hwang, Jae Sung

2007-09-01

It is well known that c-kit is related to pigmentation as well as to the oncology target protein. The objective of this study was to discover a skin-whitening agent that regulates c-kit activity. We have developed a high-throughput screening system using recombinant human c-kit protein. Approximately 10,000 synthetic compounds were screened for their effect on c-kit activity. Phenyl-imidazole sulfonamide derivatives showed inhibitory activity on c-kit phosphorylation in vitro. The effects of one derivative, [4-t-butylphenyl]-N-(4-imidazol-1-yl phenyl)sulfonamide (ISCK03), on stem-cell factor (SCF)/c-kit cellular signaling in 501mel human melanoma cells were examined further. Pretreatment of 501mel cells with ISCK03 inhibited SCF-induced c-kit phosphorylation dose dependently. ISCK03 also inhibited p44/42 ERK mitogen-activated protein kinase (MAPK) phosphorylation, which is known to be involved in SCF/c-kit downstream signaling. However ISCK03 did not inhibit hepatocyte growth factor (HGF)-induced phosphorylation of p44/42 ERK proteins. To determine the in vivo potency of ISCK03, it was orally administered to depilated C57BL/6 mice. Interestingly, oral administration of ISCK03 induced the dose-dependent depigmentation of newly regrown hair, and this was reversed with cessation of ISCK03 treatment. Finally, to investigate whether the inhibitory effect of ISCK03 on SCF/c-kit signaling abolished UV-induced pigmentation, ISCK03 was applied to UV-induced pigmented spots on brownish guinea pig skin. The topical application of ISCK03 promoted the depigmentation of UV-induced hyperpigmented spots. Fontana-Masson staining analysis showed epidermal melanin was diminished in spots treated with ISCK03. These results indicate that phenyl-imidazole sulfonamide derivatives are potent c-kit inhibitors and might be used as skin-whitening agents.

SCF(KMD) controls cytokinin signaling by regulating the degradation of type-B response regulators.

PubMed

Kim, Hyo Jung; Chiang, Yi-Hsuan; Kieber, Joseph J; Schaller, G Eric

2013-06-11

Cytokinins are plant hormones that play critical roles in growth and development. In Arabidopsis, the transcriptional response to cytokinin is regulated by action of type-B Arabidopsis response regulators (ARRs). Although central elements in the cytokinin signal transduction pathway have been identified, mechanisms controlling output remain to be elucidated. Here we demonstrate that a family of F-box proteins, called the kiss me deadly (KMD) family, targets type-B ARR proteins for degradation. KMD proteins form an S-phase kinase-associated PROTEIN1 (SKP1)/Cullin/F-box protein (SCF) E3 ubiquitin ligase complex and directly interact with type-B ARR proteins. Loss-of-function KMD mutants stabilize type-B ARRs and exhibit an enhanced cytokinin response. In contrast, plants with elevated KMD expression destabilize type-B ARR proteins leading to cytokinin insensitivity. Our results support a model in which an SCF(KMD) complex negatively regulates cytokinin responses by controlling levels of a key family of transcription factors.

Mast cells and fibroblasts work in concert to aggravate pulmonary fibrosis: role of transmembrane SCF and the PAR-2/PKC-α/Raf-1/p44/42 signaling pathway.

PubMed

Wygrecka, Malgorzata; Dahal, Bhola K; Kosanovic, Djuro; Petersen, Frank; Taborski, Brigitte; von Gerlach, Susanne; Didiasova, Miroslava; Zakrzewicz, Dariusz; Preissner, Klaus T; Schermuly, Ralph T; Markart, Philipp

2013-06-01

Mast cell (MC) accumulation has been demonstrated in the lungs of idiopathic pulmonary fibrosis (IPF) patients. Mediators released from MCs may regulate tissue remodeling processes, thereby contributing to IPF pathogenesis. We investigated the role of MC-fibroblast interaction in the progression of lung fibrosis. Increased numbers of activated MCs, in close proximity to fibroblast foci and alveolar type II cells, were observed in IPF lungs. Correspondingly elevated tryptase levels were detected in IPF lung tissue samples. Coculture of human lung MCs with human lung fibroblasts (HLFs) induced MC activation, as evinced by tryptase release, and stimulated HLF proliferation; IPF HLFs exhibited a significantly higher growth rate, compared with control. Tryptase stimulated HLF growth in a PAR-2/PKC-α/Raf-1/p44/42-dependent manner and potentiated extracellular matrix production, but independent of PKC-α, Raf-1, and p44/42 activities. Proproliferative properties of tryptase were attenuated by knockdown or pharmacological inhibition of PAR-2, PKC-α, Raf-1, or p44/42. Expression of transmembrane SCF, but not soluble SCF, was elevated in IPF lung tissue and in fibroblasts isolated from IPF lungs. Coculture of IPF HLFs with MCs enhanced MC survival and proliferation. These effects were cell-contact dependent and could be inhibited by application of anti-SCF antibody or CD117 inhibitor. Thus, fibroblasts and MCs appear to work in concert to perpetuate fibrotic processes and so contribute to lung fibrosis progression. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

GeneSCF: a real-time based functional enrichment tool with support for multiple organisms.

PubMed

Subhash, Santhilal; Kanduri, Chandrasekhar

2016-09-13

High-throughput technologies such as ChIP-sequencing, RNA-sequencing, DNA sequencing and quantitative metabolomics generate a huge volume of data. Researchers often rely on functional enrichment tools to interpret the biological significance of the affected genes from these high-throughput studies. However, currently available functional enrichment tools need to be updated frequently to adapt to new entries from the functional database repositories. Hence there is a need for a simplified tool that can perform functional enrichment analysis by using updated information directly from the source databases such as KEGG, Reactome or Gene Ontology etc. In this study, we focused on designing a command-line tool called GeneSCF (Gene Set Clustering based on Functional annotations), that can predict the functionally relevant biological information for a set of genes in a real-time updated manner. It is designed to handle information from more than 4000 organisms from freely available prominent functional databases like KEGG, Reactome and Gene Ontology. We successfully employed our tool on two of published datasets to predict the biologically relevant functional information. The core features of this tool were tested on Linux machines without the need for installation of more dependencies. GeneSCF is more reliable compared to other enrichment tools because of its ability to use reference functional databases in real-time to perform enrichment analysis. It is an easy-to-integrate tool with other pipelines available for downstream analysis of high-throughput data. More importantly, GeneSCF can run multiple gene lists simultaneously on different organisms thereby saving time for the users. Since the tool is designed to be ready-to-use, there is no need for any complex compilation and installation procedures.

Protein kinase C-δ-mediated recycling of active KIT in colon cancer.

PubMed

Park, Misun; Kim, Won Kyu; Song, Meiying; Park, Minhee; Kim, Hyunki; Nam, Hye Jin; Baek, Sung Hee; Kim, Hoguen

2013-09-15

Abnormal signaling through receptor tyrosine kinase (RTK) moieties is important in tumorigenesis and drug targeting of colorectal cancers. Wild-type KIT (WT-KIT), a RTK that is activated upon binding with stem cell factor (SCF), is highly expressed in some colon cancers; however, little is known about the functional role of SCF-dependent KIT activation in colon cancer pathogenesis. We aimed to elucidate the conditions and roles of WT-KIT activation in colon cancer tumorigenesis. Colorectal cancers with KIT expression were characterized by immunoblotting and immunohistochemistry. The biologic alterations after KIT-SCF binding were analyzed with or without protein kinase C (PKC) activation. We found that WT-KIT was expressed in a subset of colon cancer cell lines and was activated by SCF, leading to activation of downstream AKT and extracellular signal-regulated kinase (ERK) signaling pathways. We also showed that KIT expression gradually decreased, after prolonged SCF stimulation, due to lysosomal degradation. Degradation of WT-KIT after SCF binding was significantly rescued when PKC was activated. We also showed the involvement of activated PKC-δ in the recycling of WT-KIT. We further showed that a subset of colorectal cancers exhibit expressions of both WT-KIT and activated PKC-δ and that expression of KIT is correlated with poor patient survival (P = 0.004). Continuous downstream signal activation after KIT-SCF binding is accomplished through PKC-δ-mediated recycling of KIT. This sustained KIT activation may contribute to tumor progression in a subset of colon cancers with KIT expression and might provide the rationale for a therapeutic approach targeting KIT. ©2013 AACR.

A novel gene, MdSSK1, as a component of the SCF complex rather than MdSBP1 can mediate the ubiquitination of S-RNase in apple.

PubMed

Yuan, Hui; Meng, Dong; Gu, Zhaoyu; Li, Wei; Wang, Aide; Yang, Qing; Zhu, Yuandi; Li, Tianzhong

2014-07-01

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. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

An analytical derivation of MC-SCF vibrational wave functions for the quantum dynamical simulation of multiple proton transfer reactions: Initial application to protonated water chains

NASA Astrophysics Data System (ADS)

Drukker, Karen; Hammes-Schiffer, Sharon

1997-07-01

This paper presents an analytical derivation of a multiconfigurational self-consistent-field (MC-SCF) solution of the time-independent Schrödinger equation for nuclear motion (i.e. vibrational modes). This variational MC-SCF method is designed for the mixed quantum/classical molecular dynamics simulation of multiple proton transfer reactions, where the transferring protons are treated quantum mechanically while the remaining degrees of freedom are treated classically. This paper presents a proof that the Hellmann-Feynman forces on the classical degrees of freedom are identical to the exact forces (i.e. the Pulay corrections vanish) when this MC-SCF method is used with an appropriate choice of basis functions. This new MC-SCF method is applied to multiple proton transfer in a protonated chain of three hydrogen-bonded water molecules. The ground state and the first three excited state energies and the ground state forces agree well with full configuration interaction calculations. Sample trajectories are obtained using adiabatic molecular dynamics methods, and nonadiabatic effects are found to be insignificant for these sample trajectories. The accuracy of the excited states will enable this MC-SCF method to be used in conjunction with nonadiabatic molecular dynamics methods. This application differs from previous work in that it is a real-time quantum dynamical nonequilibrium simulation of multiple proton transfer in a chain of water molecules.

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

USDA-ARS?s Scientific Manuscript database

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...

Non-linear eigensolver-based alternative to traditional SCF methods

NASA Astrophysics Data System (ADS)

Gavin, B.; Polizzi, E.

2013-05-01

The self-consistent procedure in electronic structure calculations is revisited using a highly efficient and robust algorithm for solving the non-linear eigenvector problem, i.e., H({ψ})ψ = Eψ. This new scheme is derived from a generalization of the FEAST eigenvalue algorithm to account for the non-linearity of the Hamiltonian with the occupied eigenvectors. Using a series of numerical examples and the density functional theory-Kohn/Sham model, it will be shown that our approach can outperform the traditional SCF mixing-scheme techniques by providing a higher converge rate, convergence to the correct solution regardless of the choice of the initial guess, and a significant reduction of the eigenvalue solve time in simulations.

The SCF ubiquitin ligase Slimb controls Nerfin-1 turnover in Drosophila.

PubMed

Lin, Xiaohui; Wang, Feng; Li, Yuanpei; Zhai, Chaojun; Wang, Guiping; Zhang, Xiaoting; Gao, Yang; Yi, Tao; Sun, Dan; Wu, Shian

2018-01-01

The C2H2 type zinc-finger transcription factor Nerfin-1 expresses dominantly in Drosophila nervous system and plays an important role in early axon guidance decisions and preventing neurons dedifferentiation. Recently, increasing reports indicated that INSM1 (homologue to nerfin-1 in mammals) is a useful marker for prognosis of neuroendocrine tumors. The dynamic expression of Nerfin-1 is regulated post-transcriptionally by multiple microRNAs; however, its post-translational regulation is still unclear. Here we showed that the protein turnover of Nerfin-1 is regulated by Slimb, the substrate adaptor of SCF Slimb ubiquitin ligase complex. Mechanistically, Slimb associates with Nerfin-1 and promotes it ubiquitination and degradation in Drosophila S2R + cells. Furthermore, we determined that the C-terminal half of Nerfin-1 (Nerfin-1 CT ) is required for its binding to Slimb. Genetic epistasis assays showed that Slimb misexpression antagonizes, while knock-down enhances the activity of Nerfin-1 CT in Drosophila eyes. Our data revealed a new link to understand the underlying mechanism for Nerfin-1 turnover in post-translational level, and provided useful insights in animal development and disease treatment by manipulating the activity of Slimb and Nerfin-1. Copyright © 2017 Elsevier Inc. All rights reserved.

A numerical fragment basis approach to SCF calculations.

NASA Astrophysics Data System (ADS)

Hinde, Robert J.

1997-11-01

The counterpoise method is often used to correct for basis set superposition error in calculations of the electronic structure of bimolecular systems. One drawback of this approach is the need to specify a ``reference state'' for the system; for reactive systems, the choice of an unambiguous reference state may be difficult. An example is the reaction F^- + HCl arrow HF + Cl^-. Two obvious reference states for this reaction are F^- + HCl and HF + Cl^-; however, different counterpoise-corrected interaction energies are obtained using these two reference states. We outline a method for performing SCF calculations which employs numerical basis functions; this method attempts to eliminate basis set superposition errors in an a priori fashion. We test the proposed method on two one-dimensional, three-center systems and discuss the possibility of extending our approach to include electron correlation effects.

Computer assisted generation of the matrix elements between contracted wavefunctions in a Complete Active Space scheme

NASA Astrophysics Data System (ADS)

Angeli, C.; Cimiraglia, R.

2005-02-01

Starting from a CAS-SCF calculation a sequence of contracted functions can be generated by applying strings of spin-traced replacement operators to the CAS-SCF solution. The laborious task of producing the Hamiltonian matrix elements between such functions can be substantially reduced making use of a computer algebra system. An implementation employing the MuPAD system is presented and illustrated.

Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium.

PubMed

Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng; Mitchell, Hugh; Gaffrey, Matt; Orr, Galya; DeAngelis, Kristen M

2017-01-01

The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growth conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, mid-exponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.

A Cullin1-Based SCF E3 Ubiquitin Ligase Targets the InR/PI3K/TOR Pathway to Regulate Neuronal Pruning

PubMed Central

Wong, Jack Jing Lin; Wang, Cheng; Zhang, Heng; Kirilly, Daniel; Wu, Chunlai; Liou, Yih-Cherng; Wang, Hongyan; Yu, Fengwei

2013-01-01

Pruning that selectively eliminates unnecessary axons/dendrites is crucial for sculpting the nervous system during development. During Drosophila metamorphosis, dendrite arborization neurons, ddaCs, selectively prune their larval dendrites in response to the steroid hormone ecdysone, whereas mushroom body γ neurons specifically eliminate their axon branches within dorsal and medial lobes. However, it is unknown which E3 ligase directs these two modes of pruning. Here, we identified a conserved SCF E3 ubiquitin ligase that plays a critical role in pruning of both ddaC dendrites and mushroom body γ axons. The SCF E3 ligase consists of four core components Cullin1/Roc1a/SkpA/Slimb and promotes ddaC dendrite pruning downstream of EcR-B1 and Sox14, but independently of Mical. Moreover, we demonstrate that the Cullin1-based E3 ligase facilitates ddaC dendrite pruning primarily through inactivation of the InR/PI3K/TOR pathway. We show that the F-box protein Slimb forms a complex with Akt, an activator of the InR/PI3K/TOR pathway, and promotes Akt ubiquitination. Activation of the InR/PI3K/TOR pathway is sufficient to inhibit ddaC dendrite pruning. Thus, our findings provide a novel link between the E3 ligase and the InR/PI3K/TOR pathway during dendrite pruning. PMID:24068890

[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.

Ab initio SCF calculations on the potential energy surface of potassium cyanide (KCN)

NASA Astrophysics Data System (ADS)

Wormer, Paul E. S.; Tennyson, Jonathan

1981-08-01

The potential energy surface of KCN has been generated by ab initio SCF calculations in the region of equilibrium bond distances. An analytic representation of the surface is presented. The calculations show that the bonding between K and CN is ionic, and that the structure of KCN is triangular, which confirms recent experimental findings. The computed geometry is &KCN = 62.4°, rCK = 5.492a0, and rCN = 2.186a0.

Induction of NKCF-like activity in mixed lymphocyte-tumor cell culture: direct involvement of mycoplasma infection of tumor cells.

PubMed

Wayner, E A; Brooks, C G

1984-04-01

Co-culture of CBA/J spleen cells and certain lines of YAC-1 stimulators resulted in the appearance of NKCF-like activity in 24- to 48-hr supernatants. Numerous other in vitro cell lines were effective stimulators of this splenic cytotoxic factor (SCF). The cells participating in SCF production were absent from normal thymocytes and were present in BALB/c nu/nu spleen, were nonadherent, asialo GM1+, and bore low levels of Thy-1.2. SCF could mediate lysis of certain NK-sensitive tumor targets in an 18-hr 51Cr-release assay. However, the induction of SCF was not correlated with the ability of a particular cell line to be lysed by NK cells, but showed an absolute correlation with the presence of mycoplasma contamination in cultured tumor cell lines. Mycoplasma negative cell lines, including an uninfected but NK-sensitive subline of YAC-1, were unable to induce SCF. Decontamination of mycoplasma-infected lines with antibiotics or by passage through syngeneic mice abrogated the ability of infected tumor cells to stimulate SCF. The ability to induce SCF could be restored by reinfection with mycoplasma. Tumor cell-free supernatants from contaminated cultures were mitogenic for CBA spleen cells and could themselves induce SCF activity in spleen cell supernatants. SCF production and the agent responsible could be removed by passing such supernatants through 0.1-micron filters. The organism apparently responsible for SCF induction from CBA spleen cells was typed and found to be Mycoplasma orale, a nonfermentative, arginine-dependent, common tissue culture contaminant. About 50 to 60% of SCF activity could be removed by 0.1-micron filters, suggesting that SCF is composed of two components: mycoplasma organisms themselves and a soluble cytotoxic factor produced in response to mycoplasma.

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.

Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng

The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growthmore » conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, mid-exponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.« less

Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng

The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growthmore » conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, midexponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.« less

Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium

PubMed Central

Chaput, Gina; Markillie, Lye Meng; Mitchell, Hugh; Gaffrey, Matt; Orr, Galya; DeAngelis, Kristen M.

2017-01-01

The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growth conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, mid-exponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future. PMID:29049419

Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium

DOE PAGES

Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng; ...

2017-10-19

The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growthmore » conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, mid-exponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.« less

Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca

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 tomore » 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.« less

75 FR 69088 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

... Strengthening Communities Fund and progress toward the objective of improving the capacity of organizations... Information Collection Activity; Comment Request Proposed Projects Title: Strengthening Communities Fund (SCF... information from participants in two Strengthening Communities Fund (SCF) programs: The Nonprofit Capacity...

Multifunction Sr, Co and F co-doped microporous coating on titanium of antibacterial, angiogenic and osteogenic activities

PubMed Central

Zhou, Jianhong; Zhao, Lingzhou

2016-01-01

Advanced multifunction titanium (Ti) based bone implant with antibacterial, angiogenic and osteogenic activities is stringently needed in clinic, which may be accomplished via incorporation of proper inorganic bioactive elements. In this work, microporous TiO2/calcium-phosphate coating on Ti doped with strontium, cobalt and fluorine (SCF-TiCP) was developed, which had a hierarchical micro/nano-structure with a microporous structure evenly covered with nano-grains. SCF-TiCP greatly inhibited the colonization and growth of both gram-positive and gram-negative bacteria. No cytotoxicity appeared for SCF-TiCP. Furthermore, SCF-TiCP stimulated the expression of key angiogenic factors in rat bone marrow stem cells (MSCs) and dramatically enhanced MSC osteogenic differentiation. The in vivo animal test displayed that SCF-TiCP induced more new bone and tighter implant/bone bonding. In conclusion, multifunction SCF-TiCP of antibacterial, angiogenic and osteogenic activities is a promising orthopedic and dental Ti implant coating for improved clinical performance. PMID:27353337

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavrielides, A.; Duguet, T., E-mail: thomas.duguet@ensiacet.fr, E-mail: Paul.Bagus@unt.edu; Esvan, J.

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 accuratemore » 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.« less

Design of Recombinant Stem Cell Factor macrophage Colony Stimulating Factor Fusion Proteins and their Biological Activity In Vitro

NASA Astrophysics Data System (ADS)

Chen, Tao; Yang, Jie; Wang, Yuelang; Zhan, Chenyang; Zang, Yuhui; Qin, Junchuan

2005-05-01

Stem cell factor (SCF) and macrophage colony stimulating factor (M-CSF) can act in synergistic way to promote the growth of mononuclear phagocytes. SCF-M-CSF fusion proteins were designed on the computer using the Homology and Biopolymer modules of the software packages InsightII. Several existing crystal structures were used as templates to generate models of the complexes of receptor with fusion protein. The structure rationality of the fusion protein incorporated a series of flexible linker peptide was analyzed on InsightII system. Then, a suitable peptide GGGGSGGGGSGG was chosen for the fusion protein. Two recombinant SCF-M-CSF fusion proteins were generated by construction of a plasmid in which the coding regions of human SCF (1-165aa) and M-CSF (1-149aa) cDNA were connected by this linker peptide coding sequence followed by subsequent expression in insect cell. The results of Western blot and activity analysis showed that these two recombinant fusion proteins existed as a dimer with a molecular weight of 84 KD under non-reducing conditions and a monomer of 42 KD at reducing condition. The results of cell proliferation assays showed that each fusion protein induced a dose-dependent proliferative response. At equimolar concentration, SCF/M-CSF was about 20 times more potent than the standard monomeric SCF in stimulating TF-1 cell line growth, while M-CSF/SCF was 10 times of monomeric SCF. No activity difference of M-CSF/SCF or SCF/M-CSF to M-CSF (at same molar) was found in stimulating the HL-60 cell linear growth. The synergistic effect of SCF and M-CSF moieties in the fusion proteins was demonstrated by the result of clonogenic assay performed with human bone mononuclear, in which both SCF/M-CSF and M-CSF/SCF induced much higher number of CFU-M than equimolar amount of SCF or M-CSF or that of two cytokines mixture.

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.

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.

Polyubiquitination of the B-cell translocation gene 1 and 2 proteins is promoted by the SCF ubiquitin ligase complex containing βTrCP.

PubMed

Sasajima, Hitoshi; Nakagawa, Koji; Kashiwayanagi, Makoto; Yokosawa, Hideyoshi

2012-01-01

B-cell translocation gene 1 and 2 (BTG1 and BTG2) are members of the BTG/Tob antiproliferative protein family, which is able to regulate the cell cycle and cell proliferation. We previously reported that BTG1, BTG2, Tob, and Tob2 are degraded via the ubiquitin-proteasome pathway. In this study, we investigated the mechanism of polyubiquitination of BTG1 and BTG2. Since the Skp1-Cdc53/Cullin 1-F-box protein (SCF) complex functions as one of the major ubiquitin ligases for cell cycle regulation, we first examined interactions between BTG proteins and components of the SCF complex, and found that BTG1 and BTG2 were capable of interacting with the SCF complex containing Cullin-1 (a scaffold protein) and Skp1 (a linker protein). As the SCF complex can ubiquitinate various target proteins by substituting different F-box proteins as subunits that recognize different target proteins, we next examined which F-box proteins could bind the two BTG proteins, and found that Skp2, β-transducin repeat-containing protein 1 (βTrCP1), and βTrCP2 were able to associate with both BTG1 and BTG2. Furthermore, we obtained evidence showing that βTrCP1 enhanced the polyubiquitination of both BTG1 and BTG2 more efficiently than Skp2 did, and that an F-box truncated mutant of βTrCP1 had a dominant negative effect on this polyubiquitination. Thus, we propose that BTG1 and BTG2 are subjected to polyubiquitination, more efficiently when it is mediated by SCFβTrCP than by SCFSkp2.

SCF(TIR1/AFB)-auxin signalling regulates PIN vacuolar trafficking and auxin fluxes during root gravitropism.

