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Sample records for matrix subunit compaction

  1. Elongated polyproline motifs facilitate enamel evolution through matrix subunit compaction.

    PubMed

    Jin, Tianquan; Ito, Yoshihiro; Luan, Xianghong; Dangaria, Smit; Walker, Cameron; Allen, Michael; Kulkarni, Ashok; Gibson, Carolyn; Braatz, Richard; Liao, Xiubei; Diekwisch, Thomas G H

    2009-12-01

    Vertebrate body designs rely on hydroxyapatite as the principal mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth-bearing jaws, facilitating rapid movement and efficient predation. Biological mineralization and skeletal growth are frequently accomplished through proteins containing polyproline repeat elements. Through their well-defined yet mobile and flexible structure polyproline-rich proteins control mineral shape and contribute many other biological functions including Alzheimer's amyloid aggregation and prolamine plant storage. In the present study we have hypothesized that polyproline repeat proteins exert their control over biological events such as mineral growth, plaque aggregation, or viscous adhesion by altering the length of their central repeat domain, resulting in dramatic changes in supramolecular assembly dimensions. In order to test our hypothesis, we have used the vertebrate mineralization protein amelogenin as an exemplar and determined the biological effect of the four-fold increased polyproline tandem repeat length in the amphibian/mammalian transition. To study the effect of polyproline repeat length on matrix assembly, protein structure, and apatite crystal growth, we have measured supramolecular assembly dimensions in various vertebrates using atomic force microscopy, tested the effect of protein assemblies on crystal growth by electron microscopy, generated a transgenic mouse model to examine the effect of an abbreviated polyproline sequence on crystal growth, and determined the structure of polyproline repeat elements using 3D NMR. Our study shows that an increase in PXX/PXQ tandem repeat motif length results (i) in a compaction of protein matrix subunit dimensions, (ii) reduced conformational variability, (iii) an increase in polyproline II helices, and (iv) promotion of apatite crystal length. Together, these findings establish a direct relationship between polyproline tandem repeat fragment

  2. Elongated Polyproline Motifs Facilitate Enamel Evolution through Matrix Subunit Compaction

    PubMed Central

    Luan, Xianghong; Dangaria, Smit; Walker, Cameron; Allen, Michael; Kulkarni, Ashok; Gibson, Carolyn; Braatz, Richard; Liao, Xiubei; Diekwisch, Thomas G. H.

    2009-01-01

    Vertebrate body designs rely on hydroxyapatite as the principal mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth-bearing jaws, facilitating rapid movement and efficient predation. Biological mineralization and skeletal growth are frequently accomplished through proteins containing polyproline repeat elements. Through their well-defined yet mobile and flexible structure polyproline-rich proteins control mineral shape and contribute many other biological functions including Alzheimer's amyloid aggregation and prolamine plant storage. In the present study we have hypothesized that polyproline repeat proteins exert their control over biological events such as mineral growth, plaque aggregation, or viscous adhesion by altering the length of their central repeat domain, resulting in dramatic changes in supramolecular assembly dimensions. In order to test our hypothesis, we have used the vertebrate mineralization protein amelogenin as an exemplar and determined the biological effect of the four-fold increased polyproline tandem repeat length in the amphibian/mammalian transition. To study the effect of polyproline repeat length on matrix assembly, protein structure, and apatite crystal growth, we have measured supramolecular assembly dimensions in various vertebrates using atomic force microscopy, tested the effect of protein assemblies on crystal growth by electron microscopy, generated a transgenic mouse model to examine the effect of an abbreviated polyproline sequence on crystal growth, and determined the structure of polyproline repeat elements using 3D NMR. Our study shows that an increase in PXX/PXQ tandem repeat motif length results (i) in a compaction of protein matrix subunit dimensions, (ii) reduced conformational variability, (iii) an increase in polyproline II helices, and (iv) promotion of apatite crystal length. Together, these findings establish a direct relationship between polyproline tandem repeat fragment

  3. Squeeze flow and compaction behavior of toughened polyimide matrix composites

    NASA Technical Reports Server (NTRS)

    Lee, Byung Lip; Pater, R.; Soucek, M. D.

    1991-01-01

    The main emphasis was placed upon the squeeze flow and compaction behavior of the Lewis Research Center (LaRC) research project series polyimide matrix composites. The measurement of squeeze film flow behavior was performed by a plastometer which monitors the change of thickness of a prepreg specimen laid between two parallel plates under the specified temperature and pressure history. A critical evaluation of the plastometer data was attempted by examining the morphology of the specimen at various points during the squeeze flow. The effects of crosslinks (Mc) of resin, imidization (B-ataging) condition, and pressure on the squeeze flow behavior were examined. Results are given.