PubMed

Baster, Paweł; Robert, Stéphanie; Kleine-Vehn, Jürgen; Vanneste, Steffen; Kania, Urszula; Grunewald, Wim; De Rybel, Bert; Beeckman, Tom; Friml, Jiří

2013-01-23

The distribution of the phytohormone auxin regulates many aspects of plant development including growth response to gravity. Gravitropic root curvature involves coordinated and asymmetric cell elongation between the lower and upper side of the root, mediated by differential cellular auxin levels. The asymmetry in the auxin distribution is established and maintained by a spatio-temporal regulation of the PIN-FORMED (PIN) auxin transporter activity. We provide novel insights into the complex regulation of PIN abundance and activity during root gravitropism. We show that PIN2 turnover is differentially regulated on the upper and lower side of gravistimulated roots by distinct but partially overlapping auxin feedback mechanisms. In addition to regulating transcription and clathrin-mediated internalization, auxin also controls PIN abundance at the plasma membrane by promoting their vacuolar targeting and degradation. This effect of elevated auxin levels requires the activity of SKP-Cullin-F-box(TIR1/AFB) (SCF(TIR1/AFB))-dependent pathway. Importantly, also suboptimal auxin levels mediate PIN degradation utilizing the same signalling pathway. These feedback mechanisms are functionally important during gravitropic response and ensure fine-tuning of auxin fluxes for maintaining as well as terminating asymmetric growth.

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.

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".

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

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

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.

A framework for evaluating national space activity

NASA Astrophysics Data System (ADS)

Wood, Danielle; Weigel, Annalisa

2012-04-01

Space technology and resources are used around the world to address societal challenges. Space provides valuable satellite services, unique scientific discoveries, surprising technology applications and new economic opportunities. Many developing countries formally recognize the advantages of space resources and pursue national level activity to harness them. There is limited data or documentation on the space activities of developing countries. Meanwhile, traditional approaches to summarize national space activity do not necessarily capture the types of activity that developing countries pursue in space. This is especially true if they do not have a formal national space program or office. Developing countries pursue national space activity through activities of many types—from national satellite programs to commercial use of satellite services to involvement with international space institutions. This research aims to understand and analyze these trends. This paper introduces two analytical frameworks for evaluating space activity at the national level. The frameworks are specifically designed to capture the activity of countries that have traditionally been less involved in space. They take a broad view of space related activity across multiple societal sectors and disciplines. The discussion explains the approach for using the frameworks as well as illustrative examples of how they can be applied as part of a research process. The first framework is called the Mission and Management Ladders. This framework considers specific space projects within countries and ranks them on "Ladders" that measure technical challenge and managerial autonomy. This first method is at a micro level of analysis. The second framework is called the Space Participation Metric (SPM). The SPM can be used to assign a Space Participation score to countries based on their involvement in various space related activities. This second method uses a macro level of analysis. The authors

Dryer cuts fuel usage by equivalent of 6-million scf/yr

DOE Office of Scientific and Technical Information (OSTI.GOV)

List, K.H.; Powers, J.

Drying is an integral part of the production of ZnO pellets, a specific requirement for producing a uniform end product. The dryer has to be able to cure the product for a finite period at temperatures up to 500/sup 0/C in the same unit. Substantial savings have been realized because the dryer has enabled the user to optimize operating conditions. Continuous on-stream operations requiring minimum operator attendance, automatic controls, simplicity of design contruction, and the unit's ability to use waste heat also contribute to these savings. Gas exhausted from a nearby kiln provides the total heat requirement for the dryer.more » Positive delivery of the hot flue gas is assured by a blower and automatically controlled dampers. Annual fuel savings based on the use of waste heat, amounts to an equiv of 6 million scf of natural gas. 1 figure.« less

Ab initio study of Fe(+)-benzyne

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.

1993-01-01

The interaction of Fe(+) with benzyne is studied using the self-consistent-field (SCF), complete active space SCF, and modified-coupled-pair functional levels of theory. The most stable structure is planar, where the Fe(+) has inserted into the in-plane pi bond, although the C-C bond distance suggests that some in-plane pi bonding remains. This system is compared with Sc(+) bonding to benzyne and other ligands.

IASM: Individualized activity space modeler

NASA Astrophysics Data System (ADS)

Hasanzadeh, Kamyar

2018-01-01

Researchers from various disciplines have long been interested in analyzing and describing human mobility patterns. Activity space (AS), defined as an area encapsulating daily human mobility and activities, has been at the center of this interest. However, given the applied nature of research in this field and the complexity that advanced geographical modeling can pose to its users, the proposed models remain simplistic and inaccurate in many cases. Individualized Activity Space Modeler (IASM) is a geographic information system (GIS) toolbox, written in Python programming language using ESRI's Arcpy module, comprising four tools aiming to facilitate the use of advanced activity space models in empirical research. IASM provides individual-based and context-sensitive tools to estimate home range distances, delineate activity spaces, and model place exposures using individualized geographical data. In this paper, we describe the design and functionality of IASM, and provide an example of how it performs on a spatial dataset collected through an online map-based survey.

Stargate GTM: Bridging Descriptor and Activity Spaces.

PubMed

Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

2015-11-23

Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.

Using SCC8, SCF27 and VMC7f2 markers in grapevine breeding for seedlessness via marker assisted selection.

PubMed

Akkurt, M; Çakır, A; Shidfar, M; Çelikkol, B P; Söylemezoğlu, G

2012-08-13

We used molecular markers associated with seedlessness in grapes, namely SCC8, SCF27 and VMC7f2, to improve the efficiency of seedless grapevine breeding via marker assisted selection (MAS). DNA from 372 F₁ hybrid progeny from the cross between seeded "Alphonse Lavallée" and seedless "Sultani" was amplified by PCR using three markers. After digestion of SCC8 marker amplification products by restriction enzyme BgIII, 40 individuals showed homozygous SCC8+/SCC8+ alleles at the seed development inhibitor (SdI) locus. DNA from 80 of the progeny amplified with the SCF27 marker produced bands; 174 individuals had 198-bp alleles of the VMC7f2 marker associated with seedlessness. In the second year, based on MAS, 183 F₁ hybrids were designated as seedless grapevine candidates because they were positive for a minimum of one marker. Twenty individuals were selected as genetic resources for future studies on seedless grapevine breeding because they carried alleles for the three markers associated with seedlessness. The VMC7f2 SSR marker was identified as the marker most associated with seedlessness.

Caspase-activated ROCK-1 allows erythroblast terminal maturation independently of cytokine-induced Rho signaling

PubMed Central

Gabet, A-S; Coulon, S; Fricot, A; Vandekerckhove, J; Chang, Y; Ribeil, J-A; Lordier, L; Zermati, Y; Asnafi, V; Belaid, Z; Debili, N; Vainchenker, W; Varet, B; Hermine, O; Courtois, G

2011-01-01

Stem cell factor (SCF) and erythropoietin are strictly required for preventing apoptosis and stimulating proliferation, allowing the differentiation of erythroid precursors from colony-forming unit-E to the polychromatophilic stage. In contrast, terminal maturation to generate reticulocytes occurs independently of cytokine signaling by a mechanism not fully understood. Terminal differentiation is characterized by a sequence of morphological changes including a progressive decrease in cell size, chromatin condensation in the nucleus and disappearance of organelles, which requires transient caspase activation. These events are followed by nucleus extrusion as a consequence of plasma membrane and cytoskeleton reorganization. Here, we show that in early step, SCF stimulates the Rho/ROCK pathway until the basophilic stage. Thereafter, ROCK-1 is activated independently of Rho signaling by caspase-3-mediated cleavage, allowing terminal maturation at least in part through phosphorylation of the light chain of myosin II. Therefore, in this differentiation system, final maturation occurs independently of SCF signaling through caspase-induced ROCK-1 kinase activation. PMID:21072057

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

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.

Activities on space debris in Europe

NASA Astrophysics Data System (ADS)

Flury, W.

2001-10-01

Activities on space debris in Europe are carried out by ESA, by national space agencies such as ASI (Italy), BNSC (United Kingdom), CNES (France) and DLR (Germany) and by various research groups. The objectives of ESA's activities in the field of space debris have been defined by the Council of ESA in 1989, and were updated in 2000 with the adoption of the Resolution for a European policy on the protection of the space environment from debris. ESA's debris-related activities comprise research, application of debris mitigation measures and international cooperation. The research activities address the knowledge of the terrestrial particulate environment, risk assessment, hypervelocity impacts and protection, and preventative measures. In all these areas substantial progress has been achieved. Examples are the MASTER 99 model, the DISCOS database, beam-park experiments with the FGAN radar, the discovery of a small-size debris population in GEO with the Space Debris telescope at the Teide observatory, and the GORID dust detector in the geostationary orbit. The ESA Space Debris Mitigation Handbook was issued, and in a joint effort of ESA and the national agencies ASI, BNSC, CNES and DLR the European Space Debris Safety and Mitigation Standard (draft) was established. This standard will be harmonized with standards of other agencies through the deliberations in the Inter-Agency Space Debris Coordination Committee (IADC). In order to strengthen the European cooperation, the pilot network of centers - Working Group on Space Debris was created in 2000. The members are ESA, ASI, BNSC, CNES and DLR. An integrated work plan has been established for the period 2001-2003. Global cooperation among the space-faring nations is achieved through the IADC. ESA and its Member States strongly support the deliberations on space debris within the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS).

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

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

DOE PAGES

Mudhasani, Rajini; Tran, Julie P.; Retterer, Cary; ...

2016-02-02

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 anmore » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mudhasani, Rajini; Tran, Julie P.; Retterer, Cary

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 anmore » 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.« less

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.

Space weather activities in Europe

NASA Astrophysics Data System (ADS)

Wimmer-Schweingruber, R. F.

The Sun has long been understood as a source of energy for mankind. Only in the more modern times has it also been seen as a source of disturbances in the space environment of the Earth, but also of the other planets and the heliosphere. Space weather research had an early start in Europe with investigations of Birkeland, Fitzgerald and Lodge, ultimately leading to an understanding of geomagnetic storms and their relation to the Sun. Today, European space weather activities range from the study of the Sun, through the inner heliosphere, to the magnetosphere, ionosphere, atmosphere, down to ground level effects. We will give an overview of European space weather activities and focus on the chain of events from Sun to Earth.

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.

Rice black streaked dwarf virus P7-2 forms a SCF complex through binding to Oryza sativa SKP1-like proteins, and interacts with GID2 involved in the gibberellin pathway.

PubMed

Tao, Tao; Zhou, Cui-Ji; Wang, Qian; Chen, Xiang-Ru; Sun, Qian; Zhao, Tian-Yu; Ye, Jian-Chun; Wang, Ying; Zhang, Zong-Ying; Zhang, Yong-Liang; Guo, Ze-Jian; Wang, Xian-Bing; Li, Da-Wei; Yu, Jia-Lin; Han, Cheng-Gui

2017-01-01

As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1) plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA), jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV), a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK) proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2) from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection.

Rice black streaked dwarf virus P7-2 forms a SCF complex through binding to Oryza sativa SKP1-like proteins, and interacts with GID2 involved in the gibberellin pathway

PubMed Central

Wang, Qian; Chen, Xiang-Ru; Sun, Qian; Zhao, Tian-Yu; Ye, Jian-Chun; Wang, Ying; Zhang, Zong-Ying; Zhang, Yong-Liang; Guo, Ze-Jian; Wang, Xian-Bing; Li, Da-Wei; Yu, Jia-Lin

2017-01-01

As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1) plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA), jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV), a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK) proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2) from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection. PMID:28494021

The LAM space active optics facility

NASA Astrophysics Data System (ADS)

Engel, C.; Ferrari, M.; Hugot, E.; Escolle, C.; Bonnefois, A.; Bernot, M.; Bret-Dibat, T.; Carlavan, M.; Falzon, F.; Fusco, T.; Laubier, D.; Liotard, A.; Michau, V.; Mugnier, L.

2017-11-01

The next generation of large lightweight space telescopes will require the use of active optics systems to enhance the performance and increase the spatial resolution. Since almost 10 years now, LAM, CNES, THALES and ONERA conjugate their experience and efforts for the development of space active optics through the validation of key technological building blocks: correcting devices, metrology components and control strategies. This article presents the work done so far on active correcting mirrors and wave front sensing, as well as all the facilities implemented. The last part of this paper focuses on the merging of the MADRAS and RASCASSE test-set up. This unique combination will provide to the active optics community an automated, flexible and versatile facility able to feed and characterise space active optics components.

Structural Basis for Activation of the Receptor Tyrosine Kinase KIT by Stem Cell Factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuzawa,S.; Opatowsky, Y.; Zhang, Z.

2007-01-01

Stem Cell Factor (SCF) initiates its multiple cellular responses by binding to the ectodomain of KIT, resulting in tyrosine kinase activation. We describe the crystal structure of the entire ectodomain of KIT before and after SCF stimulation. The structures show that KIT dimerization is driven by SCF binding whose sole role is to bring two KIT molecules together. Receptor dimerization is followed by conformational changes that enable lateral interactions between membrane proximal Ig-like domains D4 and D5 of two KIT molecules. Experiments with cultured cells show that KIT activation is compromised by point mutations in amino acids critical for D4-D4more » interaction. Moreover, a variety of oncogenic mutations are mapped to the D5-D5 interface. Since key hallmarks of KIT structures, ligand-induced receptor dimerization, and the critical residues in the D4-D4 interface, are conserved in other receptors, the mechanism of KIT stimulation unveiled in this report may apply for other receptor activation.« less

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

Stennis hosts Space Day activities at USM

NASA Image and Video Library

2009-10-17

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.

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.

SCF-Xα-SW electron densities with the overlapping sphere approximation

NASA Astrophysics Data System (ADS)

McMaster, Blair N.; Smith, Vedene H., Jr.; Salahub, Dennis R.

Self consistent field-Xα-scattered wave (SCF-Xα-SW) calculations have been performed for a series of eight first and second row homonuclear diatomic molecules using both the touching (TS) and 25 per cent overlapping sphere (OS) versions. The OS deformation density maps exhibit much better quantitative agreement with those from other Xα methods, which do not employ the spherical muffin-tin (MT) potential approximation, than do the TS maps. The OS version thus compensates very effectively for the errors involved in the MT approximation in computing electron densities. A detailed comparison between the TS- and OS-Xα-SW orbitals reveals that the reasons for this improvement are surprisingly specific. The dominant effect of the OS approximation is to increase substantially the electron density near the midpoint of bonding σ orbitals, with a consequent reduction of the density behind the atoms. A similar effect occurs for the bonding π orbitals but is less pronounced. These effects are due to a change in hybridization of the orbitals, with the OS approximation increasing the proportion of the subdominant partial waves and hence changing the shapes of the orbitals. It is this increased orbital polarization which so effectively compensates for the lack of (non-spherically symmetric) polarization components in the MT potential, when overlapping spheres are used.

Extravehicular activity space suit interoperability.

PubMed

Skoog, A I; McBarron JW 2nd; Severin, G I

1995-10-01

The European Agency (ESA) and the Russian Space Agency (RKA) are jointly developing a new space suit system for improved extravehicular activity (EVA) capabilities in support of the MIR Space Station Programme, the EVA Suit 2000. Recent national policy agreements between the U.S. and Russia on planned cooperations in manned space also include joint extravehicular activity (EVA). With an increased number of space suit systems and a higher operational frequency towards the end of this century an improved interoperability for both routine and emergency operations is of eminent importance. It is thus timely to report the current status of ongoing work on international EVA interoperability being conducted by the Committee on EVA Protocols and Operations of the International Academy of Astronauts initiated in 1991. This paper summarises the current EVA interoperability issues to be harmonised and presents quantified vehicle interface requirements for the current U.S. Shuttle EMU and Russian MIR Orlan DMA and the new European/Russian EVA Suit 2000 extravehicular systems. Major critical/incompatible interfaces for suits/mother-craft of different combinations are discussed, and recommendations for standardisations given.

NASA Space Environments Technical Discipline Team Space Weather Activities

NASA Astrophysics Data System (ADS)

Minow, J. I.; Nicholas, A. C.; Parker, L. N.; Xapsos, M.; Walker, P. W.; Stauffer, C.

2017-12-01

The Space Environment Technical Discipline Team (TDT) is a technical organization led by NASA's Technical Fellow for Space Environments that supports NASA's Office of the Chief Engineer through the NASA Engineering and Safety Center. The Space Environments TDT conducts independent technical assessments related to the space environment and space weather impacts on spacecraft for NASA programs and provides technical expertise to NASA management and programs where required. This presentation will highlight the status of applied space weather activities within the Space Environment TDT that support development of operational space weather applications and a better understanding of the impacts of space weather on space systems. We will first discuss a tool that has been developed for evaluating space weather launch constraints that are used to protect launch vehicles from hazardous space weather. We then describe an effort to better characterize three-dimensional radiation transport for CubeSat spacecraft and processing of micro-dosimeter data from the International Space Station which the team plans to make available to the space science community. Finally, we will conclude with a quick description of an effort to maintain access to the real-time solar wind data provided by the Advanced Composition Explorer satellite at the Sun-Earth L1 point.

Green space definition affects associations of green space with overweight and physical activity.

PubMed

Klompmaker, Jochem O; Hoek, Gerard; Bloemsma, Lizan D; Gehring, Ulrike; Strak, Maciej; Wijga, Alet H; van den Brink, Carolien; Brunekreef, Bert; Lebret, Erik; Janssen, Nicole A H

2018-01-01

In epidemiological studies, exposure to green space is inconsistently associated with being overweight and physical activity, possibly because studies differ widely in their definition of green space exposure, inclusion of important confounders, study population and data analysis. We evaluated whether the association of green space with being overweight and physical activity depended upon definition of greenspace. We conducted a cross-sectional study using data from a Dutch national health survey of 387,195 adults. Distance to the nearest park entrance and surrounding green space, based on the Normalized Difference Vegetation Index (NDVI) or a detailed Dutch land-use database (TOP10NL), was calculated for each residential address. We used logistic regression analyses to study the association of green space exposure with being overweight and being moderately or vigorously physically active outdoors at least 150min/week (self-reported). To study the shape of the association, we specified natural splines and quintiles. The distance to the nearest park entrance was not associated with being overweight or outdoor physical activity. Associations of surrounding green space with being overweight or outdoor physical activity were highly non-linear. For NDVI surrounding greenness, we observed significantly decreased odds of being overweight [300m buffer, odds ratio (OR) = 0.88; 95% CI: 0.86, 0.91] and increased odds for outdoor physical activity [300m buffer, OR = 1.14; 95% CI: 1.10, 1.17] in the highest quintile compared to the lowest quintile. For TOP10NL surrounding green space, associations were mostly non-significant. Associations were generally stronger for subjects living in less urban areas and for the smaller buffers. Associations of green space with being overweight and outdoor physical activity differed considerably between different green space definitions. Associations were strongest for NDVI surrounding greenness. Copyright © 2017 The Authors. Published by

Electronic structure for the ground state of TlH from relativistic multiconfiguration SCF calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christiansen, P.A.; Pitzer, K.S.

The dissociation curve for the ground state of TlH was computed using a relativistic ..omega..--..omega.. coupling formalism. The relativistic effects represented by the Dirac equation were introduced using effective potentials generated from atomic Dirac--Fock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. The multiconfiguration SCF treatment used is a generalization of the two-component molecular spinor formalism of Lee, Ermler, and Pitzer. Using a five configuration wave function we were able to obtain approximately 85% of the experimental dissociation energy. Our computations indicate that the bond is principally sigma in form, despite themore » large spin--orbit splitting in atomic thallium. Furthermore the bond appears to be slightly ionic (Tl/sup +/H/sup -/) with about 0.3 extra electron charge on the hydrogen.« less

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.

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.

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.

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.

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.

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

Activating Public Space: How to Promote Physical Activity in Urban Environment

NASA Astrophysics Data System (ADS)

Kostrzewska, Małgorzata

2017-10-01

Physical activity is an essential component of a healthy lifestyle. The quality and equipment of urban public space plays an important role in promoting physical activity among people (residents, tourists). In order for recreation and sports activities to be undertaken willingly, in a safe and comprehensive manner, certain spatial conditions and requirements must be met. The distinctive feature of contemporary large cities is the disappearance of local, neighbourly relations, and the consequent loneliness, alienation, and atomization of the residents. Thus, the design of public spaces should be an expression of the values of social inclusion and integration. A properly designed urban space would encourage people to leave their homes and integrate, also by undertaking different forms of physical activities. This, in turn, can lead to raising the quality of the space, especially in the context of its “familiarization” and “domestication”. The aim of the research was to identify the architectural and urban features of the public spaces of contemporary cities that can contribute to the promotion of physical activity. The paper presents the research results and the case studies of such spatial solutions and examples of good practices, which invite residents to undertake different forms of physical activities in public spaces. The issue of the integrating, inclusionary, and social function of physical recreation and sport is discussed as well, and so are the possibilities of translating these values into physical characteristics of an urban space. The main conclusions are that taking into account the diverse needs of different social groups, participation in the design and construction process, aesthetic and interesting design, vicinity of the residence, open access for all age groups and the disabled would be the most important spatial determinants of a properly designed, physically activating public space. Strategies of planning the sports and recreation

NASA's current activities in free space optical communications

NASA Astrophysics Data System (ADS)

Edwards, Bernard L.

2017-11-01

NASA and other space agencies around the world are currently developing free space optical communication systems for both space-to-ground links and space-to-space links. This paper provides an overview of NASA's current activities in free space optical communications with a focus on Near Earth applications. Activities to be discussed include the Lunar Laser Communication Demonstration, the Laser Communications Relay Demonstration, and the commercialization of the underlying technology. The paper will also briefly discuss ongoing efforts and studies for Deep Space optical communications. Finally the paper will discuss the development of international optical communication standards within the Consultative Committee for Space Data Systems.

A Peek into a Cul-De-Sac and a Mews of Martian Dust Storm Activity: Western Hellas and Syria-Claritas Fossae During Mars Year 29

NASA Astrophysics Data System (ADS)

Heavens, N. G.

2016-12-01

Western Hellas Planitia (WHP) and the region encompassed by Syria Planum and Claritas Fossae are the main centers of textured dust storm activity in Mars's southern low to mid-latitudes. (Texture in this context refers to distinct fine structure at the cloud tops indicative of active lifting.) WHP is a well-known initiation zone for regional and global dust storm activity and often the end point of the Utopia "flushing storm" track. Syria-Claritas Fossae (SCF), too, can be a lifting center in global dust storm activity. Indeed, SCF and the area to its west was the region most denuded of dust by the Mars Year (MY) 25 global dust storm, perhaps suggesting that SCF contained the principal lifting center of the storm. Thus, if the Acidalia and Utopia storm tracks are Mars's dust storm alleys, through which dust storms pass quickly again and again; WHP might be a cul-de-sac and SCF something like a mews, where dust storm activity can enter more or less easily but may not as easily leave. In this presentation, I will focus on dust storm activity in these areas in a typical non-global dust storm year, MY 29. Synthesizing visible imagery by the Mars Color Imager (MARCI) on board Mars Reconnaissance Orbiter (MRO) and Mars Climate Sounder (MCS) also on board MRO, I will consider the climatology, morphology, texture, and vertical structure of dust storm activity in these areas in order to infer their governing dynamics. This investigation has two aims: (1) to understand why these areas are centers of textured dust storm activity; and (2) to connect the characteristics of smaller-scale dust storm activity in these regions to the underlying dynamics in order to understand the role of WHP and SCF in the dynamics of global dust storms. This work is supported by NASA's Mars Data Analysis Program (NNX14AM32G).

Peaceful Use of Outer Space: principles of Japanese Policies on Utilization and Activities in Outer space

NASA Astrophysics Data System (ADS)

Kosuge, Toshio

2002-01-01

" P e aceful use of outer space of outer space.....Principles of exploitation of outer space was passed in the Japanese Diet. It clearly mentioned that any activity of launching space object into outer space and developing launching rocket should be exclusively for peaceful purpose. NASDA was also established based upon the same principles of the public law. Japanese interpretation of Space Treaty and other related international agreements has been more strict on peaceful use of outer space, like non-military use rather than non-aggressive, because of influence of Japanese Constitution. Treaty and other agreements is analyzed through rapid development of its space activities, technologies and international cooperation with other space powers. Through more than thirty years experiences in space activities in public and private sectors, Japanese domestic laws and policies have not been changed in relation with basic principles. and laws relating to space activities in order to develop new space law and more international cooperation for space utilization rather than military use in new century.

SCF(JFK) is a bona fide E3 ligase for ING4 and a potent promoter of the angiogenesis and metastasis of breast cancer.

PubMed

Yan, Ruorong; He, Lin; Li, Zhongwu; Han, Xiao; Liang, Jing; Si, Wenzhe; Chen, Zhe; Li, Lei; Xie, Guojia; Li, Wanjin; Wang, Peiyan; Lei, Liandi; Zhang, Hongquan; Pei, Fei; Cao, Dengfeng; Sun, Luyang; Shang, Yongfeng

2015-03-15

Loss of function/dysregulation of inhibitor of growth 4 (ING4) and hyperactivation of NF-κB are frequent events in many types of human malignancies. However, the molecular mechanisms underlying these remarkable aberrations are not understood. Here, we report that ING4 is physically associated with JFK. We demonstrated that JFK targets ING4 for ubiquitination and degradation through assembly of an Skp1-Cul1-F-box (SCF) complex. We showed that JFK-mediated ING4 destabilization leads to the hyperactivation of the canonical NF-κB pathway and promotes angiogenesis and metastasis of breast cancer. Significantly, the expression of JFK is markedly up-regulated in breast cancer, and the level of JFK is negatively correlated with that of ING4 and positively correlated with an aggressive clinical behavior of breast carcinomas. Our study identified SCF(JFK) as a bona fide E3 ligase for ING4 and unraveled the JFK-ING4-NF-κB axis as an important player in the development and progression of breast cancer, supporting the pursuit of JFK as a potential target for breast cancer intervention. © 2015 Yan et al.; Published by Cold Spring Harbor Laboratory Press.

Overview of materials processing in space activity at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Williams, J. R.; Chassay, R. P.; Moore, W. W.; Ruff, R. C.; Yates, I. C.

1984-01-01

An overview of activities involving the Space Transportation System (STS), now in the operational phase, and results of some of the current space experiments, as well as future research opportunities in microgravity environment, are presented. The experiments of the Materials Processing in Space Program flown on the STS, such as bioseparation processes, isoelectric focusing, solidification and crystal growth processes, containerless processes, and the Materials Experiment Assembly experiments are discussed. Special consideration is given to the experiments to be flown aboard the Spacelab 3 module, the Fluids Experiments System, and the Vapor Crystal Growth System. Ground-based test facilities and planned space research facilities, as well as the nature of the commercialization activities, are briefly explained.

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.

New sesquiterpenes, JBIR-27 and -28, isolated from a tunicate-derived fungus, Penicillium sp. SS080624SCf1.

PubMed

Motohashi, Keiichiro; Hashimoto, Junko; Inaba, Shigeki; Khan, Shams Tabrez; Komaki, Hisayuki; Nagai, Aya; Takagi, Motoki; Shin-ya, Kazuo

2009-05-01

In the course of our screening program for novel metabolites from tunicate-derived fungi, novel sesquiterpenoids, named JBIR-27 (1) and -28 (2), together with known sporogen-AO1 and phomenone, were isolated from the culture broth of Penicillium sp. SS080624SCf1. The structures of 1 and 2 were determined to be eremophilane analogs on the basis of extensive NMR and MS analyses. Sporogen-AO1, phomenone and 2 showed cytotoxicity against human cervical carcinoma cell line HeLa at IC(50) values of 8.3, 19 and 92 microM, respectively, whereas 1 was inactive at a concentration of 80 microM.

ELECTRONIC STRUCTURE FOR THE GROUND STATE OF T1H FROM RELATIVISTIC MULTICONFIGURATION SCF CALCULATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christiansen, P.A.; Pitzer, K.S.

The dissociation curve for the ground state of TlH was computed using a relativistic {omega}-{omega} coupling formalism. The relativistic effects represented by the Dirac equation were introduced using effective potentials generated from atomic Dirac-Fock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. The multiconfiguration SCF treatment used is a generalization of the two-component molecular spinor formalism of Lee, Ermler, and Pitzer. Using a five configuration wave function we were able to obtain approximately 85% of the experimental dissociation energy. Our computations indicate that the bond is principally sigma in form, despite themore » large spin-orbit splitting in atomic thallium. Furthermore the bond appears to be slightly ionic (Tl{sup +}H{sup -}) with about 0.3 extra electron charge on the hydrogen.« less

Investigation of the Semicoa SCF9550 and the International Rectifier IRHM57260SE for Single-Event Gate Rapture and Single-Event Burnout : NASA Electronic Parts and Packaging (NEPP) Program Office of Safety and Mission Assurance

NASA Technical Reports Server (NTRS)

Scheick, Leif

2011-01-01

Single-event-effect test results for hi-rel total-dose-hardened power MOSFETs are presented in this report. TheSCF9550 from Semicoa and the IRHM57260SE from International Rectifier were tested to NASA test condition/standards and requirements.The IRHM57260SE performed much better when compared to previous testing. These initial results confirm that parts from the Temecula line are marginally comparable to the El Segundo line. The SCF9550 from Semicoa was also tested and represents the initial parts offering from this vendor. Both parts experienced single-event gate rupture (SEGR) and single-event burnout (SEB). All of the SEGR was from gate to drain.

Activity spaces among injection drug users in San Francisco.

PubMed

Martinez, Alexis N; Lorvick, Jennifer; Kral, Alex H

2014-05-01

Representations of activity spaces, defined as the local areas within which people move or travel in the course of their daily activities, are unexplored among injection drug users (IDUs). The purpose of this paper is to use an activity space framework to study place and drug user health. Data for this analysis is from an epidemiological study of street-recruited IDUs in San Francisco (N=1084). Study participants reported geographic intersections of where they most often slept at night, hung out during the day, and used drugs during a 6 month time period. We used GIS software to construct and map activity space routes of street-based network paths between these intersections. We further identified if syringe exchange program (SEP) locations intersected with, participant activity space routes. We used logistic regression to estimate associations between activity space variables and HIV serostatus, syringe sharing, and non-fatal overdose, after adjusting for individual and Census tract covariates. Mean activity space distance for all participants was 1.5miles. 9.6% of participants had a SEP located along their activity space. An increase in activity space distance was associated with a decrease in odds of being HIV positive. An increase in residential transience, or the number of different locations slept in by participants in a 6 month time period, was associated with higher odds of syringe sharing. Activity space distance was not independently associated with overdose or syringe sharing. Research that locates individuals in places of perceived importance is needed to inform placement and accessibility of HIV and overdose prevention programs. More attention needs to be given to the logistics of collecting sensitive geospatial data from vulnerable populations as well as how to maximize the use of GIS software for visualizing and understanding how IDUs interact with their environment. Copyright © 2013. Published by Elsevier B.V.

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.

75 FR 15438 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-29

... outcomes achieved by the Strengthening Communities Fund in meeting its objective of improving the capacity... Information Collection Activity; Comment Request Proposed Projects Title: Strengthening Communities Fund... to obtain evaluation information from Strengthening Communities Fund (SCF) grantees. Grantees include...

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.

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.

Fractography and the Surface Crack in Flexure (SCF) method for evaluating fracture toughness of ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinn, G.D.; Gettings, R.J.; Kuebler, J.J.

1996-12-31

The surface crack in flexure (SCF) method, also known as the controlled surface flaw method, has been used to measure fracture toughness of ceramics and glasses for almost 20 years. New fracture toughness results for a range of ceramics and glasses including alumina, boron carbide, silicon carbide, silicon nitride, titanium diboride, zirconia, glass ceramic, borosilicate crown glass, and a whisker-reinforced alumina are presented in this paper. Some materials are conducive to precrack measurements, while others are not. New techniques for detecting the precracks are presented. A surprising outcome from a recently concluded Versailles Advanced Materials and Standards (VAMAS) round robinmore » project was that the computed toughness is often not sensitive to the exact precrack size measurement. Consistent results were obtained by many laboratories despite different viewing modes and magnifications. The reasons for this consistency and why toughness is insensitive to precrack size is presented.« less

Latin American space activities based on different infrastructures

NASA Astrophysics Data System (ADS)

Gall, Ruth

The paper deals with recent basic space research and space applications in several Latin-American countries. It links space activities with national scientific and institutional infrastructures and stresses the importance of interdisciplinary space programs, that can play a major role in the developing countries achievement of self reliance in space matters.

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.

NASA SpaceWire Activities/Comments/Recommendations

NASA Technical Reports Server (NTRS)

Rakow, Glenn

2006-01-01

This viewgraph presentation reviews NASA's activities, and proposes recommendations for the further use of the SpaceWire (SpW). The areas covered in this presentation are: (1) Protocol ID assignment, (2) Protocol development, (3) Plug & Play (PnP), (4) Recommended additions t o SpW protocol and (5) SpaceFibre trade.

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.

Establishing space activities in non-space faring nations: An example of university-based strategic planning

NASA Astrophysics Data System (ADS)

Faure, Pauline; Cho, Mengu; Maeda, George

2018-07-01

In 2015, Kyushu Institute of Technology initiated the Joint Global Multi-Nation Birds Satellite (BIRDS) program. As of September 2017, young professionals from Bangladesh, Ghana, Nigeria, Thailand, Mongolia, Philippines, Malaysia, and Bhutan are being involved in BIRDS program. To help the young professionals acquiring the right tools and preparing them to successfully establish indigenous space activities, the space strategic planning project was established in February 2017. During the project, young professionals from Bangladesh, Ghana, Mongolia, and Bhutan were invited to think about the strategy their home country should be following in the next ten years to achieve their country's goals in terms of space sciences, engineering, and utilization, while respecting the country needs and constraints. In this paper, the efforts undertaken by the different young professionals are reported and the guidelines for each country space strategic planning are described. From this work, the authors aim at promoting space activities development in non-space faring nations and encouraging non-space faring nations to find their right strategy to achieve sustainable indigenous space activities despite the nation's constraints.

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

Qualitative GIS and the Visualization of Narrative Activity Space Data.

PubMed

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

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.

Orientia tsutsugamushi Strain Ikeda Ankyrin Repeat-Containing Proteins Recruit SCF1 Ubiquitin Ligase Machinery via Poxvirus-Like F-Box Motifs.

PubMed

Beyer, Andrea R; VieBrock, Lauren; Rodino, Kyle G; Miller, Daniel P; Tegels, Brittney K; Marconi, Richard T; Carlyon, Jason A

2015-10-01

A rising theme among intracellular microbes is the delivery of ankyrin repeat-containing effectors (Anks) that interact with target proteins to co-opt host cell functions. Orientia tsutsugamushi, an obligate intracellular bacterium and the etiologic agent of scrub typhus, encodes one of the largest Ank repertoires of any sequenced microorganism. They have been previously identified as type 1 secretion system substrates. Here, in silico and manual sequence analyses revealed that a large proportion of O. tsutsugamushi strain Ikeda Anks bear a eukaryotic/poxvirus-like F-box motif, which is known to recruit host cell SCF1 ubiquitin ligase machinery. We assessed the Anks for the ability to serve as F-box proteins. Coimmunoprecipitation assays demonstrated that F-box-containing Anks interact with overexpressed and/or endogenous SCF1 components. When coexpressed with FLAG-Ank4_01 or FLAG-Ank9, a glutathione S-transferase (GST)-tagged version of the SCF1 component SKP1 localized to subcellular sites of FLAG-Ank accumulation. The abilities of recombinant Anks to interact and colocalize with SKP1 were F-box dependent. GST-SKP1 precipitated O. tsutsugamushi-derived Ank9 from infected host cells, verifying both that the pathogen expresses Ank9 during infection and the protein's capability to bind SKP1. Aligning O. tsutsugamushi, poxviral, and eukaryotic F-box sequences delineated three F-box residues that are highly conserved and likely to be functionally important. Substitution of these residues ablated the ability of GFP-Ank9 to interact with GST-SKP1. These results demonstrate that O. tsutsugamushi strain Ikeda Anks can co-opt host cell polyubiquitination machinery, provide the first evidence that an O. tsutsugamushi Ank does so during infection, and advance overall understanding of microbial F-box proteins. Ankyrin repeat-containing proteins (Anks) are important virulence factors of intracellular bacteria that mediate protein-protein interactions with host cell targets

Orientia tsutsugamushi Strain Ikeda Ankyrin Repeat-Containing Proteins Recruit SCF1 Ubiquitin Ligase Machinery via Poxvirus-Like F-Box Motifs

PubMed Central

Beyer, Andrea R.; VieBrock, Lauren; Rodino, Kyle G.; Miller, Daniel P.; Tegels, Brittney K.; Marconi, Richard T.

2015-01-01

ABSTRACT A rising theme among intracellular microbes is the delivery of ankyrin repeat-containing effectors (Anks) that interact with target proteins to co-opt host cell functions. Orientia tsutsugamushi, an obligate intracellular bacterium and the etiologic agent of scrub typhus, encodes one of the largest Ank repertoires of any sequenced microorganism. They have been previously identified as type 1 secretion system substrates. Here, in silico and manual sequence analyses revealed that a large proportion of O. tsutsugamushi strain Ikeda Anks bear a eukaryotic/poxvirus-like F-box motif, which is known to recruit host cell SCF1 ubiquitin ligase machinery. We assessed the Anks for the ability to serve as F-box proteins. Coimmunoprecipitation assays demonstrated that F-box-containing Anks interact with overexpressed and/or endogenous SCF1 components. When coexpressed with FLAG-Ank4_01 or FLAG-Ank9, a glutathione S-transferase (GST)-tagged version of the SCF1 component SKP1 localized to subcellular sites of FLAG-Ank accumulation. The abilities of recombinant Anks to interact and colocalize with SKP1 were F-box dependent. GST-SKP1 precipitated O. tsutsugamushi-derived Ank9 from infected host cells, verifying both that the pathogen expresses Ank9 during infection and the protein's capability to bind SKP1. Aligning O. tsutsugamushi, poxviral, and eukaryotic F-box sequences delineated three F-box residues that are highly conserved and likely to be functionally important. Substitution of these residues ablated the ability of GFP-Ank9 to interact with GST-SKP1. These results demonstrate that O. tsutsugamushi strain Ikeda Anks can co-opt host cell polyubiquitination machinery, provide the first evidence that an O. tsutsugamushi Ank does so during infection, and advance overall understanding of microbial F-box proteins. IMPORTANCE Ankyrin repeat-containing proteins (Anks) are important virulence factors of intracellular bacteria that mediate protein-protein interactions with

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.

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)

International Cooperation and Competition in Civilian Space Activities.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

This report assesses the state of international competition in civilian space activities, explores United States civilian objectives in space, and suggests alternative options for enhancing the overall U.S. position in space technologies. It also investigated past, present, and projected international cooperative arrangements for space activities…

Active Space Dependence in Multiconfiguration Pair-Density Functional Theory.

PubMed

Sharma, Prachi; Truhlar, Donald G; Gagliardi, Laura

2018-02-13

In multiconfiguration pair-density functional theory (MC-PDFT), multiconfiguration self-consistent-field calculations and on-top density functionals are combined to describe both static and dynamic correlation. Here, we investigate how the MC-PDFT total energy and its components depend on the active space choice in the case of the H 2 and N 2 molecules. The active space dependence of the on-top pair density, the total density, the ratio of on-top pair density to half the square of the electron density, and the satisfaction of the virial theorem are also explored. We find that the density and on-top pair density do not change significantly with changes in the active space. However, the on-top ratio does change significantly with respect to active space change, and this affects the on-top energy. This study provides a foundation for designing on-top density functionals and automatizing the active space choice in MC-PDFT.

Trajectory data analyses for pedestrian space-time activity study.

PubMed

Qi, Feng; Du, Fei

2013-02-25

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

Youth activity spaces and daily exposure to tobacco outlets.

PubMed

Lipperman-Kreda, Sharon; Morrison, Christopher; Grube, Joel W; Gaidus, Andrew

2015-07-01

We explored whether exposure to tobacco outlets in youths' broader activity spaces differs from that obtained using traditional geographic measures of exposure to tobacco outlet within buffers around homes and schools. Youths completed an initial survey, daily text-prompted surveys, and carried GPS-enabled phones for one week. GPS locations were geocoded and activity spaces were constructed by joining sequential points. We calculated the number of tobacco outlets around these polylines and around homes and schools. Results suggest that activity spaces provide a more accurate measure of tobacco outlet exposures than traditional measures. Assessing tobacco outlet exposure within activity spaces may yield significant information to advance the field. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Distant Green Space on Physical Activity in Sydney, Australia.

PubMed

Chong, Shanley; Byun, Roy; Mazumdar, Soumya; Bauman, Adrian; Jalaludin, Bin

2017-01-01

The aim was to investigate the association between distant green space and physical activity modified by local green space. Information about physical activity, demographic and socioeconomic background at the individual level was extracted from the New South Wales Population Health Survey. The proportion of a postcode that was parkland was used as a proxy measure for access to parklands and was calculated for each individual. There was a significant relationship between distant green space and engaging in moderate-to-vigorous physical activity (MVPA) at least once a week. No significant relationship was found between adequate physical activity and distant green space. No significant relationships were found between adequate physical activity, engaging in MVPA, and local green space. However, if respondents lived in greater local green space (≥25%), there was a significant relationship between engaging in MVPA at least once a week and distance green space of ≥20%. This study highlights the important effect of distant green space on physical activity. Our findings also suggest that moderate size of local green space together with moderate size of distant green space are important levers for participation of physical activity.

Space activity and programs at SOFRADIR

NASA Astrophysics Data System (ADS)

Bouakka-Manesse, A.; Jamin, N.; Delannoy, A.; Fieque, B.; Leroy, C.; Pidancier, P.; Vial, L.; Chorier, P.; Péré-Laperne, N.

2016-09-01

SOFRADIR is one of the leading companies involved in the development and manufacturing of infrared detectors for space applications. As a matter of fact, SOFRADIR is involved in many space programs from visible up to VLWIR spectral ranges. These programs concern operational missions for earth imagery, meteorology and also scientific missions for universe exploration. One of the last space detectors available at SOFRADIR is a visible - SWIR detector named Next Generation Panchromatic Detector (NGP) which is well adapted for hyperspectral, imagery and spectroscopy applications. In parallel of this new space detector, numerous programs are currently running for different kind of missions: meteorology (MTG), Copernicus with the Sentinel detectors series, Metop-SG system (3MI), Mars exploration (Mamiss, etc.). In this paper, we present the last developments made for space activity and in particular the NGP detector. We will also present the space applications using this detector and show appropriateness of its use to answer space programs specifications, as for example those of Sentinel-5.

Space activity and programs at Sofradir

NASA Astrophysics Data System (ADS)

Bouakka-Manesse, A.; Jamin, N.; Delannoy, A.; Fièque, B.; Leroy, C.; Pidancier, P.; Vial, L.; Chorier, P.; Péré Laperne, N.

2016-10-01

SOFRADIR is one of the leading companies involved in the development and manufacturing of infrared detectors for space applications. As a matter of fact, SOFRADIR is involved in many space programs from visible up to VLWIR spectral ranges. These programs concern operational missions for earth imagery, meteorology and also scientific missions for universe exploration. One of the last space detectors available at SOFRADIR is a visible - SWIR detector named Next Generation Panchromatic Detector (NGP) which is well adapted for hyperspectral, imagery and spectroscopy applications. In parallel of this new space detector, numerous programs are currently running for different kind of missions: meteorology (MTG), Copernicus with the Sentinel detectors series, Metop-SG system (3MI), Mars exploration (Mamiss, etc….)… In this paper, we present the last developments made for space activity and in particular the NGP detector. We will also present the space applications using this detector and show appropriateness of its use to answer space programs specifications, as for example those of Sentinel-5.

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.

Activities in Science Related to Space.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

Contained are a collection of science activities based upon forty-six scientific concepts related to space science. These activities are designed for junior high school science, but a much wider grade level range of use is possible. The booklet is primarily intended for teacher use. Each series of concept-oriented activities is independent of the…

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

PubMed Central

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-κB in the nucleus of TNFα-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

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.

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.

Second-order perturbation theory with a density matrix renormalization group self-consistent field reference function: theory and application to the study of chromium dimer.

PubMed

Kurashige, Yuki; Yanai, Takeshi

2011-09-07

We present a second-order perturbation theory based on a density matrix renormalization group self-consistent field (DMRG-SCF) reference function. The method reproduces the solution of the complete active space with second-order perturbation theory (CASPT2) when the DMRG reference function is represented by a sufficiently large number of renormalized many-body basis, thereby being named DMRG-CASPT2 method. The DMRG-SCF is able to describe non-dynamical correlation with large active space that is insurmountable to the conventional CASSCF method, while the second-order perturbation theory provides an efficient description of dynamical correlation effects. The capability of our implementation is demonstrated for an application to the potential energy curve of the chromium dimer, which is one of the most demanding multireference systems that require best electronic structure treatment for non-dynamical and dynamical correlation as well as large basis sets. The DMRG-CASPT2/cc-pwCV5Z calculations were performed with a large (3d double-shell) active space consisting of 28 orbitals. Our approach using large-size DMRG reference addressed the problems of why the dissociation energy is largely overestimated by CASPT2 with the small active space consisting of 12 orbitals (3d4s), and also is oversensitive to the choice of the zeroth-order Hamiltonian. © 2011 American Institute of Physics

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.

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.

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

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.

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)…

Antiproliferation effect of imatinib mesylate on MCF7, T-47D tumorigenic and MCF 10A nontumorigenic breast cell lines via PDGFR-β, PDGF-BB, c-Kit and SCF genes

PubMed Central

Kadivar, Ali; Kamalidehghan, Behnam; Akbari Javar, Hamid; Karimi, Benyamin; Sedghi, Reihaneh; Noordin, Mohamed Ibrahim

2017-01-01

Recent cancer molecular therapies are targeting main functional molecules to control applicable process of cancer cells. Attractive targets are established by receptor tyrosine kinases, such as platelet-derived growth factor receptors (PDGFRs) and c-Kit as mostly irregular signaling, which is due to either over expression or mutation that is associated with tumorigenesis and cell proliferation. Imatinib mesylate is a selective inhibitor of receptor tyrosine kinase, including PDGFR-β and c-Kit. In this research, we studied how imatinib mesylate would exert effect on MCF7 and T-47D breast cancer and MCF 10A epithelial cell lines, the gene and protein expression of PDGFR-β, c-Kit and their relevant ligands platelet-derived growth factor (PDGF)-BB and stem cell factor (SCF). The MTS assay was conducted in therapeutic relevant concentration of 2–10 µM for 96, 120 and 144 h treatment. In addition, apoptosis induction and cytostatic activity of imatinib mesylate were investigated with the terminal deoxynucleotidyl transferase dUTP nick end labeling TUNEL and cell cycle assays, respectively, in a time-dependent manner. Comparative real-time PCR and Western blot analysis were conducted to evaluate the expression and regulation of imatinib target genes and proteins. Our finding revealed that imatinib mesylate antiproliferation effect, apoptosis induction and cytostatic activity were significantly higher in breast cancer cell lines compared to MCF 10A. This effect might be due to the expression of PDGFR-β, PDGF-BB, c-Kit and SCF, which was expressed by all examined cell lines, except the T-47D cell line which was not expressed c-Kit. However, examined gene and proteins expressed more in cancer cell lines. Therefore, imatinib mesylate was more effective on them. It is concluded that imatinib has at least two potential targets in both examined breast cancer cell lines and can be a promising drug for targeted therapy to treat breast cancer. PMID:28260860

Assessing Built Environment Walkability using Activity-Space Summary Measures.

PubMed

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

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.

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

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.

Deviations from idealised geometries part 3: approximately tetrahedral molecules of form MX 2Y 2 studied by SCF and MP2 calculations

NASA Astrophysics Data System (ADS)

Palmer, Michael H.

1997-03-01

The relatively minor deviations from true tetrahedral geometry for molecules of type MX 2Y 2 where M is tetravalent, and X, Y are either H, Me or halogen are discussed, in the light of ab initio calculations of equilibrium geometry with a large (triple zeta valence + polarisation) basis, at both the SCF and MP2 levels. The results are compared with known experimental structural and dipole moment data; in most cases a very close correlation with experiment is found, with slight improvements in the MP2 data. The study is coupled with a localised orbital study of relevance to Bent's Rule.

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

Friction and wear of single-crystal and polycrystalline maganese-zinc ferrite in contact with various metals

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Buckley, D. H.

1977-01-01

Sliding friction experiments were conducted with single-crystal (SCF) and hot-pressed polycrystalline (HPF) manganese-zinc ferrite in contact with various metals. Results indicate that the coefficients of friction for SCF and HPF are related to the relative chemical activity of those metals in high vacuum. The more active the metal, the higher the coefficient of friction. The coefficients of friction for both SCF and HPF were the same and much higher in vacuum than in argon at atmospheric pressure. All the metals tested transferred to the surface of both SCF and HPF in sliding. Both SCF and HPF exhibited cracking and fracture with sliding. Cracking in SCF is dependent on crystallographic characteristics. In HPF, cracking depends on the orientation of the individual crystallites.

Automated entry technologies for confined space work activities: A survey.

PubMed

Botti, Lucia; Ferrari, Emilio; Mora, Cristina

2017-04-01

Work in confined spaces poses a significant risk to workers and rescuers involved in the emergency response when an accident occurs. Despite several standards and regulations define the safety requirements for such activities, injuries, and fatalities still occur. Furthermore, the on-site inspections after accidents often reveal that both employers and employees fail to implement safe entry procedures. Removing the risk is possible by avoiding the worker entry, but many activities require the presence of the operator inside the confined space to perform manual tasks. The following study investigates the available technologies for hazardous confined space work activities, e.g., cleaning, inspecting, and maintenance tasks. The aim is to provide a systematic review of the automated solutions for high-risk activities in confined spaces, considering the non-man entry as the most effective confined space safety strategy. Second, this survey aims to provide suggestions for future research addressing the design of new technologies. The survey consists of about 60 papers concerning innovative technologies for confined space work activities. The document review shows that several solutions have been developed and automation can replace the workers for a limited number of hazardous tasks. Several activities still require the manual intervention due to the complex characteristics of confined spaces, e.g., to remove the remains of the automatic cleaning process from the bottom of a tank. The results show that available technologies require more flexibility to adapt to such occupational environments and further research is needed.

Does Activity Space Size Influence Physical Activity Levels of Adolescents? - A GPS study of an urban environment.

PubMed

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

2016-06-01

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. 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. In Fall 2012, 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). On school days, students accrued 68.2 min/day (95% CI 60.4-76.0) of MVPA. Daily activity spaces averaged 2.2 km 2 (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. School and school travel are important sources of PA in Vancouver adolescents, irrespective of activity space area covered.

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.

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.

Development of magnetostrictive active members for control of space structures

NASA Astrophysics Data System (ADS)

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

1992-08-01

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.

Critical issues related to registration of space objects and transparency of space activities

NASA Astrophysics Data System (ADS)

Jakhu, Ram S.; Jasani, Bhupendra; McDowell, Jonathan C.

2018-02-01

The main purpose of the 1975 Registration Convention is to achieve transparency in space activities and this objective is motivated by the belief that a mandatory registration system would assist in the identification of space objects launched into outer space. This would also consequently contribute to the application and development of international law governing the exploration and use of outer space. States Parties to the Convention furnish the required information to the United Nations' Register of Space Objects. However, the furnished information is often so general that it may not be as helpful in creating transparency as had been hoped by the drafters of the Convention. While registration of civil satellites has been furnished with some general details, till today, none of the Parties have described the objects as having military functions despite the fact that a large number of such objects do perform military functions as well. In some cases, the best they have done is to indicate that the space objects are for their defense establishments. Moreover, the number of registrations of space objects is declining. This paper addresses the challenges posed by the non-registration of space objects. Particularly, the paper provides some data about the registration and non-registration of satellites and the States that have and have not complied with their legal obligations. It also analyses the specific requirements of the Convention, the reasons for non-registration, new challenges posed by the registration of small satellites and the on-orbit transfer of satellites. Finally, the paper provides some recommendations on how to enhance the registration of space objects, on the monitoring of the implementation of the Registration Convention and consequently how to achieve maximum transparency in space activities.

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…

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

First-principles real-space study of electronic and optical excitations in rutile TiO 2 nanocrystals

DOE PAGES

Hung, Linda; Baishya, Kopinjol; Öğüt, Serdar

2014-10-17

We model rutile titanium dioxide nanocrystals (NCs) up to ~1.5 nm in size to study the effects of quantum confinement on their electronic and optical properties. Ionization potentials (IPs) and electron affinities (EAs) are obtained via the perturbative GW approximation (G 0W 0) and ΔSCF method for NCs up to 24 and 64 TiO 2 formula units, respectively. These demanding GW computations are made feasible by using a real-space framework that exploits quantum confinement to reduce the number of empty states needed in GW summations. Time-dependent density functional theory (TDDFT) is used to predict the optical properties of NCs upmore » to 64 TiO 2 units. For a NC containing only 2 TiO 2 units, the offsets of the IP and the EA from the corresponding bulk limits are of similar magnitude. However, as NC size increases, the EA is found to converge more slowly to the bulk limit than the IP. The EA values computed at the G 0W 0 and ΔSCF levels of theory are found to agree fairly well with each other, while the IPs computed with ΔSCF are consistently smaller than those computed with G 0W 0 by a roughly constant amount. TDDFT optical gaps exhibit weaker size dependence than GW quasiparticle gaps, and result in exciton binding energies on the order of eV. Finally, altering the dimensions of a fixed-size NC can change electronic and optical excitations up to several tenths of an eV. The largest NCs modeled are still quantum confined and do not yet have quasiparticle levels or optical gaps at bulk values. Nevertheless, we find that classical Mie-Gans theory can quite accurately reproduce the line shape of TDDFT absorption spectra, even for (anisotropic) TiO 2 NCs of subnanometer size.« less

First-principles real-space study of electronic and optical excitations in rutile TiO2 nanocrystals

NASA Astrophysics Data System (ADS)

Hung, Linda; Baishya, Kopinjol; Ã-ǧüt, Serdar

2014-10-01

We model rutile titanium dioxide nanocrystals (NCs) up to ˜1.5 nm in size to study the effects of quantum confinement on their electronic and optical properties. Ionization potentials (IPs) and electron affinities (EAs) are obtained via the perturbative GW approximation (G0W0) and ΔSCF method for NCs up to 24 and 64 TiO2 formula units, respectively. These demanding GW computations are made feasible by using a real-space framework that exploits quantum confinement to reduce the number of empty states needed in GW summations. Time-dependent density functional theory (TDDFT) is used to predict the optical properties of NCs up to 64 TiO2 units. For a NC containing only 2 TiO2 units, the offsets of the IP and the EA from the corresponding bulk limits are of similar magnitude. However, as NC size increases, the EA is found to converge more slowly to the bulk limit than the IP. The EA values computed at the G0W0 and ΔSCF levels of theory are found to agree fairly well with each other, while the IPs computed with ΔSCF are consistently smaller than those computed with G0W0 by a roughly constant amount. TDDFT optical gaps exhibit weaker size dependence than GW quasiparticle gaps, and result in exciton binding energies on the order of eV. Altering the dimensions of a fixed-size NC can change electronic and optical excitations up to several tenths of an eV. The largest NCs modeled are still quantum confined and do not yet have quasiparticle levels or optical gaps at bulk values. Nevertheless, we find that classical Mie-Gans theory can quite accurately reproduce the line shape of TDDFT absorption spectra, even for (anisotropic) TiO2 NCs of subnanometer size.

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.

Deviations from idealised geometries part 4: approximately tetrahedral molecules of form MX 2Y 2 studied by SCF and MP2 localised orbital calculations

NASA Astrophysics Data System (ADS)

Palmer, Michael H.

1997-03-01

Using the delocalised wavefunctions from Part 3, for a series of molecules of type MX 2Y 2 where M is tetravalent, and X, Y are either H, Me or halogen, with a triple-zeta plus polarisation basis and either SCF of MP2 methods, the wavefunctions were converted to localised orbitals by the Foster-Boys method. This enabled the LMO to be subject to population analysis for changes in hybridisation in the individual total density of the MX and MY bonds, and some quantitative discussion of the role of hybridisation in Bent's Rule.

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.

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

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.

On the bonding mechanism of CO to Pt(111) and its effect on the vibrational frequency of chemisorbed CO

NASA Astrophysics Data System (ADS)

Illas, F.; Zurita, S.; Márquez, A. M.; Rubio, J.

1997-04-01

The chemisorption of CO on the atop site of Pt(111) has been simulated by a Pt4 cluster model. Ab initio self consistent field (SCF) and complete active space self consistent field (CASSCF) cluster model wave functions have been obtained for the electronic ground state. Likewise, ab initio SCF wavefunctions have been obtained for two other electronic states. The optimum geometry and vibrational frequencies of chemisorbed CO are reported for the three states. The interaction energy and vibrational shift of chemisorbed CO, with respect to free gas phase CO, have been analyzed for the three electronic states. This analysis is carried out by means of the constrained space orbital variation (CSOV) method. In all cases the bond is found to be dominated by σ donation and π back-donation, known as Blyholder's mechanism. This mechanism is further supported by SCF calculations on a larger, Pt13, cluster model. For both clusters, the CSOV analysis of the vibrational frequency definitely shows that, contrary to previous recent studies, a major contribution to the experimentally observed vibrational shift comes from the π back-donation mechanism. However, we found that, contrary to common belief, σ donation also acts to lower the CO frequency and not to increase it. Physical reasons for such unexpected behaviour are given.

Highly multireferenced arynes studied with large active spaces using two-electron reduced density matrices.

PubMed

Greenman, Loren; Mazziotti, David A

2009-05-14

Using the active-space two-electron reduced density matrix (2-RDM) method, which scales polynomially with the size of the active space [G. Gidofalvi and D. A. Mazziotti, J. Chem. Phys. 129, 134108 (2008)], we were able to use active spaces as large as 24 electrons in 24 orbitals in computing the ground-state energies and properties of highly multireferenced arynes. Because the conventional complete-active-space self-consistent-field (CASSCF) method scales exponentially with the size of the active space, its application to arynes was mainly limited to active spaces of 12 electrons in 12 orbitals. For these smaller active spaces the active-space 2-RDM method accurately reproduces the results of CASSCF. However, we show that the larger active spaces are necessary for describing changes in energies and properties with aryne chain length such as the emergence of polyradical character. Furthermore, the addition of further electron correlation by multireference perturbation theory is demonstrated to be inadequate for removing the limitations of the smaller active spaces.

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.

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.

Using experienced activity spaces to measure foodscape exposure.

PubMed

Kestens, Yan; Lebel, Alexandre; Daniel, Mark; Thériault, Marius; Pampalon, Robert

2010-11-01

Researchers are increasingly interested in understanding how food environments influence eating behavior and weight-related health outcomes. Little is known about the dose-response relationship between foodscapes and behavior or weight, with measures of food exposure having mainly focused on fixed anchor points including residential neighborhoods, schools, or workplaces. Recent calls have been made to extend the consideration of environmental influences beyond local neighborhoods and also to shift away from place-based, to people-based, measures of exposure. This report presents analyses of novel activity-space measures of exposure to foodscapes, combining travel survey data with food store locations in Montreal and Quebec City, Canada. The resulting individual activity-space experienced foodscape exposure measures differ from traditional residential-based measures, and show variations by age and income levels. Furthermore, these activity-space exposure measures once modeled, can be used as predictors of health outcomes. Hence, travel surveys can be used to estimate environmental exposure for health survey participants. Copyright © 2010 Elsevier Ltd. All rights reserved.

Selection of active spaces for multiconfigurational wavefunctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, Sebastian; Boguslawski, Katharina; Reiher, Markus, E-mail: markus.reiher@phys.chem.ethz.ch

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 approximatemore » 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

Mouse Spermatozoa Contain a Nuclease that Is Activated by Pretreatment with EGTA and Subsequent Calcium Incubation

PubMed Central

Boaz, Segal M.; Dominguez, Kenneth; Shaman, Jeffrey A.; Ward, W. Steven

2009-01-01

We demonstrated that mouse spermatozoa cleave their DNA into ~50 kb loop-sized fragments with topoisomerase IIB when treated with MnCl2 and CaCl2 in a process we term sperm chromatin fragmentation (SCF). SCF can be reversed by EDTA. A nuclease then further degrades the DNA in a process we term sperm DNA degradation (SDD). MnCl2 alone could elicit this activity, but CaCl2 had no effect. Here, we demonstrate the existence of a nuclease in the vas deferens that can be activated by EGTA to digest the sperm DNA by SDD. Spermatozoa were extracted with salt and dithiothreitol to remove protamines and then incubated with EGTA. Next, the EGTA was removed and divalent cations were added. We found that Mn+2, Ca+2, or Zn+2 could each activate SDD in spermatozoa but Mg+2 could not. When the reaction was slowed by incubation on ice, EGTA pretreatment followed by incubation in Ca+2 elicited the reversible fragmentation of sperm DNA evident in SCF. When the reactions were then incubated at 37°C they progressed to the more complete degradation of DNA by SDD. EDTA could also be used to activate the nuclease, but required a higher concentration than EGTA. This EGTA-activatable nuclease activity was found in each fraction of the vas deferens plasma: in the spermatozoa, in the surrounding fluid, and in the insoluble components in the fluid. These results suggest that this sperm nuclease is regulated by a mechanism that is sensitive to EGTA, possibly by removing inhibition of a calcium binding protein. PMID:17879959

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.

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.

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.

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…

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.

On the uniqueness of the constrained space orbital variation (CSOV) technique

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.

1986-01-01

Several CSOV analyses are performed for the 1Sigma(+) state of NiCO, and it is shown that the importance of the CO sigma donation, Ni pi back donation, and interunit polarizations are virtually independent of the order of the CSOV steps, provided that the open-shell 3d sigma and 4s Ni orbitals are orthogonalized to the CO. This order of orthogonalization is consistent with the polarization of the Ni observed in the unconstrained SCF wavefunction. If instead the CO is orthogonalized to the open-shell Ni orbitals, the frozen orbital repulsion and entire CSOV analysis becomes unphysical. A comparison of the SCF and CAS SCF descriptions for the NiCO 1Sigma(+) state shows the importance of the s to d promotion and sd hybridization in reducing the repulsion and increasing the Ni to CO pi bonding. For LiF, CSOV analyses starting from both the neutral and ionic asymptotes show the bonding to be predominantly Li(+) - F(-). These examples show the uniqueness of the CSOV decomposition.

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.

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.

Communication: A difference density picture for the self-consistent field ansatz.

PubMed

Parrish, Robert M; Liu, Fang; Martínez, Todd J

2016-04-07

We formulate self-consistent field (SCF) theory in terms of an interaction picture where the working variable is the difference density matrix between the true system and a corresponding superposition of atomic densities. As the difference density matrix directly represents the electronic deformations inherent in chemical bonding, this "difference self-consistent field (dSCF)" picture provides a number of significant conceptual and computational advantages. We show that this allows for a stable and efficient dSCF iterative procedure with wholly single-precision Coulomb and exchange matrix builds. We also show that the dSCF iterative procedure can be performed with aggressive screening of the pair space. These approximations are tested and found to be accurate for systems with up to 1860 atoms and >10 000 basis functions, providing for immediate overall speedups of up to 70% in the heavily optimized TeraChem SCF implementation.

Communication: A difference density picture for the self-consistent field ansatz

NASA Astrophysics Data System (ADS)

Parrish, Robert M.; Liu, Fang; Martínez, Todd J.

2016-04-01

We formulate self-consistent field (SCF) theory in terms of an interaction picture where the working variable is the difference density matrix between the true system and a corresponding superposition of atomic densities. As the difference density matrix directly represents the electronic deformations inherent in chemical bonding, this "difference self-consistent field (dSCF)" picture provides a number of significant conceptual and computational advantages. We show that this allows for a stable and efficient dSCF iterative procedure with wholly single-precision Coulomb and exchange matrix builds. We also show that the dSCF iterative procedure can be performed with aggressive screening of the pair space. These approximations are tested and found to be accurate for systems with up to 1860 atoms and >10 000 basis functions, providing for immediate overall speedups of up to 70% in the heavily optimized TeraChem SCF implementation.

Automated Construction of Molecular Active Spaces from Atomic Valence Orbitals.

PubMed

Sayfutyarova, Elvira R; Sun, Qiming; Chan, Garnet Kin-Lic; Knizia, Gerald

2017-09-12

We introduce the atomic valence active space (AVAS), a simple and well-defined automated technique for constructing active orbital spaces for use in multiconfiguration and multireference (MR) electronic structure calculations. Concretely, the technique constructs active molecular orbitals capable of describing all relevant electronic configurations emerging from a targeted set of atomic valence orbitals (e.g., the metal d orbitals in a coordination complex). This is achieved via a linear transformation of the occupied and unoccupied orbital spaces from an easily obtainable single-reference wave function (such as from a Hartree-Fock or Kohn-Sham calculations) based on projectors to targeted atomic valence orbitals. We discuss the premises, theory, and implementation of the idea, and several of its variations are tested. To investigate the performance and accuracy, we calculate the excitation energies for various transition-metal complexes in typical application scenarios. Additionally, we follow the homolytic bond breaking process of a Fenton reaction along its reaction coordinate. While the described AVAS technique is not a universal solution to the active space problem, its premises are fulfilled in many application scenarios of transition-metal chemistry and bond dissociation processes. In these cases the technique makes MR calculations easier to execute, easier to reproduce by any user, and simplifies the determination of the appropriate size of the active space required for accurate results.

Exploring Association between Morphology of Tree Planting and User Activities in Urban Public Space; An opportunity of Urban Public Space Revitalisation

NASA Astrophysics Data System (ADS)

Shen, Qi; Liu, Yan

2018-03-01

This paper discusses the association between the morphology of tree planting in urban riverside brown field and user activities. With the growth of popularity, the revitalisation of urban public space is also promising. This research used drone photography and mapping to systematically surveys sample sites. An original observation study of user activities proceed in four sample public spaces in Sheffield. The study results found there are huge popularity and duration difference of user activities between various tree planting morphologies and typologies. The public space with lawn and rounded by mature trees attracted most users with the most activity types; the neat and silent public space is the favourite choice of lunch and reading, meanwhile it got the longest activity duration; but the space with sparse morphology and small trees are more likely be forgotten and abandoned. This finding offered a great opportunity for urban public space revitalisation in post-industrial cities.

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

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.

Creating Inclusive Physical Activity Spaces: The Case of Body-Positive Yoga.

PubMed

Pickett, Andrew C; Cunningham, George B

2017-09-01

Within the modern cultural climate, those in larger bodies face high levels of weight stigma, particularly in sport and physical activity spaces, which serves as a strong barrier to their participation. However, given the strong link between physical activity and general health and well-being for participants, it is important to explore strategies that encourage participation of these individuals. Thus, the current research examined strategies that physical activity instructors use to develop inclusive exercise spaces for all body sizes. This study employed a series of semistructured qualitative interviews (n = 9) with instructors of body-inclusive yoga classes to explore the ways in which they encourage participation for those in larger bodies. Emergent themes from the current study suggested support for 6 factors for creating body-inclusive physical activity spaces: authentic leadership, a culture of inclusion, a focus on health, inclusive language, leader social activism, and a sense of community. This study revealed that leaders must intentionally cultivate inclusion in their spaces to encourage those in nonconforming bodies to participate. These findings have important health and management implications for the sport and physical activity context and provide a basic outline of practical strategies that practitioners can use to foster inclusion in their spaces.

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.

All 17 S-locus F-box proteins of the S2 - and S3 -haplotypes of Petunia inflata are assembled into similar SCF complexes with a specific function in self-incompatibility.

PubMed

Li, Shu; Williams, Justin S; Sun, Penglin; Kao, Teh-Hui

2016-09-01

The collaborative non-self-recognition model for S-RNase-based self-incompatibility predicts that multiple S-locus F-box proteins (SLFs) produced by pollen of a given S-haplotype collectively mediate ubiquitination and degradation of all non-self S-RNases, but not self S-RNases, in the pollen tube, thereby resulting in cross-compatible pollination but self-incompatible pollination. We had previously used pollen extracts containing GFP-fused S2 -SLF1 (SLF1 with an S2 -haplotype) of Petunia inflata for co-immunoprecipitation (Co-IP) and mass spectrometry (MS), and identified PiCUL1-P (a pollen-specific Cullin1), PiSSK1 (a pollen-specific Skp1-like protein) and PiRBX1 (a conventional Rbx1) as components of the SCF(S) (2-) (SLF) (1) complex. Using pollen extracts containing PiSSK1:FLAG:GFP for Co-IP/MS, we identified two additional SLFs (SLF4 and SLF13) that were assembled into SCF(SLF) complexes. As 17 SLF genes (SLF1 to SLF17) have been identified in S2 and S3 pollen, here we examined whether all 17 SLFs are assembled into similar complexes and, if so, whether these complexes are unique to SLFs. We modified the previous Co-IP/MS procedure, including the addition of style extracts from four different S-genotypes to pollen extracts containing PiSSK1:FLAG:GFP, to perform four separate experiments. The results taken together show that all 17 SLFs and an SLF-like protein, SLFLike1 (encoded by an S-locus-linked gene), co-immunoprecipitated with PiSSK1:FLAG:GFP. Moreover, of the 179 other F-box proteins predicted by S2 and S3 pollen transcriptomes, only a pair with 94.9% identity and another pair with 99.7% identity co-immunoprecipitated with PiSSK1:FLAG:GFP. These results suggest that SCF(SLF) complexes have evolved specifically to function in self-incompatibility. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

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.

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.

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.

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.

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.

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.

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.

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.

Passive and Active Control of Space Structures (PACOSS)

NASA Astrophysics Data System (ADS)

Morosow, G.; Harcrow, H.; Rogers, L.

1985-04-01

Passive and Active Control of Space Structures (PACOSS) is a five-year program designed to investigate highly damped structures in conjunction with active control systems, and in particular to develop technology that integrates passive damping and active control to achieve precise pointing control. Major areas of research include metal matrix composites; viscoelastic materials; damping devices; dynamic test article design, fabrication and testing; and active damping.

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.

An ab initio study on the four electronically lowest-lying states of CH 2 using the state-averaged complete active space second-order configuration interaction method

NASA Astrophysics Data System (ADS)

Yamaguchi, Yukio; Schaefer, Henry F., III

1997-12-01

Four electronically lowest-lying ( X˜ 3B 1, ã 1A 1, b˜ 1B 1, and c˜ 1A 1) states of CH 2 have been investigated systematically using ab initio electronic structure theory. Complete active space (CAS) self-consistent-field (SCF) second-order configuration interaction (SOCI) and state-averaged (SA) CASSCF-SOCI levels of theory have been employed. The CASSCF reference wave function was constructed by minimizing the total energy of a specified state, while the SACASSCF reference wave function was obtained by minimizing the equally weighted total energy of the four ( X˜ 3B 1, ã 1A 1, b˜ 1B 1, and c˜ 1A 1) states. The third excited state ( c˜ 1A 1 or 2 1A 1) is of particular theoretical interest because it is represented by the second root of CASSCF and SOCI Hamiltonian matrices. Theoretical treatments of states not the lowest of their symmetry require special attention due to their tendency of variational collapse to the lower-lying state(s). For these four lowest-lying states total energies and physical properties including dipole moments, harmonic vibrational frequencies, and associated infrared (IR) intensities were determined and compared with the results from the configuration interaction with single and double excitations (CISD) method and available experimental values. The CASSCF-SOCI method should provide the most reliable energetics and physical properties in the present study owing to its fully variational nature in the molecular orbital (MO) and CI spaces for a given state. It is demonstrated that the SACASSCF-SOCI wave functions produce results which are quite consistent with those from the CASSCF-SOCI method. Thus significantly increased application of the SACASSCF-SOCI method to the excited states of a wide variety of molecular systems is expected.

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

Three-dimensional carbon fibers and method and apparatus for their production

DOEpatents

Muradov, Nazim Z [Melbourne, FL

2012-02-21

This invention relates to novel three-dimensional (3D) carbon fibers which are original (or primary) carbon fibers (OCF) with secondary carbon filaments (SCF) grown thereon, and, if desired, tertiary carbon filaments (TCF) are grown from the surface of SCF forming a filamentous carbon network with high surface area. The methods and apparatus are provided for growing SCF on the OCF by thermal decomposition of carbonaceous gases (CG) over the hot surface of the OCF without use of metal-based catalysts. The thickness and length of SCF can be controlled by varying operational conditions of the process, e.g., the nature of CG, temperature, residence time, etc. The optional activation step enables one to produce 3D activated carbon fibers with high surface area. The method and apparatus are provided for growing TCF on the SCF by thermal decomposition of carbonaceous gases over the hot surface of the SCF using metal catalyst particles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parrish, Robert M.; Liu, Fang; Martínez, Todd J., E-mail: toddjmartinez@gmail.com

We formulate self-consistent field (SCF) theory in terms of an interaction picture where the working variable is the difference density matrix between the true system and a corresponding superposition of atomic densities. As the difference density matrix directly represents the electronic deformations inherent in chemical bonding, this “difference self-consistent field (dSCF)” picture provides a number of significant conceptual and computational advantages. We show that this allows for a stable and efficient dSCF iterative procedure with wholly single-precision Coulomb and exchange matrix builds. We also show that the dSCF iterative procedure can be performed with aggressive screening of the pair space.more » These approximations are tested and found to be accurate for systems with up to 1860 atoms and >10 000 basis functions, providing for immediate overall speedups of up to 70% in the heavily optimized TERACHEM SCF implementation.« less

Last results of MADRAS, a space active optics demonstrator

NASA Astrophysics Data System (ADS)

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

2017-11-01

The goal of the MADRAS project (Mirror Active, Deformable and Regulated for Applications in Space) is to highlight the interest of Active Optics for the next generation of space telescope and instrumentation. Wave-front errors in future space telescopes will mainly come from thermal dilatation and zero gravity, inducing large lightweight primary mirrors deformation. To compensate for these effects, a 24 actuators, 100 mm diameter deformable mirror has been designed to be inserted in a pupil relay. Within the project, such a system has been optimized, integrated and experimentally characterized. The system is designed considering wave-front errors expected in 3m-class primary mirrors, and taking into account space constraints such as compactness, low weight, low power consumption and mechanical strength. Finite Element Analysis allowed an optimization of the system in order to reach a precision of correction better than 10 nm rms. A dedicated test-bed has been designed to fully characterize the integrated mirror performance in representative conditions. The test set up is made of three main parts: a telescope aberrations generator, a correction loop with the MADRAS mirror and a Shack-Hartman wave-front sensor, and PSF imaging. In addition, Fizeau interferometry monitors the optical surface shape. We have developed and characterized an active optics system with a limited number of actuators and a design fitting space requirements. All the conducted tests tend to demonstrate the efficiency of such a system for a real-time, in situ wave-front. It would allow a significant improvement for future space telescopes optical performance while relaxing the specifications on the others components.

UV-B Radiation Induces Macrophage Migration Inhibitory Factor–Mediated Melanogenesis through Activation of Protease-Activated Receptor-2 and Stem Cell Factor in Keratinocytes

PubMed Central

Enomoto, Akiko; Yoshihisa, Yoko; Yamakoshi, Takako; Ur Rehman, Mati; Norisugi, Osamu; Hara, Hiroshi; Matsunaga, Kenji; Makino, Teruhiko; Nishihira, Jun; Shimizu, Tadamichi

2011-01-01

UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation. PMID:21281800

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.

Routine Activities and Criminal Victimization: The Significance of Gendered Spaces.

PubMed

Savard, Dennis M; Kelley, Thomas M; Merolla, David M

2017-07-01

Gender is arguably the most prominent correlate of criminal victimization. Few studies, however, examine gender-specific dynamics that might help advance criminology's understanding of the persistent gender gap in criminal victimization. We attempt to help fill this research void by examining data from the 2012 National Incident-Based Reporting System (NIBRS) through the lens of routine activity theory to investigate the relationship between "gendered spaces" and criminal victimization. We propose that gendered spaces constructed by people's routine activities may increase their exposure to motivated offenders, which in turn may increase their risk of victimization. Our findings appear to support our proposition and to shed new light on the nature of the victimization gender gap. The results showed that females were significantly more likely than males to be victimized at each of the three "feminine gendered spaces" (i.e., bank, shopping center, and grocery store). However, the relationship between gendered space and criminal victimization varied by crime type. Females were significantly more likely than males to be robbed at each of the three feminine gendered spaces. For sexual assault and aggravated assault, females were significantly more likely than males to be victimized at a "masculine gendered space" (i.e., bar/nightclub). For simple assault, females were significantly less likely than males to be victimized at two of the three feminine gendered spaces (i.e., bank and shopping center). Our findings appear to highlight the importance of gendered spaces in helping explain the gender gap in criminal victimization and suggest that future researchers should investigate how other gendered spaces formed by people's routine activities affect their risk of victimization.

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.

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 Exploration...

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 Exploration...

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. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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.

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.

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.

Decoupling the Functional Pleiotropy of Stem Cell Factor by Tuning c-Kit Signaling

PubMed Central

Ho, Chia Chi M.; Chhabra, Akanksha; Starkl, Philipp; Schnorr, Peter-John; Wilmes, Stephan; Moraga, Ignacio; Kwon, Hye-Sook; Gaudenzio, Nicolas; Sibilano, Riccardo; Wehrman, Tom S.; Gakovic, Milica; Sockolosky, Jonathan T.; Tiffany, Matthew R.; Ring, Aaron M.; Piehler, Jacob; Weissman, Irving L.; Galli, Stephen J.; Shizuru, Judith A.; Garcia, K. Christopher

2017-01-01

SUMMARY Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion, but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems. PMID:28283060

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.

Moving through Life-Space Areas and Objectively Measured Physical Activity of Older People.

PubMed

Portegijs, Erja; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2015-01-01

Physical activity-an important determinant of health and function in old age-may vary according to the life-space area reached. Our aim was to study how moving through greater life-space areas is associated with greater physical activity of community-dwelling older people. The association between objectively measured physical activity and life-space area reached on different days by the same individual was studied using one-week longitudinal data, to provide insight in causal relationships. One-week surveillance of objectively assessed physical activity of community-dwelling 70-90-year-old people in central Finland from the "Life-space mobility in old age" cohort substudy (N = 174). In spring 2012, participants wore an accelerometer for 7 days and completed a daily diary including the largest life-space area reached (inside home, outside home, neighborhood, town, and beyond town). The daily step count, and the time in moderate (incl. walking) and low activity and sedentary behavior were assessed. Differences in physical activity between days on which different life-space areas were reached were tested using Generalized Estimation Equation models (within-group comparison). Participants' mean age was 80.4±4.2 years and 63.5% were female. Participants had higher average step counts (p < .001) and greater moderate and low activity time (p < .001) on days when greater life-space areas were reached, from the home to the town area. Only low activity time continued to increase when moving beyond the town. Community-dwelling older people were more physically active on days when they moved through greater life-space areas. While it is unknown whether physical activity was a motivator to leave the home, intervention studies are needed to determine whether facilitation of daily outdoor mobility, regardless of the purpose, may be beneficial in terms of promoting physical activity.

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

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

Anticipatory Postural Activity During Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Layne, C. S.; Mulavara, A. P.; McDonald, P. V.; Pruett, C. J.; Koslovskaya, B.; Bloomberg, J. J.

1999-01-01

Somatosensory input has been used to modify motor output in many contexts. During space flight, the use of the lower limb musculature is much less than during activities in 1g. Consequently the neuromuscular activity of the legs is also reduced during space flight. This decrease in muscle activity contributes to muscle atrophy. Furthermore, adaptations to weightlessness contribute to posture and locomotion problems upon the return to Earth. Providing techniques to counter the negative effects of weightlessness on the neuromuscular system is an important goal, particularly during a long-duration mission. Previous work by our group has shown that lower limb neuromuscular activation that normally precedes arm movements in 1g is absent or greatly reduced during similar movements made while freefloating. However, preliminary evidence indicates that applying pressure to the feet results in enhanced neuromuscular activation during rapid arm movements performed while freefloating. This finding suggests that sensory input can be used to "drive" the motor system to increase neuromuscular functioning throughout a mission. The purpose of this investigation was to quantify the increase in neuromuscular activation resulting from the application of pressure to the feet.

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)…

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.

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.

Task-discriminative space-by-time factorization of muscle activity.

PubMed

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.

Space-Time Dependent Transport, Activation, and Dose Rates for Radioactivated Fluids.

NASA Astrophysics Data System (ADS)

Gavazza, Sergio

Two methods are developed to calculate the space - and time-dependent mass transport of radionuclides, their production and decay, and the associated dose rates generated from the radioactivated fluids flowing through pipes. The work couples space- and time-dependent phenomena, treated as only space- or time-dependent in the open literature. The transport and activation methodology (TAM) is used to numerically calculate space- and time-dependent transport and activation of radionuclides in fluids flowing through pipes exposed to radiation fields, and volumetric radioactive sources created by radionuclide motions. The computer program Radionuclide Activation and Transport in Pipe (RNATPA1) performs the numerical calculations required in TAM. The gamma ray dose methodology (GAM) is used to numerically calculate space- and time-dependent gamma ray dose equivalent rates from the volumetric radioactive sources determined by TAM. The computer program Gamma Ray Dose Equivalent Rate (GRDOSER) performs the numerical calculations required in GAM. The scope of conditions considered by TAM and GAM herein include (a) laminar flow in straight pipe, (b)recirculating flow schemes, (c) time-independent fluid velocity distributions, (d) space-dependent monoenergetic neutron flux distribution, (e) space- and time-dependent activation process of a single parent nuclide and transport and decay of a single daughter radionuclide, and (f) assessment of space- and time-dependent gamma ray dose rates, outside the pipe, generated by the space- and time-dependent source term distributions inside of it. The methodologies, however, can be easily extended to include all the situations of interest for solving the phenomena addressed in this dissertation. A comparison is made from results obtained by the described calculational procedures with analytical expressions. The physics of the problems addressed by the new technique and the increased accuracy versus non -space and time-dependent methods

The Effects of Hematopoietic Growth Factors on Neurite Outgrowth

PubMed Central

Su, Ye; Cui, Lili; Piao, Chunshu; Li, Bin; Zhao, Li-Ru

2013-01-01

Stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) are initially discovered as the essential hematopoietic growth factors regulating bone marrow stem cell proliferation and differentiation, and SCF in combination with G-CSF (SCF+G-CSF) has synergistic effects on bone marrow stem cell mobilization. In this study we have determined the effect of SCF and G-CSF on neurite outgrowth in rat cortical neurons. Using molecular and cellular biology and live cell imaging approaches, we have revealed that receptors for SCF and G-CSF are expressed on the growth core of cortical neurons, and that SCF+G-CSF synergistically enhances neurite extension through PI3K/AKT and NFκB signaling pathways. Moreover, SCF+G-CSF induces much greater NFκB activation, NFκB transcriptional binding and brain-derived neurotrophic factor (BDNF) production than SCF or G-CSF alone. In addition, we have also observed that BDNF, the target gene of NFκB, is required for SCF+G-CSF-induced neurite outgrowth. These data suggest that SCF+G-CSF has synergistic effects to promote neurite growth. This study provides new insights into the contribution of hematopoietic growth factors in neuronal plasticity. PMID:24116056

Large-scale purification and characterization of recombinant human stem cell factor in Escherichia coli.

PubMed

Chen, Liang-Hua; Cai, Feng; Zhang, Dan-Ju; Zhang, Li; Zhu, Peng; Gao, Shun

2017-07-01

The pharmacological importance of recombinant human stem cell factor (rhSCF) has increased the demand to establish effective and large-scale production and purification processes. A good source of bioactive recombinant protein with capability of being scaled-up without losing activity has always been a challenge. The objectives of the study were the rapid and efficient pilot-scale expression and purification of rhSCF. The gene encoding stem cell factor (SCF) was cloned into pBV220 and transformed into Escherichia coli. The recombinant SCF was expressed and isolated using a procedure consisting of isolation of inclusion bodies (IBs), denaturation, and refolding followed by chromatographic steps toward purification. The yield of rhSCF reached 835.6 g/20 L, and the expression levels of rhSCF were about 33.9% of the total E. coli protein content. rhSCF was purified by isolation of IBs, denaturation, and refolding, followed by SP-Sepharose chromatography, Source 30 reversed-phase chromatography, and Q-Sepharose chromatography. This procedure was developed to isolate 5.5 g of rhSCF (99.5% purity) with specific activity at 0.96 × 10 6  IU/mg, endotoxin levels of pyrogen at 1.0 EU/mg, and bacterial DNA at 10 ng/mg. Pilot-scale fermentations and purifications were set up for the production of rhSCF that can be upscaled for industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

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.

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.

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.;

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

Code of Federal Regulations, 2011 CFR

2011-10-01

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

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.

Identification of mutations in the coding sequence of the proto-oncogene c-kit in a human mast cell leukemia cell line causing ligand-independent activation of c-kit product.

PubMed Central

Furitsu, T; Tsujimura, T; Tono, T; Ikeda, H; Kitayama, H; Koshimizu, U; Sugahara, H; Butterfield, J H; Ashman, L K; Kanayama, Y

1993-01-01

The c-kit proto-oncogene encodes a receptor tyrosine kinase. Binding of c-kit ligand, stem cell factor (SCF) to c-kit receptor (c-kitR) is known to activate c-kitR tyrosine kinase, thereby leading to autophosphorylation of c-kitR on tyrosine and to association of c-kitR with substrates such as phosphatidylinositol 3-kinase (PI3K). In a human mast cell leukemia cell line HMC-1, c-kitR was found to be constitutively phosphorylated on tyrosine, activated, and associated with PI3K without the addition of SCF. The expression of SCF mRNA transcript in HMC-1 cells was not detectable by means of PCR after reverse transcription (RT-PCR) analysis, suggesting that the constitutive activation of c-kitR was ligand independent. Sequencing of whole coding region of c-kit cDNA revealed that c-kit genes of HMC-1 cells were composed of a normal, wild-type allele and a mutant allele with two point mutations resulting in intracellular amino acid substitutions of Gly-560 for Val and Val-816 for Asp. Amino acid sequences in the regions of the two mutations are completely conserved in all of mouse, rat, and human c-kit. In order to determine the causal role of these mutations in the constitutive activation, murine c-kit mutants encoding Gly-559 and/or Val-814, corresponding to human Gly-560 and/or Val-816, were constructed by site-directed mutagenesis and expressed in a human embryonic kidney cell line, 293T cells. In the transfected cells, both c-kitR (Gly-559, Val-814) and c-kitR (Val-814) were abundantly phosphorylated on tyrosine and activated in immune complex kinase reaction in the absence of SCF, whereas tyrosine phosphorylation and activation of c-kitR (Gly-559) or wild-type c-kitR was modest or little, respectively. These results suggest that conversion of Asp-816 to Val in human c-kitR may be an activating mutation and responsible for the constitutive activation of c-kitR in HMC-1 cells. Images PMID:7691885

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.

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

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.

The ordering of symmetric diblock copolymers: A comparison of self-consistent-field and density functional approaches

NASA Astrophysics Data System (ADS)

Nath, Shyamal K.; McCoy, John D.; Curro, John G.; Saunders, Randall S.

1997-02-01

Polymer reference interaction site model (PRISM) based density functional (DF) theory is used to evaluate the structure and thermodynamics of structurally symmetric, freely jointed, diblock chains with 0.50 volume fraction. These results are compared to the results of self-consistent-field (SCF) theory. Agreement between the predictions of the SCF and DF theories is found for the lamella spacing well above the order-disorder transition (ODT) and for the qualitative behavior of the interfacial thickness as a function of both chain length and Flory-Huggins χ parameter. Disagreement is found for the magnitude of the interfacial thickness where DF theory indicates that the thickness is 1.7±0.2 times larger than that predicted by SCF theory. It appears that behavior on the monomer length scale is sensitive to system specific details which are neglected by SCF theory.

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.

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.

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.

CRISPR/Cas9-mediated knockout of PiSSK1 reveals essential role of S-locus F-box protein-containing SCF complexes in recognition of non-self S-RNases during cross-compatible pollination in self-incompatible Petunia inflata.

PubMed

Sun, Linhan; Kao, Teh-Hui

2018-06-01

Function of Petunia PiSSK1. Self-incompatibility (SI), an inbreeding-preventing mechanism, is regulated in Petunia inflata by the polymorphic S-locus, which houses multiple pollen-specific S-locus F-box (SLF) genes and a single pistil-specific S-RNase gene. S 2 -haplotype and S 3 -haplotype possess the same 17 polymorphic SLF genes (named SLF1 to SLF17), and each SLF protein produced in pollen is assembled into an SCF (Skp1-Cullin1-F-box) E3 ubiquitin ligase complex. A complete suite of SLF proteins is thought to collectively interact with all non-self S-RNases to mediate their ubiquitination and degradation by the 26S proteasome, allowing cross-compatible pollination. For each SCF SLF complex, the Cullin1 subunit (named PiCUL1-P) and Skp1 subunit (named PiSSK1), like the F-box protein subunits (SLFs), are pollen-specific, raising the possibility that they also evolved specifically to function in SI. Here we used CRISPR/Cas9-meditated genome editing to generate frame-shift indel mutations in PiSSK1 and examined the SI behavior of a T 0 plant (S 2 S 3 ) with biallelic mutations in the pollen genome and two progeny plants (S 2 S 2 ) each homozygous for one of the indel alleles and not carrying the Cas9-containing T-DNA. Their pollen was completely incompatible with pistils of seven otherwise-compatible S-genotypes, but fully compatible with pistils of an S 3 S 3 transgenic plant in which production of S 3 -RNase was completely suppressed by an antisense S 3 -RNase gene, and with pistils of immature flower buds, which produce little S-RNase. These results suggest that PiSSK1 specifically functions in SI and support the hypothesis that SLF-containing SCF complexes are essential for compatible pollination.

Neuroprotection by stem cell factor in rat cortical neurons involves AKT and NFkappaB.

PubMed

Dhandapani, Krishnan M; Wade, F Marlene; Wakade, Chandramohan; Mahesh, Virendra B; Brann, Darrell W

2005-10-01

Stem cell factor (SCF) is a highly expressed cytokine in the central nervous system. In the present study, we demonstrate a neuroprotective role for SCF and its tyrosine kinase receptor, c-kit, against camptothecin-induced apoptosis and glutamate excitotoxicity in rat cortical neurons. This protection was blocked by pharmacological or molecular inhibition of either the MEK/ERK or PI3K/Akt signaling pathways. The importance of these pathways was further confirmed by the activation of both ERK, in a MEK-dependent manner, and Akt, via PI3K. Activation of Akt increased the binding of the p50 and p65 subunits of NFkappaB, which was also important for neuroprotection. Akt inhibition prevented NFkappaB binding, suggesting a role for Akt in SCF-induced NFkappaB. Pharmacological inhibition of NFkappaB or dominant negative IkappaB also prevented neuroprotection by SCF. SCF up-regulated the anti-apoptotic genes, bcl-2 and bcl-xL in an NFkappaB-dependent manner. Together, these findings demonstrate a neuroprotective role for SCF in cortical neurons, an effect that was mediated by Akt and ERK, as well as NFkappaB-mediated gene transcription. SCF represents a novel therapeutic target in the treatment of neurodegenerative disease.

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

UV-B radiation induces macrophage migration inhibitory factor-mediated melanogenesis through activation of protease-activated receptor-2 and stem cell factor in keratinocytes.

PubMed

Enomoto, Akiko; Yoshihisa, Yoko; Yamakoshi, Takako; Ur Rehman, Mati; Norisugi, Osamu; Hara, Hiroshi; Matsunaga, Kenji; Makino, Teruhiko; Nishihira, Jun; Shimizu, Tadamichi

2011-02-01

UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

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.

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.

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.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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.

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.

Maritime Activities: Requirements for Improving Space Based Solutions

NASA Astrophysics Data System (ADS)

Cragnolini, A.; Miguel-Lago, M.

2005-03-01

Maritime initiatives cannot be pursued only within their own perimeter. Sector endeavours and the policies which rule over them have wide range implications and several links with other sectors of activity. A well- balanced relationship of sea exploitation, maritime transportation, environmental protection and security ruled by national or international laws, will be a main issue for the future of all kind of maritime activities. Scientific research and technology development, along with enlightened and appropriate institutional regulations are relevant to ensure maritime sustainability.The use of satellite technology for monitoring international agreements should have a close co- ordination and be based on institutional consensus. Frequently, rules and new regulations set by policy makers are not demanding enough due to lack of knowledge about the possibilities offered by available technologies.Law enforcement actions could bring space technology new opportunities to offer solutions for monitoring and verification. Operators should aim at offering space data in a more operational and user-friendly way, providing them with useful and timely information.This paper will analyse the contribution of satellite technology to deal with the specificity of maritime sector, stressing the conditions for both an adequate technology improvement and an effective policy implementation.After analysing the links between maritime activities, space technologies and the institutional environment, the paper identifies some boundary conditions of the future developments. Conclusions are basically a check list for improving the present situation, while a road map is suggested as a matter of a way to proceed.

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.

Marshall Space Flight Center battery activity

NASA Technical Reports Server (NTRS)

Lowery, Eric

1993-01-01

The topics covered are presented in viewgraph form and include a flight program history and in-house activities. Some of the in-house activities addressed include secondary battery/cell testing and Hubble Space Telescope Test data updates involving the NiCd type 40 test - battery 1 and 2, the NiCd type 41 test battery, the general electric battery, the NiCd six-battery system, the six four-cell packs, fourteen-cell pack, three four-cell packs, the NiH2 six-battery system, and the flight spare battery. A general test data update is also presented for the twelve-cell pack, the four four-cell packs, the reconditioning test, and planned Ni-MH testing.

Construction of CASCI-type wave functions for very large active spaces.

PubMed

Boguslawski, Katharina; Marti, Konrad H; Reiher, Markus

2011-06-14

We present a procedure to construct a configuration-interaction expansion containing arbitrary excitations from an underlying full-configuration-interaction-type wave function defined for a very large active space. Our procedure is based on the density-matrix renormalization group (DMRG) algorithm that provides the necessary information in terms of the eigenstates of the reduced density matrices to calculate the coefficient of any basis state in the many-particle Hilbert space. Since the dimension of the Hilbert space scales binomially with the size of the active space, a sophisticated Monte Carlo sampling routine is employed. This sampling algorithm can also construct such configuration-interaction-type wave functions from any other type of tensor network states. The configuration-interaction information obtained serves several purposes. It yields a qualitatively correct description of the molecule's electronic structure, it allows us to analyze DMRG wave functions converged for the same molecular system but with different parameter sets (e.g., different numbers of active-system (block) states), and it can be considered a balanced reference for the application of a subsequent standard multi-reference configuration-interaction method.

Successive and discrete spaced conditioning in active avoidance learning in young and aged zebrafish.

PubMed

Yang, Peng; Kajiwara, Riki; Tonoki, Ayako; Itoh, Motoyuki

2018-05-01

We designed an automated device to study active avoidance learning abilities of zebrafish. Open source tools were used for the device control, statistical computing, and graphic outputs of data. Using the system, we developed active avoidance tests to examine the effects of trial spacing and aging on learning. Seven-month-old fish showed stronger avoidance behavior as measured by color preference index with discrete spaced training as compared to successive spaced training. Fifteen-month-old fish showed a similar trend, but with reduced cognitive abilities compared with 7-month-old fish. Further, in 7-month-old fish, an increase in learning ability during trials was observed with discrete, but not successive, spaced training. In contrast, 15-month-old fish did not show increase in learning ability during trials. Therefore, these data suggest that discrete spacing is more effective for learning than successive spacing, with the zebrafish active avoidance paradigm, and that the time course analysis of active avoidance using discrete spaced training is useful to detect age-related learning impairment. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

The places parents go: understanding the breadth, scope, and experiences of activity spaces for parents.

PubMed

Wolf, Jennifer Price; Freisthler, Bridget; Kepple, Nancy Jo; Chávez, Raúl

2017-04-01

Neighborhood environments are related to parenting behaviors, which in turn have a life-long effect on children's health and well-being. Activity spaces, which measure individual routine patterns of movement, may be helpful in assessing how physical and social environments shape parenting. In this study we use qualitative data and GIS mapping from 4 California cities to examine parental activity spaces. Parents described a number of factors that shape their activity spaces including caregiving status, the age of their children, and income. Parental activity spaces also varied between times (weekends vs. weekdays) and places (adult-only vs. child-specific places). Knowing how to best capture and study parental activity spaces could identify mechanisms by which environmental factors influence parenting behaviors and child health.

searchSCF: Using MongoDB to Enable Richer Searches of Locally Hosted Science Data Repositories

NASA Astrophysics Data System (ADS)

Knosp, B.

2016-12-01

Science teams today are in the unusual position of almost having too much data available to them. Modern sensors and models are capable of outputting terabytes of data per day, which can make it difficult to find specific subsets of data. The sheer size of files can also make it time consuming to retrieve this big data from national data archive centers. Thus, many science teams choose to store what data they can on their local systems, but they are not always equipped with tools to help them intelligently organize and search their data. In its local data repository, the Aura Microwave Limb Sounder (MLS) science team at NASA's Jet Propulsion Laboratory has collected over 300TB of atmospheric science data from 71 missions/models that aid in validation, algorithm development, and research activities. When the project began, the team developed a MySQL database to aid in data queries, but this database was only designed to keep track of MLS and a few ancillary data sets, leving much of the data uncatalogued. The team has also seen database query time rise over the life of the mission. Even though the MLS science team's data holdings are not the size of a national data center's, team members still need tools to help them discover and utilize the data that they have on-hand. Over the past year, members of the science team have been looking for solutions to (1) store information on all the data sets they have collected in a single database, (2) store more metadata about each data file, (3) develop queries that can find relationships among these disparate data types, and (4) plug any new functions developed around this database into existing analysis, visualization, and web tools, transparently to users. In this presentation, I will discuss the searchSCF package that is currently under development. This package includes a NoSQL database management system (MongoDB) and a set of Python tools that both ingests data into the database and supports user queries. I will also

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

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.).

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.

Past and present engagement in space activities in Central and Eastern Europe

NASA Astrophysics Data System (ADS)

Sagath, Daniel; Adriaensen, Maarten; Giannopapa, Christina

2018-07-01

Central and Eastern European (CEE) countries have been facing different cooperation models in the last fifty years regarding space policy and industrial activities. The period before the 1990s provided these countries with a strong heritage of expertise in space engagement which after the fall of the 'Eastern Block' offered the basis for cooperation with the other European countries and organisations. The way space policy in the CEE region was shaped during the early period and the way collaboration is conducted today have not been fully analysed. The objective of this paper is to provide a holistic analysis of the evolution of past and present developments of the CEE countries in space activities. The main focus of this paper is given to the Intercosmos period before the 1990s and following that, the integration process of these countries to the European Space Agency (ESA). Additionally, the CEE countries have been engaging in cooperation with other space agencies in Europe and outside. The countries also participate through the EU and its two flagship programmes Galileo and Copernicus amongst others. Furthermore, this paper provides an overview of the ESA accession process established in the early 2000s as ESA responded to the increasing interest of the CEE countries to engage in cooperation in the field of space. The comparison of both, historical and recent developments on CEE countries in space activities, indicates that CEE region has the basis for integrating in the European space sector. Participation in ESA and collaboration with other space faring nations is needed to ensure successful transformation of both their scientific and industrial basis as well as their governance, to the evolving space sector while utilizing the heritage obtained through the past engagements.

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…

History of Los Alamos Participation in Active Experiments in Space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pongratz, Morris B.

Beginning with the Teak nuclear test in 1958, Los Alamos has a long history of participation in active experiments in space. The last pertinent nuclear tests were the five explosions as part of the Dominic series in 1962. The Partial Test Ban Treaty signed in August 1963 prohibited all test detonations of nuclear weapons except for those conducted underground. Beginning with the “Apple” thermite barium release in June 1968 Los Alamos has participated in nearly 100 non-nuclear experiments in space, the last being the NASA-sponsored “AA-2” strontium and europium doped barium thermite releases in the Arecibo beam in July ofmore » 1992. The rationale for these experiments ranged from studying basic plasma processes such as gradientdriven structuring and velocity-space instabilities to illuminating the convection of plasmas in the ionosphere and polar cap to ionospheric depletion experiments to the B.E.A.R. 1-MeV neutral particle beam test in 1989. This report reviews the objectives, techniques and diagnostics of Los Alamos participation in active experiments in space.« less

Selected OAST/OSSA space experiment activities in support of Space Station Freedom

NASA Astrophysics Data System (ADS)

Delombard, Richard

The Space Experiments Division at NASA Lewis Research Center is developing technology and science space experiments for the Office of Aeronautics and Space Technology (OAST) and the Office of Space Sciences and Applications (OSSA). Selected precursor experiments and technology development activities supporting the Space Station Freedom (SSF) are presented. The Tank Pressure Control Experiment (TPCE) is an OAST-funded cryogenic fluid dynamics experiment, the objective of which is to determine the effectiveness of jet mixing as a means of equilibrating fluid temperatures and controlling tank pressures, thereby permitting the design of lighter cryogenic tanks. The information from experiments such as this will be utilized in the design and operation of on board cryogenic storage for programs such as SSF. The Thermal Energy Storage Flight Project (TES) is an OAST-funded thermal management experiment involving phase change materials for thermal energy storage. The objective of this project is to develop and fly in-space experiments to characterize void shape and location in phase change materials used in a thermal energy storage configuration representative of an advanced solar dynamic system design. The information from experiments such as this will be utilized in the design of future solar dynamic power systems. The Solar Array Module Plasma Interaction Experiment (SAMPIE) is an OAST-funded experiment to determine the environmental effects of the low earth orbit (LEO) space plasma environment on state-of-the-art solar cell modules biased to high potentials relative to the plasma. Future spacecraft designs and structures will push the operating limits of solar cell arrays and other high voltage systems. SAMPIE will provide key information necessary for optimum module design and construction. The Vibration Isolation Technology (VIT) Advanced Technology Development effort is funded by OSSA to provide technology necessary to maintain a stable microgravity environment for

Selected OAST/OSSA space experiment activities in support of Space Station Freedom

NASA Technical Reports Server (NTRS)

Delombard, Richard

1992-01-01

The Space Experiments Division at NASA Lewis Research Center is developing technology and science space experiments for the Office of Aeronautics and Space Technology (OAST) and the Office of Space Sciences and Applications (OSSA). Selected precursor experiments and technology development activities supporting the Space Station Freedom (SSF) are presented. The Tank Pressure Control Experiment (TPCE) is an OAST-funded cryogenic fluid dynamics experiment, the objective of which is to determine the effectiveness of jet mixing as a means of equilibrating fluid temperatures and controlling tank pressures, thereby permitting the design of lighter cryogenic tanks. The information from experiments such as this will be utilized in the design and operation of on board cryogenic storage for programs such as SSF. The Thermal Energy Storage Flight Project (TES) is an OAST-funded thermal management experiment involving phase change materials for thermal energy storage. The objective of this project is to develop and fly in-space experiments to characterize void shape and location in phase change materials used in a thermal energy storage configuration representative of an advanced solar dynamic system design. The information from experiments such as this will be utilized in the design of future solar dynamic power systems. The Solar Array Module Plasma Interaction Experiment (SAMPIE) is an OAST-funded experiment to determine the environmental effects of the low earth orbit (LEO) space plasma environment on state-of-the-art solar cell modules biased to high potentials relative to the plasma. Future spacecraft designs and structures will push the operating limits of solar cell arrays and other high voltage systems. SAMPIE will provide key information necessary for optimum module design and construction. The Vibration Isolation Technology (VIT) Advanced Technology Development effort is funded by OSSA to provide technology necessary to maintain a stable microgravity environment for

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.

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.

Morphing Compression Garments for Space Medicine and Extravehicular Activity Using Active Materials.

PubMed

Holschuh, Bradley T; Newman, Dava J

2016-02-01

Compression garments tend to be difficult to don/doff, due to their intentional function of squeezing the wearer. This is especially true for compression garments used for space medicine and for extravehicular activity (EVA). We present an innovative solution to this problem by integrating shape changing materials-NiTi shape memory alloy (SMA) coil actuators formed into modular, 3D-printed cartridges-into compression garments to produce garments capable of constricting on command. A parameterized, 2-spring analytic counterpressure model based on 12 garment and material inputs was developed to inform garment design. A methodology was developed for producing novel SMA cartridge systems to enable active compression garment construction. Five active compression sleeve prototypes were manufactured and tested: each sleeve was placed on a rigid cylindrical object and counterpressure was measured as a function of spatial location and time before, during, and after the application of a step voltage input. Controllable active counterpressures were measured up to 34.3 kPa, exceeding the requirement for EVA life support (29.6 kPa). Prototypes which incorporated fabrics with linear properties closely matched analytic model predictions (4.1%/-10.5% error in passive/active pressure predictions); prototypes using nonlinear fabrics did not match model predictions (errors >100%). Pressure non-uniformities were observed due to friction and the rigid SMA cartridge structure. To our knowledge this is the first demonstration of controllable compression technology incorporating active materials, a novel contribution to the field of compression garment design. This technology could lead to easy-to-don compression garments with widespread space and terrestrial applications.

Toroidal figures of equilibrium from a second-order accurate, accelerated SCF method with subgrid approach

NASA Astrophysics Data System (ADS)

Huré, J.-M.; Hersant, F.

2017-02-01

We compute the structure of a self-gravitating torus with polytropic equation of state (EOS) rotating in an imposed centrifugal potential. The Poisson solver is based on isotropic multigrid with optimal covering factor (fluid section-to-grid area ratio). We work at second order in the grid resolution for both finite difference and quadrature schemes. For soft EOS (I.e. polytropic index n ≥ 1), the underlying second order is naturally recovered for boundary values and any other integrated quantity sensitive to the mass density (mass, angular momentum, volume, virial parameter, etc.), I.e. errors vary with the number N of nodes per direction as ˜1/N2. This is, however, not observed for purely geometrical quantities (surface area, meridional section area, volume), unless a subgrid approach is considered (I.e. boundary detection). Equilibrium sequences are also much better described, especially close to critical rotation. Yet another technical effort is required for hard EOS (n < 1), due to infinite mass density gradients at the fluid surface. We fix the problem by using kernel splitting. Finally, we propose an accelerated version of the self-consistent field (SCF) algorithm based on a node-by-node pre-conditioning of the mass density at each step. The computing time is reduced by a factor of 2 typically, regardless of the polytropic index. There is a priori no obstacle to applying these results and techniques to ellipsoidal configurations and even to 3D configurations.

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.

[Analysis of possible causes activation a stomach and pancreas excretory and incretory function after completion of space flight on the international space station].

PubMed

Afonin, B V

2013-01-01

The research excretory and incretory of activity of a stomach and pancreas is carried out at astronauts in the early period after completion of space flights of various duration. It is shown, that the increase of the contents of gastric and pancreatic enzymes and hormones (insulin and C-peptide) in blood reflects increased excretory and incretory activity of organs of gastroduodenal area which arises in weightlessness. The complex of countermeasures, which prevent ingress of subjects, infected by Helicobacter pylori in space flight crew, excluded participation of this microorganism in the mechanism of increase of secretory activity of a stomach. The absence of interrelation between increase of secretory activity of gastroduodenal area organs and space flights' duration has allowed to exclude the hypokinetic mechanism which determined by duration of stay in weightlessness. It was shown that after the end of space flights the increase ofbasal excretory activity of organs of gastroduodenal area occurs simultaneously with increase of a fasting insulin secretion. The changes in gastroduodenal area organs revealed after space flights were are compared to similar changes received in ground-based experiments, simulating hemodynamic reorganization in venous system of abdominal cavity, arising in weightlessness. The conclusion is made, that the basic mechanism of changes of a functional condition of digestive system in space flights, is determined by reorganization venous hemodynamic in abdominal cavity organs reproduced in ground experiments. Increase insulin and C-peptide after space flights are considered as hormonal component of this hemodynamic mechanism.

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.

C-Kit Promotes Growth and Migration of Human Cardiac Progenitor Cells via the PI3K-AKT and MEK-ERK Pathways

PubMed Central

Al-Maqtari, Tareq; Cao, Pengxiao; Keith, Matthew C. L.; Wysoczynski, Marcin; Zhao, John; Moore IV, Joseph B.; Bolli, Roberto

2015-01-01

A recent phase I clinical trial (SCIPIO) has shown that autologous c-kit+ cardiac progenitor cells (CPCs) improve cardiac function and quality of life when transplanted into patients with ischemic heart disease. Although c-kit is widely used as a marker of resident CPCs, its role in the regulation of the cellular characteristics of CPCs remains unknown. We hypothesized that c-kit plays a role in the survival, growth, and migration of CPCs. To test this hypothesis, human CPCs were grown under stress conditions in the presence or absence of SCF, and the effects of SCF-mediated activation of c-kit on CPC survival/growth and migration were measured. SCF treatment led to a significant increase in cell survival and a reduction in cell death under serum depletion conditions. In addition, SCF significantly promoted CPC migration in vitro. Furthermore, the pro-survival and pro-migratory effects of SCF were augmented by c-kit overexpression and abrogated by c-kit inhibition with imatinib. Mechanistically, c-kit activation in CPCs led to activation of the PI3K and the MAPK pathways. With the use of specific inhibitors, we confirmed that the SCF/c-kit-dependent survival and chemotaxis of CPCs are dependent on both pathways. Taken together, our findings suggest that c-kit promotes the survival/growth and migration of human CPCs cultured ex vivo via the activation of PI3K and MAPK pathways. These results imply that the efficiency of CPC homing to the injury site as well as their survival after transplantation may be improved by modulating the activity of c-kit. PMID:26474484

Active x-ray optics for high resolution space telescopes

NASA Astrophysics Data System (ADS)

Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

2017-11-01

The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin

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.

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.

Rat Stem-Cell Factor Induces Splenocytes Capable Of Regenerating The Thymus

PubMed Central

Migita, Russell T.; Trebasky, Lisa D.; Housman, Jerry M.; Elliott, Gary S.; Hendren, R. Wayne; Deprince, Randolph B.; Greiner, Dale L.

1992-01-01

Cytokine regulation of prethymic T-lymphoid progenitor-cell proliferation and/or differentiation has not been well-defined, although much is known of cytokine regulation of hemopoietic stem- and progenitor-cell development. Here we use a recently identified hemopoietic growth factor, stem-cell factor (SCF) (a form of the c-kit ligand), and a transplant model of thymocyte regeneration to assess the effect of SCF on the in vivo generation of prethymic, thymocyte progenitor-cell activity. We show that recombinant rat SCF (rrSCF164 administered to weanling rats selectively induces an increase in thymocyte progenitor activity in the spleens of treated rats as compared to rats treated with vehicle, polyethylene glycol (PEG)-conjugated rat albumin, or recombinant human granulocyte colony-stimulating factor (rhG-CSF). These data demonstrate that administration of SCF in vivo affects extrathymic-origin thymocyte regenerating cells and may influence, directly or indirectly, early prethymic stages of T-cell lymphopoiesis in addition to its known effect on early stages of myelopoiesis and erythropoiesis. PMID:1285280

High-level expression of human stem cell factor fused with erythropoietin mimetic peptide in Escherichia coli.

PubMed

Su, Lin; Chen, Song-Sen; Yang, Ke-Gong; Liu, Chang-Zheng; Zhang, Yan-Li; Liang, Zhi-Quan

2006-06-01

Stem cell factor (SCF) and erythropoietin are essential for normal erythropoiesis and induce proliferation and differentiation synergistically for erythroid progenitor cells. Here, we report our work on construction of SCF/erythropoietin mimetic peptide (EMP) fusion protein gene, in which human SCF cDNA (1-165aa) and EMP sequence (20aa) were connected using a short (GGGGS) or long (GGGGSGGGGGS) linker sequence. The SCF/EMP gene was cloned into the pBV220 vector and expressed in the Escherichia coli DH5alpha strain. The expression level of the fusion protein was about 30% of total cell protein. The resulting inclusion bodies were solubilized with 8 M urea, followed by dilution refolding. The renatured protein was subsequently purified by Q-Sepharose FF column. The final product was >95% pure by SDS-PAGE and the yield of fusion protein was about 40 mg/L of culture. UT-7 cell proliferation and human cord blood cell colony-forming assays showed that the fusion proteins exhibited more potent activity than recombinant human SCF, suggesting a new strategy to enhance biological activities of growth factors.

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,…

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

... 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 International... Liability for Science or Space Exploration Activities Unrelated to the International Space Station (OCT 2012...

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

... 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 International... Liability for Science or Space Exploration Activities Unrelated to the International Space Station (OCT 2012...

Active Control of Flexible Space Structures Using the Nitinol Shape Memory Actuators

DTIC Science & Technology

1987-10-01

number) FIELD !GROUP SUBGROUP I Active Control, Nitinol Actuators, Space Structures 9. ABSTRACT (Continue on reverse if necessary and identify by block...number) Summarizes research progress in the feasibility demonstration of active vibration control using Nitinol shape memory actuators. Tests on...FLEXIBLE SPACE STRUCTURES USING NITINOL SHAPE MEMORY ACTUATORS FINAL REPORT FOR PHASE I SDIO CONTRACT #F49620-87-C-0035 0 BY DR. AMR M. BAZ KARIM R

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…

Compound Structure-Independent Activity Prediction in High-Dimensional Target Space.

PubMed

Balfer, Jenny; Hu, Ye; Bajorath, Jürgen

2014-08-01

Profiling of compound libraries against arrays of targets has become an important approach in pharmaceutical research. The prediction of multi-target compound activities also represents an attractive task for machine learning with potential for drug discovery applications. Herein, we have explored activity prediction in high-dimensional target space. Different types of models were derived to predict multi-target activities. The models included naïve Bayesian (NB) and support vector machine (SVM) classifiers based upon compound structure information and NB models derived on the basis of activity profiles, without considering compound structure. Because the latter approach can be applied to incomplete training data and principally depends on the feature independence assumption, SVM modeling was not applicable in this case. Furthermore, iterative hybrid NB models making use of both activity profiles and compound structure information were built. In high-dimensional target space, NB models utilizing activity profile data were found to yield more accurate activity predictions than structure-based NB and SVM models or hybrid models. An in-depth analysis of activity profile-based models revealed the presence of correlation effects across different targets and rationalized prediction accuracy. Taken together, the results indicate that activity profile information can be effectively used to predict the activity of test compounds against novel targets. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The relationship of physical activity and overweight to objectively measured green space accessibility and use

PubMed Central

2013-01-01

This study examines the association between objectively measured access to green space, frequency of green space use, physical activity, and the probability of being overweight or obese in the city of Bristol, England. Data from the Bristol Quality of Life in your Neighbourhood survey for 6,821 adults were combined with a comprehensive GIS database of neighbourhood and green space characteristics.. A range of green space accessibility measures were computed. Associations between accessibility and the odds of respondents achieving a recommended 30 minutes or more of moderate activity five times a week, or being overweight or obese, were examined using logistic regression. Results showed that the reported frequency of green space use declined with increasing distance. The study also found that respondents living closest to the type of green space classified as a Formal park were more likely to achieve the physical activity recommendation and less likely to be overweight or obese. The association with physical activity, but not with overweight or obesity, remained after adjustment for respondent characteristics, area deprivation, and a range of characteristics of the neighbourhood environment. The findings suggest that the provision of good access to green spaces in urban areas may help promote population physical activity. PMID:20060635

Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus).

PubMed

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.

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

NASA Stennis Space Center Test Technology Branch Activities

NASA Technical Reports Server (NTRS)

Solano, Wanda M.

2000-01-01

This paper provides a short history of NASA Stennis Space Center's Test Technology Laboratory and briefly describes the variety of engine test technology activities and developmental project initiatives. Theoretical rocket exhaust plume modeling, acoustic monitoring and analysis, hand held fire imaging, heat flux radiometry, thermal imaging and exhaust plume spectroscopy are all examples of current and past test activities that are briefly described. In addition, recent efforts and visions focused on accomodating second, third, and fourth generation flight vehicle engine test requirements are discussed.

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.

Data on quantification of signaling pathways activated by KIT and PDGFRA mutants.

PubMed

Bahlawane, Christelle; Schmitz, Martine; Letellier, Elisabeth; Arumugam, Karthik; Nicot, Nathalie; Nazarov, Petr V; Haan, Serge

2016-12-01

The present data are related to the article entitled "Insights into ligand stimulation effects on gastro-intestinal stromal tumors signaling" (C. Bahlawane, M. Schmitz, E. Letellier, K. Arumugam, N. Nicot, P.V. Nazarov, S. Haan, 2016) [1]. Constitutive and ligand-derived signaling pathways mediated by KIT and PDGFRA mutated proteins found in gastrointestinal stromal tumors (GIST) were compared. Expression of mutant proteins was induced by doxycycline in an isogenic background (Hek293 cells). Kit was identified by FACS at the cell surface and found to be quickly degraded or internalized upon SCF stimulation for both Kit Wild type and Kit mutant counterparts. Investigation of the main activated pathways in GIST unraveled a new feature specific for oncogenic KIT mutants, namely their ability to be further activated by Kit ligand, the stem cell factor (scf). We were also able to identify the MAPK pathway as the most prominent target for a common inhibition of PDGFRA and KIT oncogenic signaling. Western blotting and micro-array analysis were applied to analyze the capacities of the mutant to induce an effective STATs response. Among all Kit mutants, only Kit Ex11 deletion mutant was able to elicit an effective STATs response whereas all PDGFRA were able to do so.

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.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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;

Integrating high electrical conductivity and photocatalytic activity in cotton fabric by cationizing for enriched coating of negatively charged graphene oxide.

PubMed

Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Jeong, Sung Hoon

2015-10-05

Electroconductive textiles have attended tremendous focus recently and researchers are making efforts to increase conductivity of e-textiles, in order to increase the use of such flexible and low cost textile materials. In this study, surface conductivity and photo catalytic activity of standard cotton fabric (SCF) was enhanced by modifying its surface charge, from negative to positive, using Bovine Serum Albumin (BSA) as a cationic agent, to convert it into cationised cotton fabric (CCF). Then, both types of fabrics were dip coated with a simple dip and dry technique for the adsorption of negatively charged graphene oxide (GO) sheets onto its surface. This resulted in 67.74% higher loading amount of GO on the CCF making self-assembly. Finally, this coating was chemically converted by vapor reduction using hydrazine hydrate to reduced graphene oxide (rGO) for restoration of a high electrical conductivity at the fabric surface. Our results revealed that with such high loading of GO, the surface resistance of CCF was only 40Ω/sq as compared to 510Ω/sq of the SCF and a 66% higher photo catalytic activity was also achieved through cationization for improved GO coating. Graphene coated SCF and CCF were characterized using FE-SEM, FTIR, Raman, UV-vis, WAXD, EDX and XPS spectroscopy to ascertain successful reduction of GO to rGO. The effect of BSA treatment on adsorption of cotton fabric was studied using drop shape analyzer to measure contact angle and for thermal and mechanical resistance, the fabric was tested for TGA and tensile strength, respectively. rGO coated fabric also showed slightly improved thermal stability yet a minor loss of strength was observed. The high flexibility, photocatalytic activity and excellent conductivity of this fabric suggests that it can be used as an electrode material for various applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... Space Station” (the “Intergovernmental Agreement”) has entered into force, in accordance with Article 25... by Space Objects, which entered into force on September 1, 1972, where the person, entity, or... for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System...

Non-orthogonal internally contracted multi-configurational perturbation theory (NICPT): Dynamic electron correlation for large, compact active spaces

NASA Astrophysics Data System (ADS)

Kähler, Sven; Olsen, Jeppe

2017-11-01

A computational method is presented for systems that require high-level treatments of static and dynamic electron correlation but cannot be treated using conventional complete active space self-consistent field-based methods due to the required size of the active space. Our method introduces an efficient algorithm for perturbative dynamic correlation corrections for compact non-orthogonal MCSCF calculations. In the algorithm, biorthonormal expansions of orbitals and CI-wave functions are used to reduce the scaling of the performance determining step from quadratic to linear in the number of configurations. We describe a hierarchy of configuration spaces that can be chosen for the active space. Potential curves for the nitrogen molecule and the chromium dimer are compared for different configuration spaces. Already the most compact spaces yield qualitatively correct potentials that with increasing size of configuration spaces systematically approach complete active space results.

ACOSS-16 (Active Control of Space Structures)

DTIC Science & Technology

1982-10-01

RADC-TR-82-225 Final Technical Report October 1982 SACOSS- 16 (ACTIVE CONTROL OF SPACE ~ STRUCTURES) Honeywell Sponsored by Defense Advanced Research ...Defense Ad. vanced Research Projects Agency or the U.S. Government. ROME AIR DEVELOPMENT CENTER Air Force Systems Command Griffiss Air Force Base, NY 13441...ELEMENT. PROJECT, TASK lo, .’ H _onevwell Systems & Research Center AREA & WORK UNIT NUMBERS 2600 Ridgway Parkway, P0 Box 312 62301E Minneapolis MN

Effects of repeated simulated removal activities on feral swine movements and space use

USGS Publications Warehouse

Fischer, Justin W.; McMurtry , Dan; Blass, Chad R.; Walter, W. David; Beringer, Jeff; VerCauterren, Kurt C.

2016-01-01

Abundance and distribution of feral swine (Sus scrofa) in the USA have increased dramatically during the last 30 years. Effective measures are needed to control and eradicate feral swine populations without displacing animals over wider areas. Our objective was to investigate effects of repeated simulated removal activities on feral swine movements and space use. We analyzed location data from 21 feral swine that we fitted with Global Positioning System harnesses in southern MO, USA. Various removal activities were applied over time to eight feral swine before lethal removal, including trapped-and-released, chased with dogs, chased with hunter, and chased with helicopter. We found that core space-use areas were reduced following the first removal activity, whereas overall space-use areas and diurnal movement distances increased following the second removal activity. Mean geographic centroid shifts did not differ between pre- and post-periods for either the first or second removal activities. Our information on feral swine movements and space use precipitated by human removal activities, such as hunting, trapping, and chasing with dogs, helps fill a knowledge void and will aid wildlife managers. Strategies to optimize management are needed to reduce feral swine populations while preventing enlarged home ranges and displacing individuals, which could lead to increased disease transmission risk and human-feral swine conflict in adjacent areas.

Skin blood flow with elastic compressive extravehicular activity space suit.

PubMed

Tanaka, Kunihiko; Gotoh, Taro M; Morita, Hironobu; Hargens, Alan R

2003-10-01

During extravehicular activity (EVA), current space suits are pressurized with 100% oxygen at approximately 222 mmHg. A tight elastic garment, or mechanical counter pressure (MCP) suit that generates pressure by compression, may have several advantages over current space suit technology. In this study, we investigated local microcirculatory effects produced with negative ambient pressure with an MCP sleeve. The MCP glove and sleeve generated pressures similar to the current space suit. MCP remained constant during negative pressure due to unchanged elasticity of the material. Decreased skin capillary blood flow and temperature during MCP compression was counteracted by greater negative pressure or a smaller pressure differential.

75 FR 18846 - Agency Recordkeeping/Reporting Requirements Under Emergency Review by the Office of Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

...: Strengthening Communities Fund Program Evaluation. OMB No.: New Collection. Description: This proposed information collection activity is to obtain evaluation information from Strengthening Communities Fund (SCF... authorized in the American Recovery and Reinvestment Act of 2009 (ARRA). The SCF evaluation is an important...

75 FR 16138 - Agency Recordkeeping/Reporting Requirements Under Emergency Review by the Office of Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-31

...: Strengthening Communities Fund Program Evaluation. OMB No.: New collection. Description: This proposed information collection activity is to obtain evaluation information from Strengthening Communities Fund (SCF... authorized in the American Recovery and Reinvestment Act of 2009 (ARPA). The SCF evaluation is an important...

Space, body, time and relationship experiences of recess physical activity: a qualitative case study among the least physical active schoolchildren.

PubMed

Pawlowski, Charlotte Skau; Andersen, Henriette Bondo; Tjørnhøj-Thomsen, Tine; Troelsen, Jens; Schipperijn, Jasper

2016-01-06

Increasing recess physical activity has been the aim of several interventions, as this setting can provide numerous physical activity opportunities. However, it is unclear if these interventions are equally effective for all children, or if they only appeal to children who are already physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. The study builds on ethnographic fieldwork in a public school in Denmark using a combination of participatory photo interviews and participant observation. Thirty-seven grade five children (11-12 years old) were grouped in quartiles based on their objectively measured daily physical activity levels. Eight children in the lowest activity quartile (six girls) were selected to participate in the study. To avoid stigmatising and to make generalisations more reliable we further recruited eight children from the two highest activity quartiles (four girls) to participate. An analysis of the least physically active children's "lived experiences" of space, body, time and relations revealed several key factors influencing their recess physical activity: perceived classroom safety, indoor cosiness, lack of attractive outdoor facilities, bodily dissatisfaction, bodily complaints, tiredness, feeling bored, and peer influence. We found that the four existential lifeworlds provided an in-depth understanding of the least physically active children's "lived experiences" of recess physical activity. Our findings imply that specific intervention strategies might be needed to increase the least physically active children's physical activity level. For example, rethinking the classroom as a space for physical activity, designing schoolyards with smaller secluded spaces and varied facilities, improving children's self-esteem and body image, e.g., during physical education, and

Understanding human activity patterns based on space-time-semantics

NASA Astrophysics Data System (ADS)

Huang, Wei; Li, Songnian

2016-11-01

Understanding human activity patterns plays a key role in various applications in an urban environment, such as transportation planning and traffic forecasting, urban planning, public health and safety, and emergency response. Most existing studies in modeling human activity patterns mainly focus on spatiotemporal dimensions, which lacks consideration of underlying semantic context. In fact, what people do and discuss at some places, inferring what is happening at the places, cannot be simple neglected because it is the root of human mobility patterns. We believe that the geo-tagged semantic context, representing what individuals do and discuss at a place and a specific time, drives a formation of specific human activity pattern. In this paper, we aim to model human activity patterns not only based on space and time but also with consideration of associated semantics, and attempt to prove a hypothesis that similar mobility patterns may have different motivations. We develop a spatiotemporal-semantic model to quantitatively express human activity patterns based on topic models, leading to an analysis of space, time and semantics. A case study is conducted using Twitter data in Toronto based on our model. Through computing the similarities between users in terms of spatiotemporal pattern, semantic pattern and spatiotemporal-semantic pattern, we find that only a small number of users (2.72%) have very similar activity patterns, while the majority (87.14%) show different activity patterns (i.e., similar spatiotemporal patterns and different semantic patterns, similar semantic patterns and different spatiotemporal patterns, or different in both). The population of users that has very similar activity patterns is decreased by 56.41% after incorporating semantic information in the corresponding spatiotemporal patterns, which can quantitatively prove the hypothesis.

Earth-Space Science Activity Syllabus for Elementary and Junior High School Teachers of Science.

ERIC Educational Resources Information Center

Maier, Jack; And Others

This syllabus is a collection of earth-space science laboratory activities and demonstrations intended for use at the elementary and junior high school levels. The activities are grouped into eight subject sections: Astronomy, Light, Magnetism, Electricity, Geology, Weather, Sound, and Space. Each section begins with brief background information,…

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

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.

The regulatory effect of SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-l] benzenesulfonamide) on stem cell factor induced migration of mast cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Su-Jin; College of Oriental Medicine, Kyung Hee University, 1 Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701; Jeong, Hyun-Ja

SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-]benzenesulfonamide; C{sub 16}H{sub 11}ClF{sub 3}N{sub 3}O{sub 2}S), is a highly selective cyclooxygenase (COX)-2 inhibitor. Recently, there have been reports that SC-236 protects against cartilage damage in addition to reducing inflammation and pain in osteoarthritis. However, the mechanism involved in the inflammatory allergic reaction has not been examined. Mast cells accumulation can be related to inflammatory conditions, including allergic rhinitis, asthma, and rheumatoid arthritis. The aim of the present study is to investigate the effects of SC-236 on stem cell factor (SCF)-induced migration, morphological alteration, and cytokine production of rat peritoneal mast cells (RPMCs). We observed that SCF significantly inducedmore » the migration and morphological alteration. The ability of SCF to enhance migration and morphological alteration was abolished by treatment with SC-236. In addition, production of tumor necrosis factor (TNF)-{alpha}, interleukin (IL)-1{beta}, and vascular endothelial growth factor (VEGF) production induced by SCF was significantly inhibited by treatment with SC-236. Previous work has demonstrated that SCF-induced migration and cytokine production of mast cells require p38 MAPK activation. We also showed that SC-236 suppresses the SCF-induced p38 MAPK activation in RPMCs. These data suggest that SC-236 inhibits migration and cytokine production through suppression of p38 MAPK activation. These results provided new insight into the pharmacological actions of SC-236 and its potential therapeutic role in the treatment of inflammatory allergic diseases.« less

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.

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.

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

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.

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.

Novel strategy to implement active-space coupled-cluster methods

NASA Astrophysics Data System (ADS)

Rolik, Zoltán; Kállay, Mihály

2018-03-01

A new approach is presented for the efficient implementation of coupled-cluster (CC) methods including higher excitations based on a molecular orbital space partitioned into active and inactive orbitals. In the new framework, the string representation of amplitudes and intermediates is used as long as it is beneficial, but the contractions are evaluated as matrix products. Using a new diagrammatic technique, the CC equations are represented in a compact form due to the string notations we introduced. As an application of these ideas, a new automated implementation of the single-reference-based multi-reference CC equations is presented for arbitrary excitation levels. The new program can be considered as an improvement over the previous implementations in many respects; e.g., diagram contributions are evaluated by efficient vectorized subroutines. Timings for test calculations for various complete active-space problems are presented. As an application of the new code, the weak interactions in the Be dimer were studied.

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

Astronaut activity in weightlessness and unsupported space

NASA Technical Reports Server (NTRS)

Ivanov, Y. A.; Popov, V. A.; Kachaturyants, L. S.

1975-01-01

For the purpose of study of the performance ability of a human operator in prolonged weightless conditions was studied by the following methods: (1) psychophysiological analysis of certain operations; (2) the dynamic characteristics of a man, included in a model control system, with direct and delayed feedback; (3) evaluation of the singularities of analysis and quality of the working memory, in working with outlines of patterned and random lines; and (4) biomechanical analysis of spatial orientation and motor activity in unsupported space.

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.

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... by Space Objects, which entered into force on September 1, 1972, where the person, entity, 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 AND...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... by Space Objects, which entered into force on September 1, 1972, where the person, entity, 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 AND...

Stem cell factor and interleukin-2/15 combine to enhance MAPK-mediated proliferation of human natural killer cells

PubMed Central

Benson, Don M.; Yu, Jianhua; Becknell, Brian; Wei, Min; Freud, Aharon G.; Ferketich, Amy K.; Trotta, Rossana; Perrotti, Danilo; Briesewitz, Roger

2009-01-01

Stem cell factor (SCF) promotes synergistic cellular proliferation in combination with several growth factors, and appears important for normal natural killer (NK)–cell development. CD34+ hematopoietic precursor cells (HPCs) require interleukin-15 (IL-15) for differentiation into human NK cells, and this effect can be mimicked by IL-2. Culture of CD34+ HPCs or some primary human NK cells in IL-2/15 and SCF results in enhanced growth compared with either cytokine alone. The molecular mechanisms responsible for this are unknown and were investigated in the present work. Activation of NK cells by IL-2/15 increases expression of c-kit whose kinase activity is required for synergy with IL-2/15 signaling. Mitogen-activated protein kinase (MAPK) signaling intermediaries that are activated both by SCF and IL-2/15 are enhanced in combination to facilitate earlier cell-cycle entry. The effect results at least in part via enhanced MAPK-mediated modulation of p27 and CDK4. Collectively the data reveal a novel mechanism by which SCF enhances cellular proliferation in combination with IL-2/15 in primary human NK cells. PMID:19060242

Potential energy surfaces of the ground and low-lying states of HCCS and NCS: CASSCF, MRCI and CCSD(T) studies

NASA Astrophysics Data System (ADS)

Li, Yumin; Iwata, Suehiro

1997-07-01

For astronomically interesting molecules, HCCS and NCS, the equilibrium geometries and potential energy curves of three states (X 2Π, A 2Π and B 2Σ+) as well as vertical excitation energies are studied using complete active space SCF (CASSCF), multi-reference configuration interaction (MRCI) and coupled cluster (CCSD(T)) methods with cc-pVTZ basis sets. The difference and similarity in the three states of HCCS and NCS are illustrated. The results obtained are in good agreement with available experimental data.

Comparing Paper and Tablet Modes of Retrospective Activity Space Data Collection.

PubMed

Yabiku, Scott T; Glick, Jennifer E; Wentz, Elizabeth A; Ghimire, Dirgha; Zhao, Qunshan

2017-01-01

Individual actions are both constrained and facilitated by the social context in which individuals are embedded. But research to test specific hypotheses about the role of space on human behaviors and well-being is limited by the difficulty of collecting accurate and personally relevant social context data. We report on a project in Chitwan, Nepal, that directly addresses challenges to collect accurate activity space data. We test if a computer assisted interviewing (CAI) tablet-based approach to collecting activity space data was more accurate than a paper map-based approach; we also examine which subgroups of respondents provided more accurate data with the tablet mode compared to paper. Results show that the tablet approach yielded more accurate data when comparing respondent-indicated locations to the known locations as verified by on-the-ground staff. In addition, the accuracy of the data provided by older and less healthy respondents benefited more from the tablet mode.

Comparing Paper and Tablet Modes of Retrospective Activity Space Data Collection*

PubMed Central

Yabiku, Scott T.; Glick, Jennifer E.; Wentz, Elizabeth A.; Ghimire, Dirgha; Zhao, Qunshan

2018-01-01

Individual actions are both constrained and facilitated by the social context in which individuals are embedded. But research to test specific hypotheses about the role of space on human behaviors and well-being is limited by the difficulty of collecting accurate and personally relevant social context data. We report on a project in Chitwan, Nepal, that directly addresses challenges to collect accurate activity space data. We test if a computer assisted interviewing (CAI) tablet-based approach to collecting activity space data was more accurate than a paper map-based approach; we also examine which subgroups of respondents provided more accurate data with the tablet mode compared to paper. Results show that the tablet approach yielded more accurate data when comparing respondent-indicated locations to the known locations as verified by on-the-ground staff. In addition, the accuracy of the data provided by older and less healthy respondents benefited more from the tablet mode. PMID:29623133

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.

[A dynamic model of the extravehicular (correction of extravehicuar) activity space suit].

PubMed

Yang, Feng; Yuan, Xiu-gan

2002-12-01

Objective. To establish a dynamic model of the space suit base on the particular configuration of the space suit. Method. The mass of the space suit components, moment of inertia, mobility of the joints of space suit, as well as the suit-generated torques, were considered in this model. The expressions to calculate the moment of inertia were developed by simplifying the geometry of the space suit. A modified Preisach model was used to mathematically describe the hysteretic torque characteristics of joints in a pressurized space suit, and it was implemented numerically basing on the observed suit parameters. Result. A dynamic model considering mass, moment of inertia and suit-generated torques was established. Conclusion. This dynamic model provides some elements for the dynamic simulation of the astronaut extravehicular activity.

Nociceptive tuning by stem cell factor/c-Kit signaling.

PubMed

Milenkovic, Nevena; Frahm, Christina; Gassmann, Max; Griffel, Carola; Erdmann, Bettina; Birchmeier, Carmen; Lewin, Gary R; Garratt, Alistair N

2007-12-06

The molecular mechanisms regulating the sensitivity of sensory circuits to environmental stimuli are poorly understood. We demonstrate here a central role for stem cell factor (SCF) and its receptor, c-Kit, in tuning the responsiveness of sensory neurons to natural stimuli. Mice lacking SCF/c-Kit signaling displayed profound thermal hypoalgesia, attributable to a marked elevation in the thermal threshold and reduction in spiking rate of heat-sensitive nociceptors. Acute activation of c-Kit by its ligand, SCF, resulted in a reduced thermal threshold and potentiation of heat-activated currents in isolated small-diameter neurons and thermal hyperalgesia in mice. SCF-induced thermal hyperalgesia required the TRP family cation channel TRPV1. Lack of c-Kit signaling during development resulted in hypersensitivity of discrete mechanoreceptive neuronal subtypes. Thus, c-Kit can now be grouped with a small family of receptor tyrosine kinases, including c-Ret and TrkA, that control the transduction properties of sensory neurons.

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

Space Commercialization and the Development of Space Law

NASA Astrophysics Data System (ADS)

Yun, Zhao

2017-05-01

Shortly after the launch of the first manmade satellite in 1957, the United Nations (UN) took the lead in formulating international rules governing space activities. The five international conventions (i.e., the 1967 Outer Space Treaty, the 1968 Rescue Agreement, the 1972 Liability Convention, the 1975 Registration Convention, and the 1979 Moon Agreement) within the UN framework constitute the nucleus of space law; laying a solid legal foundation for securing the smooth development of space activities over the next few decades. Outer space was soon found to be a place with abundant opportunities for commercialization: with telecommunications services the first and most successful commercial application followed by remote sensing and global navigation services. In the last decade, the rapid development of space technologies brought space tourism and space mining to the forefront as well. With more and more commercial activities taking place on a daily basis from the 1980s on, existing space law faces severe challenges. The five conventions, which were enacted at a time when space was monopolized by two superpowers—the United States and the former Soviet Union—also failed to take into account the commercial aspect of space activities. Although there are urgent needs for new rules to deal with the ongoing trend of space commercialization, the international society faces difficulties in adopting new rules due to diversified national interests. As a result, it adjusts legislative strategies by enacting soft laws. In view of the difficulty in adopting binding rules at the international level, states are encouraged to enact their own national space legislation providing sufficient guidance for their domestic space commercial activities. It is expected that the development of soft laws and national space legislation will be the mainstream regulatory activities in the space field for the foreseeable future.

Minimizing Actuator-Induced Residual Error in Active Space Telescope Primary Mirrors

DTIC Science & Technology

2010-09-01

actuator geometry, and rib-to-facesheet intersection geometry are exploited to achieve improved performance in silicon carbide ( SiC ) mirrors . A...are exploited to achieve improved performance in silicon carbide ( SiC ) mirrors . A parametric finite element model is used to explore the trade space...MOST) finite element model. The move to lightweight actively-controlled silicon carbide ( SiC ) mirrors is traced back to previous generations of space

Skylab, Space Shuttle, Space Benefits Today and Tomorrow.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

The pamphlet "Skylab" describes very generally the kinds of activities to be conducted with the Skylab, America's first manned space station. "Space Shuttle" is a pamphlet which briefly states the benefits of the Space Shuttle, and a concise review of present and future benefits of space activities is presented in the pamphlet "Space Benefits…

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.

Space Station Freedom extravehicular activity systems evolution study

NASA Technical Reports Server (NTRS)

Rouen, Michael

1990-01-01

Evaluation of Space Station Freedom (SSF) support of manned exploration is in progress to identify SSF extravehicular activity (EVA) system evolution requirements and capabilities. The output from these studies will provide data to support the preliminary design process to ensure that Space Station EVA system requirements for future missions (including the transportation node) are adequately considered and reflected in the baseline design. The study considers SSF support of future missions and the EVA system baseline to determine adequacy of EVA requirements and capabilities and to identify additional requirements, capabilities, and necessary technology upgrades. The EVA demands levied by formal requirements and indicated by evolutionary mission scenarios are high for the out-years of Space Station Freedom. An EVA system designed to meet the baseline requirements can easily evolve to meet evolution demands with few exceptions. Results to date indicate that upgrades or modifications to the EVA system may be necessary to meet the full range of EVA thermal environments associated with the transportation node. Work continues to quantify the EVA capability in this regard. Evolution mission scenarios with EVA and ground unshielded nuclear propulsion engines are inconsistent with anthropomorphic EVA capabilities.

Creating Inclusive Physical Activity Spaces: The Case of Body-Positive Yoga

ERIC Educational Resources Information Center

Pickett, Andrew C.; Cunningham, George B.

2017-01-01

Purpose: Within the modern cultural climate, those in larger bodies face high levels of weight stigma, particularly in sport and physical activity spaces, which serves as a strong barrier to their participation. However, given the strong link between physical activity and general health and well-being for participants, it is important to explore…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pedersen, Malin; Loefstedt, Tobias; Sun Jianmin

Signaling by the receptor for stem cell factor (SCF), c-Kit, is of major importance for hematopoiesis, melanogenesis and reproduction, and the biological responses are commonly proliferation and cell survival. Thus, constitutive activation due to c-Kit mutations is involved in the pathogenesis of several forms of cancer, e.g. leukemias, gastrointestinal stromal tumors and testicular tumors. Tumor survival requires oxygen supply through induced neovascularization, a process largely mediated by the vascular endothelial growth factor (VEGF), a prominent target of the transcription factors hypoxia-inducible factor-1 (HIF-1) and HIF-2. Using Affymetrix microarrays we have identified genes that are upregulated following SCF stimulation. Interestingly, manymore » of the genes induced were found to be related to a hypoxic response. These findings were corroborated by our observation that SCF stimulation of the hematopoietic cell lines M-07e induces HIF-1{alpha} and HIF-2{alpha} protein accumulation at normoxia. In addition, SCF-induced HIF-1{alpha} was transcriptionally active, and transcribed HIF-1 target genes such as VEGF, BNIP3, GLUT1 and DEC1, an effect that could be reversed by siRNA against HIF-1{alpha}. We also show that SCF-induced accumulation of HIF-1{alpha} is dependent on both the PI-3-kinase and Ras/MEK/Erk pathways. Our data suggest a novel mechanism of SCF/c-Kit signaling in angiogenesis and tumor progression.« less

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)

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.

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... product or process except when such development is for Space Station-related activities in implementation...) All activities related to ground support, test, training, simulation, or guidance and control...

Kids in space: Measuring children's residential neighborhoods and other destinations using activity space GPS and wearable camera data.

PubMed

Chambers, T; Pearson, A L; Kawachi, I; Rzotkiewicz, Z; Stanley, J; Smith, M; Barr, M; Ni Mhurchu, C; Signal, L

2017-11-01

Defining the boundary of children's 'neighborhoods' has important implications for understanding the contextual influences on child health. Additionally, insight into activities that occur outside people's neighborhoods may indicate exposures that place-based studies cannot detect. This study aimed to 1) extend current neighborhood research, using data from wearable cameras and GPS devices that were worn over several days in an urban setting; 2) define the boundary of children's neighborhoods by using leisure time activity space data; and 3) determine the destinations visited by children in their leisure time, outside their neighborhoods. One hundred and fourteen children (mean age 12y) from Wellington, New Zealand wore wearable cameras and GPS recorders. Residential Euclidean buffers at incremental distances were paired with GPS data (thereby identifying time spent in different places) to explore alternative definitions of neighborhood boundaries. Children's neighborhood boundary was at 500 m. A newly developed software application was used to identify 'destinations' visited outside the neighborhood by specifying space-time parameters. Image data from wearable cameras were used to determine the type of destination. Children spent over half of their leisure time within 500 m of their homes. Children left their neighborhood predominantly to visit school (for leisure purposes), other residential locations (e.g. to visit friends) and food retail outlets (e.g. convenience stores, fast food outlets). Children spent more time at food retail outlets than at structured sport and in outdoor recreation locations combined. Person-centered neighborhood definitions may serve to better represent children's everyday experiences and neighborhood exposures than previous methods based on place-based measures. As schools and other residential locations (friends and family) are important destinations outside the neighborhood, such destinations should be taken into account. The

Supercritical fluid particle design for poorly water-soluble drugs (review).

PubMed

Sun, Yongda

2014-01-01

Supercritical fluid particle design (SCF PD) offers a number of routes to improve solubility and dissolution rate for enhancing the bioavailability of poorly water-soluble drugs, which can be adopted through an in-depth knowledge of SCF PD processes and the molecular properties of active pharmaceutical ingredients (API) and drug delivery system (DDS). Combining with research experiences in our laboratory, this review focuses on the most recent development of different routes (nano-micron particles, polymorphic particles, composite particles and bio-drug particles) to improve solubility and dissolution rate of poorly water-soluble drugs, covering the fundamental concept of SCF and the principle of SCF PD processes which are typically used to control particle size, shape, morphology and particle form and hence enable notable improvement in the dissolution rate of the poorly water-soluble drugs. The progress of the industrialization of SCF PD processes in pharmaceutical manufacturing environment with scaled-up plant under current good manufacturing process (GMP) specification is also considered in this review.

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.

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.

Space active optics: in flight aberrations correction for the next generation of large space telescopes

NASA Astrophysics Data System (ADS)

Laslandes, M.; Ferrari, M.; Hugot, E.; Lemaitre, G.

2017-11-01

The need for both high quality images and light structures is a constant concern in the conception of space telescopes. In this paper, we present an active optics system as a way to fulfill those two objectives. Indeed, active optics consists in controlling mirrors' deformations in order to improve the images quality [1]. The two main applications of active optics techniques are the in-situ compensation of phase errors in a wave front by using a corrector deformable mirror [2] and the manufacturing of aspherical mirrors by stress polishing or by in-situ stressing [3]. We will focus here on the wave-front correction. Indeed, the next generation of space telescopes will have lightweight primary mirrors; in consequence, they will be sensitive to the environment variations, inducing optical aberrations in the instrument. An active optics system is principally composed of a deformable mirror, a wave front sensor, a set of actuators deforming the mirror and control/command electronics. It is used to correct the wave-front errors due to the optical design, the manufacturing imperfections, the large lightweight primary mirrors' deflection in field gravity, the fixation devices, and the mirrors and structures' thermal distortions due to the local turbulence [4]. Active optics is based on the elasticity theory [5]; forces and/or load are used to deform a mirror. Like in adaptive optics, actuators can simply be placed under the optical surface [1,2], but other configurations have also been studied: a system's simplification, inducing a minimization of the number of actuators can be achieved by working on the mirror design [5]. For instance, in the so called Vase form Multimode Deformable Mirror [6], forces are applied on an external ring clamped on the pupil. With this method, there is no local effect due to the application of forces on the mirror's back face. Furthermore, the number of actuators needed to warp the mirror does not depend on the pupil size; it is a fully

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.

Beyond Physical Activity: The Importance of Play and Nature-Based Play Spaces for Children's Health and Development.

PubMed

Herrington, Susan; Brussoni, Mariana

2015-12-01

The reduction of child obesity continues to be a challenge worldwide. Research indicates that playing outdoors, particularly in natural play spaces, boosts children's physical activity, potentially decreasing childhood obesity. We present evidence that natural play spaces also provide for more diverse forms of play for children of varying ages and competencies. This is crucial because play spaces designed expressly for physical activity may not increase physical activity among less active children. Moreover, when researchers only examine physical activity in play, they overlook the valuable contributions that play makes to other aspects of children's health and development. To enhance research on children and their play environments, we introduce the theory of play affordances. To assist in the creation of more natural play spaces, we describe the Seven Cs, an evidence-based approach for designing children's play spaces that promotes diverse play. We end with some preliminary insights from our current research using the Seven Cs to illustrate the connections between play, nature, and children's healthy development.

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.

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.

In vitro long-term culture of human primitive hematopoietic cells supported by murine stromal cell line MS-5.

PubMed

Nishi, N; Ishikawa, R; Inoue, H; Nishikawa, M; Yoneya, T; Kakeda, M; Tsumura, H; Ohashi, H; Mori, K J

1997-04-01

When Lin-CD34+CD38- cells from normal human cord blood were cocultured with MS-5, colony forming cells were maintained for over 8 weeks. Prevention of contact between MS-5 and Lin-CD34+CD38- cells by using a membrane filter was negligible for this activity, indicating that the activity of MS-5 on human primitive hematopoietic cells may be due to soluble factor(s) secreted from MS-5. We tried to purify this activity by a [3H]TdR incorporation assay. The activity was found in 150 kD fraction and was neutralized with anti-mSCF (stem cell factor) antibody. Another 20-30 kD fraction synergized with mSCF to stimulate the growth of Lin-CD34+CD38- cells but failed alone. This fraction supported the growth of the G-CSF (granulocyte-colony stimulating factor)-dependent cell line FD/GR3, FDC-P2 transfected with mG-CSF receptor cDNA. This synergy was canceled in the presence of soluble mG-CSF receptor. Addition of anti-mSCF antibody and soluble mG-CSF receptor to the culture completely abrogated the activity of MS-5-culture supernatant. These results indicate the activity of MS-5 on Lin-CD34+CD38- cells is due to synergistic effect of mSCF and mG-CSF.

Hurley in the FWD FD during docking activities of Space Shuttle Endeavour

NASA Image and Video Library

2009-07-17

S127-E-006573 (17 July 2009) --- Astronaut Doug Hurley is at the pilot station on Endeavour's flight deck during rendezvous and docking activities between space shuttle and the the International Space Station. Later the STS-127 crew docked the shuttle with the orbital outpost and ingressed it, bringing the population of the ISS to a record 13 people for the time being.

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.

In vitro hydrolytic digestion, glycemic response in dogs, and true metabolizable energy content of soluble corn fibers.

PubMed

de Godoy, M R C; Knapp, B K; Parsons, C M; Swanson, K S; Fahey, George C

2014-06-01

The objective of this research was to measure in vitro hydrolytic digestion, glycemic and insulinemic responses in dogs, and true ME (TMEn) content of select soluble corn fibers (SCF) in roosters. The first generation (G1) SCF included hydrochloric acid-treated corn syrup (G1-CS-HCl), an SCF with an increased total dietary fiber (TDF) content (G1-SCF-HCl), an SCF that was spray-dried (G1-SCF-SD), and a hydrogenated SCF (G1-SCF-hydrog). The second generation (G2) SCF included those prepared using phosphoric acid catalyzation in both a liquid [G2-SCF-phos (Lq)] and powder [G2-SCF-phos (Pw)] form, and SCF that were prepared using hydrochloric acid catalyzation in both a liquid [G2-SCF-HCl (Lq)] and powder [G2-SCF-HCl (Pw)] form. Also, in the G2 set of samples were SCF prepared using the same method, but in 3 separate batches, all of which contained 70% TDF and 15% sugars. Two were in liquid form [G2-SCF-phos+HCl (Lq1)] and [G2-SCF-phos+HCl (Lq2)], and one in powder form ([G2-SCF-phos+HCl (Pw)]. A lower sugar form (80% TDF and 5% sugar) of SCF was also evaluated (G2-SCF-low sugar). Glucose was the major free sugar and bound monosaccharide in all SCF except for G1-SCF-hydrog that had greater concentrations of sorbitol. All SCF had intermediate to low amounts of monosaccharides released as a result of in vitro hydrolytic digestion, with glucose being the primary sugar component released. The G1-SCF were more digestible in vitro (approximately 50%) compared to G2-SCF (approximately 32%). All SCF had attenuated glycemic responses in adult dogs compared to a maltodextrin control (P < 0.05). The G2-SCF, on average, had lower glycemic responses and TMEn values in roosters than G1-SCF. All SCF had low free sugar concentrations with varying degrees of resistance to digestion, reduced caloric content, and attenuated glycemic and insulinemic responses in adult dogs. These ingredients are potential candidates for inclusion in reduced calorie and low glycemic canine diets.

Undeveloped green space and free-time physical activity in 11 to 13-year-old children.

PubMed

Janssen, Ian; Rosu, Andrei

2015-02-21

Research on the association between the physical environment and physical activity in children has focused on built and developed features or total green space. The impact of natural, undeveloped green spaces is unknown. The objective of this study was to determine whether the presence of undeveloped green spaces in the home neighborhood are associated with physical activity in 11 to 13-year-olds. This was a cross-sectional study of grade 6 to 8 urban residing Canadian students who participated in the 2009/10 Health Behaviour in School-Aged Children survey. Children self-reported the frequency they participated in physical activity in their free-time outside of school hours. Geographic Information Systems (GIS) were used to assess the proportion of land area within 1 km of participants' homes that was devoted to publicly accessible meadows (i.e., field vegetated primarily by grass and other non-woody plants) and treed areas (i.e., field vegetated primarily by trees and shrubs). Ordinal logistic regression models were used to examine the relationships between the undeveloped green space areas and free-time physical activity. Several intrapersonal, family, and neighborhood environment factors were controlled for in these regression models. The proportion of neighborhood land covered by meadows was not associated with the physical activity outcome (p > 0.6). However, the proportion of neighborhood land covered by treed areas was independently associated with the physical activity outcome (p = 0.02). For each additional 5% increase in the proportion of neighborhood land covered by treed areas there was a corresponding 5% increase (95% confidence interval: 1-10% increase) in the relative odds of increasing free-time physical activity outside of school hours. The physical activity levels of 11 to 13-year-old children was associated with the amount of space in their home neighborhood devoted to treed areas.

Frontoparietal Activation Distinguishes Face and Space from Artifact Concepts

PubMed Central

Chen, Chi-Hua; Zeki, Semir

2012-01-01

Empirical and theoretical studies suggest that human knowledge is partly based on innate concepts that are experience-independent. We can, therefore, consider concepts underlying our knowledge as being broadly divided into inherited and acquired ones. Using fMRI, we studied the brain reaction in 20 subjects to violation of face, space (inherited), and artifact (acquired) concepts by presenting them with deformed faces, impossible figures (i.e., impossible chairs), and deformed planes, respectively, as well as their normal counterparts. Violation of the inherited concepts of face and space led to significant activation in frontoparietal cortex, whereas artifacts did not, thus distinguishing neurologically between the two categories. Participants were further exposed to these deformities daily for 1 month to test the supposition that inherited concepts are not modifiable, hence that prolonged exposure would not change the brain circuits that are engaged when viewing them. Consistent with this supposition, our results showed no significant change in activation for both categories, suggesting that such concepts are stable at the neural level at least within a time frame of 1 month. Finally, we investigated the regions of the brain that are critical for object representation. Our results show distinct and overlapping areas in the ventral visual cortex for all three categories, with faces activating the ventral visual cortex inferiorly, especially centered on right fusiform gyrus, and chairs and planes activating more diffuse regions, overlapping with the superior part of face region and mainly located in middle occipital cortex and parietal areas. PMID:21254806

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.

Kit signaling inhibits the sphingomyelin-ceramide pathway through PLC gamma 1: implication in stem cell factor radioprotective effect.

PubMed

Maddens, Stéphane; Charruyer, Alexandra; Plo, Isabelle; Dubreuil, Patrice; Berger, Stuart; Salles, Bernard; Laurent, Guy; Jaffrézou, Jean-Pierre

2002-08-15

Previous studies demonstrated that Kit activation confers radioprotection. However, the mechanism by which Kit signaling interferes with cellular response to ionizing radiation (IR) has not been firmly established. Based on the role of the sphingomyelin (SM) cycle apoptotic pathway in IR-induced apoptosis, we hypothesized that one of the Kit signaling components might inhibit IR-induced ceramide production or ceramide-induced apoptosis. Results show that, in both Ba/F3 and 32D murine cell lines transfected with wild-type c-kit, stem cell factor (SCF) stimulation resulted in a significant reduction of IR-induced apoptosis and cytotoxicity, whereas DNA repair remained unaffected. Moreover, SCF stimulation inhibited IR-induced neutral sphingomyelinase (N-SMase) stimulation and ceramide production. The SCF inhibitory effect on SM cycle was not influenced by wortmannin, a phosphoinositide-3 kinase (PI3K) inhibitor. The SCF protective effect was maintained in 32D-KitYF719 cells in which the PI3K/Akt signaling pathway is abolished due to mutation in Kit docking site for PI3K. In contrast, phospholipase C gamma (PLC gamma) inhibition by U73122 totally restored IR-induced N-SMase stimulation, ceramide production, and apoptosis in Kit-activated cells. Moreover, SCF did not protect 32D-KitYF728 cells (lacking a functional docking site for PLC gamma 1), from IR-induced SM cycle. Finally, SCF-induced radioprotection of human CD34(+) bone marrow cells was also inhibited by U73122. Altogether, these results suggest that SCF radioprotection is due to PLC gamma 1-dependent negative regulation of IR-induced N-SMase stimulation. Beyond the scope of Kit-expressing cells, it suggests that PLC gamma 1 status could greatly influence the post-DNA damage cellular response to IR, and perhaps, to other genotoxic agents.

Active control of silver nanoparticles spacing using dielectrophoresis for surface-enhanced Raman scattering.

PubMed

Chrimes, Adam F; Khoshmanesh, Khashayar; Stoddart, Paul R; Kayani, Aminuddin A; Mitchell, Arnan; Daima, Hemant; Bansal, Vipul; Kalantar-zadeh, Kourosh

2012-05-01

We demonstrate an active microfluidic platform that integrates dielectrophoresis for the control of silver nanoparticles spacing, as they flow in a liquid channel. By careful control of the nanoparticles spacing, we can effectively increase the surface-enhanced Raman scattering (SERS) signal intensity based on augmenting the number of SERS-active hot-spots, while avoiding irreversible aggregation of the particles. The system is benchmarked using dipicolinate (2,6-pyridinedicarboxylic acid) (DPA), which is a biomarker of Bacillus anthracis. The validity of the results is discussed using several complementing characterization scenarios.

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.

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.

Space Commercialization

NASA Technical Reports Server (NTRS)

Martin, Gary L.

2011-01-01

A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

NewSpace: The Emerging Commercial Space Industry

NASA Technical Reports Server (NTRS)

Martin, Gary

2017-01-01

We are at a turning point in the history of space exploration and development, where new industries are being born to use space in non-traditional ways. Established state-run industrial space sector is no longer the only game in town; commercial space is becoming competitive. Many new entrepreneurial companies, such as SpaceX, Deep Space Industries, etc. are developing new markets, such as Orbital, Suborbital, and Deep Space. Together, government and private industry can facilitate the birth of this new industry. The U.S. national policy on commercial space is to develop a robust and competitive U.S. commercial space sector and to energize competitive domestic industries to participate in global markets. NASA can do this by purchasing and using commercial space capabilities and services; exploring the use of nontraditional arrangements for acquiring space capabilities and services; refraining from activities that preclude, discourage, or compete with commercial space activities; and pursuing opportunities to transfer some functions to the commercial space sector, where beneficial. Commercial space must be competitive, while the government has other priorities such as safety, jobs, etc.

Public choice economics and space policy: realising space tourism

NASA Astrophysics Data System (ADS)

Collins, Patrick

2001-03-01

Government space agencies have the statutory responsibility to suport the commercialisation of space activities. NASA's 1998 report "General Public Space Travel and Tourism" concluded that passenger space travel can start using already existing technology, and is likely to grow into the largest commercial activity in space: it is therefore greatly in taxpayers' economic interest that passenger space travel and accommodation industries should be developed. However, space agencies are doing nothing to help realise this — indeed, they are actively delaying it. This behaviour is predicted by 'public choice' economics, pioneered by Professors George Stigler and James Buchanan who received the 1982 and 1986 Nobel prizes for Economics, which views government organisations as primarily self-interested. The paper uses this viewpoint to discuss public and private roles in the coming development of a space tourism industry.

Multifunctional spaces in slum settlements and their relation to activity pattern case study of Kampung Sangkrah, Surakarta

NASA Astrophysics Data System (ADS)

Shobirin, Abyzhar; Ramadhanty, Almira Husna; Hardiana, Ana

2018-02-01

Surakarta is a rapidly urbanized city and it causes the limitation of the availability of land within its urban area. This entangled problem is resulting in the development of slum settlements that spread across the city. One of the slum concentration areas is located on Pepe riverbanks downstream area that belongs to Kampung Sangkrah administrative boundaries. Slum settlements are characterized as a densely-populated area lacking of, or absence of, open space. This condition forces slum inhabitants to effectively use their available spaces, even multi-functionally. This research aims to observe how slum inhabitants multi-functionally use the spaces around their houses and determine the typology of multifunctional space and also the factors that influence it. To understand this phenomenon, this research used activity pattern perspectives. The scope of observation covers in-house (internal) space utilizations and neighborhood-level (external) space utilization. The data used for this research were collected primarily through site observations and interviews, using sampling to conduct data collection for in-house activities and space utilization. The analysis was conducted using descriptive method qualitatively. The research concluded that there are three types of multifunctional space utilization within slum settlements, and the utilization of spaces, whether internal or external utilization also varies depending on the inhabitants' economic-related activities.

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.

ACOSS Fourteen (Active Control of Space Structures)

DTIC Science & Technology

1983-03-01

M ^^^——^^^^ ACOSS FOURTEEN (ACTIVE CONTROL OF SPACE STRUCTURES) Robert J . Benhabib Henry K. Flashner Frank C. Tung Contractor: TRW...PMJILUIJIJ.IIJIIIJI’I.I J I ! ’i-’-ummwmwMu», "»,-’■ m «mpiiw WJPWI» on UJ <_) O cc Q- (_1 a o a. oo I 5 < 3 in ai c 0 in LU c...1 S- s_ a: 1^3 >+- 𔃺 c ■ ^—v O) 0) OJ >—< ( J M - C r? s- s- T3 OO 0 E ■f— a. O S- +.) i i. 0) 0 OJ 03 c _a OJ cn =3 O e 3 01

Evaluating space weather forecasts of geomagnetic activity from a user perspective

NASA Astrophysics Data System (ADS)

Thomson, A. W. P.

2000-12-01

Decision Theory can be used as a tool for discussing the relative costs of complacency and false alarms with users of space weather forecasts. We describe a new metric for the value of space weather forecasts, derived from Decision Theory. In particular we give equations for the level of accuracy that a forecast must exceed in order to be useful to a specific customer. The technique is illustrated by simplified example forecasts for global geomagnetic activity and for geophysical exploration and power grid management in the British Isles.

Luminescent and scintillation properties of Lu3Al5O12:Sc single crystal and single crystalline films

NASA Astrophysics Data System (ADS)

Zorenko, Y.; Gorbenko, V.; Voznyak, T.; Savchyn, V.; Nizhankovskiy, S.; Dan'ko, A.; Puzikov, V.; Laguta, V.; Mares, J. A.; Nikl, M.; Nejezchleb, K.; Batentschuk, M.; Winnacker, A.

2012-10-01

The work is dedicated to growth by the liquid phase epitaxy method and study of the luminescence and scintillation properties of Sc3+ doped single crystalline films (SCF) of Lu3Al5O12 (LuAG) garnet. The scintillation properties of SCF are compared with single crystal (SC) analogues grown by the Horizontal Direct Crystallization and Czochralski methods. We consider the dependence of intensity of the Sc3+ emission in LuAG host on the activator concentration and influence of flux contamination on the light yield (LY) of the Sc3+ luminescence in LuAG:Sc SCF with respect to their SC counterparts and the reference YAP:Ce scintillator. From the NMR investigations of LuAG:Sc SCF we confirm the substitution by Sc3+ ions both the octahedral and dodecahedral positions of LuAG host and formation of the ScAl and ScLu related emission centers, respectively. We also show that the luminescence spectrum in the UV range and decay kinetics of LuAG:Sc SCF can be effectively tuned by changing the scandium content.

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…

Generating GPS activity spaces that shed light upon the mobility habits of older adults: a descriptive analysis.

PubMed

Hirsch, Jana A; Winters, Meghan; Clarke, Philippa; McKay, Heather

2014-12-12

Measuring mobility is critical for understanding neighborhood influences on older adults' health and functioning. Global Positioning Systems (GPS) may represent an important opportunity to measure, describe, and compare mobility patterns in older adults. We generated three types of activity spaces (Standard Deviation Ellipse, Minimum Convex Polygon, Daily Path Area) using GPS data from 95 older adults in Vancouver, Canada. Calculated activity space areas and compactness were compared across sociodemographic and resource characteristics. Area measures derived from the three different approaches to developing activity spaces were highly correlated. Participants who were younger, lived in less walkable neighborhoods, had a valid driver's license, had access to a vehicle, or had physical support to go outside of their homes had larger activity spaces. Mobility space compactness measures also differed by sociodemographic and resource characteristics. This research extends the literature by demonstrating that GPS tracking can be used as a valuable tool to better understand the geographic mobility patterns of older adults. This study informs potential ways to maintain older adult independence by identifying factors that influence geographic mobility.

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.

UK technical activities associated with the return to Earth of the MIR space station

NASA Astrophysics Data System (ADS)

Crowther, Richard; Tremayne-Smith, Richard

2002-11-01

The British National Space Centre (BNSC) acts as the focus in the United Kingdom (UK) for space-related activities. With the anticipated return to Earth of the MIR space station, BNSC established a group of technical experts to consider the associated implications for the UK, and to address both national and international activities relating to the planned de-orbit. In particular, the risk to the UK of an uncontrolled re-entry was considered in contingency planning and the means for the provision of accurate information to the public and media were established to ensure balanced view of the potential hazards that MIR posed to persons and property on the ground. The MIR de-orbit was exemplary, both in terms of the technical activities of the Rosaviakosmos and the safe disposal of MIR in the Pacific, and in relation to the open and effective communication between agencies and the positive reporting by the media.

Prevention of decompression sickness during extravehicular activity in space: a review.

PubMed

Tokumaru, O

1997-12-01

Extended and more frequent extravehicular activity (EVA) is planned in NASA's future space programs. The more EVAs are conducted, the higher the incidence of decompression sickness (DCS) that is anticipated. Since Japan is also promoting the Space Station Freedom project with NASA, DCS during EVA will be an inevitable complication. The author reviewed the pathophysiology of DCS and detailed four possible ways of preventing decompression sickness during EVA in space: (1) higher pressure suit technology; (2) preoxygenation/prebreathing; (3) staged decompression; and (4) habitat or vehicle pressurization. Among these measures, development of zero-prebreathe higher pressure suit technology seems most ideal, but because of economic and technical reasons and in cases of emergency, other methods must also be improved. Unsolved problems like repeated decompression or oxygen toxicity were also listed.

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.

EVA 4 activity on Flight Day 7 to service the Hubble Space Telescope

NASA Image and Video Library

1997-02-17

STS082-711-067 (11-21 Feb. 1997) --- Astronaut Gregory J. Harbaugh, mission specialist, floats horizontally in the cargo bay of the Earth-orbiting Space Shuttle Discovery, backdropped against its giant temporary passenger, the Hubble Space Telescope (HST). Harbaugh, sharing this space walking activity with astronaut Joseph R. Tanner (out of frame), is actually recognizable through his helmet visor in the 70mm frame. He is near the Second Axial Carrier (SAC), Axial Scientific Instrument Protection Enclosure (ASIPE). STS-82 marked the first flight of the exit airlock, partially visible at bottom edge of photo.

Marshall Space Flight Center Technology Capabilities for Use in Space Situational Awareness Activities

NASA Technical Reports Server (NTRS)

Gagliano, Larry; McLeod, Todd; Hovater, Mary A.

2017-01-01

Marshall performs research, integrates information, matures technologies, and enhances science to bring together a diverse portfolio of products and services of interest for Space Situational Awareness (SSA) and Space Asset Management (SAM), all of which can be accessed through partnerships with Marshall. Integrated Space Situational Awareness and Asset Management (ISSAAM) is an initiative of NASA's Marshall Space Flight Center to improve space situational awareness and space asset management through technical innovation, collaboration, and cooperation with U.S. Government agencies and the global space community. Marshall Space Flight Center provides solutions for complex issues with in-depth capabilities, a broad range of experience, and expertise unique in the world, and all available in one convenient location. NASA has longstanding guidelines that are used to assess space objects. Specifically, Marshall Space Flight Center has the capabilities, facilities and expertise to address the challenges that space objects, such as near-Earth objects (NEO) or Orbital Debris pose. ISSAAM's three pronged approach brings together vital information and in-depth tools working simultaneously toward examining the complex problems encountered in space situational awareness. Marshall's role in managing, understanding and planning includes many projects grouped under each prong area: Database/Analyses/Visualization; Detection/Tracking/ Mitigation/Removal. These are not limited to those listed below.

NIST activities in support of space-based radiometric remote sensing

NASA Astrophysics Data System (ADS)