  4. Chondrites: The Compaction of Fine Matrix and Matrix-like Chondrule Rims

    NASA Astrophysics Data System (ADS)

    Wasson, J. T.

    1995-09-01

    Primitive chondritic meteorites mainly consist of chondrules, sulfide+/-metal, and fine-grained matrix. The most unequilibrated chondrites preserve in their phase compositions and, to a lesser degree, their textures, many details about processes that occurred in the solar nebula. On the other hand, much of the textural evidence records processes that occurred in or on the parent body. I suggest that the low-porosity of chondrule matrix and matrix-like rims reflects compaction processes that occurred in asteroid-size bodies, and that neither matrix lumps nor compact matrix-like rims on chondrules could have achieved their observed low porosities in the solar nebula. Recent theoretical studies by Donn and Meakin (1) and Chokshi et al. (2) have concluded that grain-grain sticking in the solar nebula mainly produces fluffy structures having very high porosities (probably >>50%). If these structures grow large enough, they can provide an aerogel-like matrix that can trap chondrules as well as metal and sulfide grains, and thus form suitable precursors of chondritic meteorites. However, the strength of any such structure formed in the solar nebula must be a trivial fraction of that required to survive passage through the Earth's atmosphere in order to fall as a meteorite. The best evidence of accretionary structures appears to be that reported by Metzler et al. (3). They made SEM images of entire thin sections of CM chondrites, and showed that, in the best preserved chondrites, rims are present on all entitities--on chondrules, chondrule fragments, refractory inclusions, etc. A study by Krot and Wasson (4) shows a more complex situation in ordinary chondrites. Although matrix is common, a sizable fraction of chondrules are not surrounded by matrix-like rims. As summarized by Rubin and Krot (1995), there are reports of small textural and compositional differences between matrix lumps and mean matrix-like chondrule rims, but there is so much overlap in properties between

  5. Evaluation of roll compaction as a preparation method for hydroxypropyl cellulose-based matrix tablets

    PubMed Central

    Jeon, Imjak; Gilli, Tiziana; Betz, Gabriele

    2011-01-01

    Roll compaction was applied for the preparation of hydroxypropyl cellulose (HPC)-based sustained-release matrix tablets. Matrix tablets made via roll compaction exhibited higher dosage uniformity and faster drug release than direct-compacted tablets. HPC viscosity grade, roll pressure, and milling speed affected tablet properties significantly. Roll compaction seems to be an adequate granulation method for the preparation of HPC-based matrix tablets due to the simplicity of the process, less handling difficulty from HPC tackiness as well as easier particle size targeting. Selecting the optimum ratio of plastic excipients and the particle size of starting materials can however be critical issues in this method. PMID:21687348

  6. T Cell Receptor Engagement Triggers Its CD3ε and CD3ζ Subunits to Adopt a Compact, Locked Conformation

    PubMed Central

    Risueño, Ruth M.; Schamel, Wolfgang W. A.; Alarcón, Balbino

    2008-01-01

    How the T cell antigen receptor (TCR) discriminates between molecularly related peptide/Major Histocompatibility Complex (pMHC) ligands and converts this information into different possible signaling outcomes is still not understood. One current model proposes that strong pMHC ligands, but not weak ones, induce a conformational change in the TCR. Evidence supporting this comes from a pull-down assay that detects ligand-induced binding of the TCR to the N-terminal SH3 domain of the adapter protein Nck, and also from studies with a neoepitope-specific antibody. Both methods rely on the exposure of a polyproline sequence in the CD3ε subunit of the TCR, and neither indicates whether the conformational change is transmitted to other CD3 subunits. Using a protease-sensitivity assay, we now show that the cytoplasmic tails of CD3ε and CD3ζ subunits become fully protected from degradation upon TCR triggering. These results suggest that the TCR conformational change is transmitted to the tails of CD3ε and CD3ζ, and perhaps all CD3 subunits. Furthermore, the resistance to protease digestion suggests that CD3 cytoplasmic tails adopt a compact structure in the triggered TCR. These results are consistent with a model in which transduction of the conformational change induced upon TCR triggering promotes condensation and shielding of the CD3 cytoplasmic tails. PMID:18320063

  7. Compression and compaction properties of plasticised high molecular weight hydroxypropylmethylcellulose (HPMC) as a hydrophilic matrix carrier.

    PubMed

    Hardy, I J; Cook, W G; Melia, C D

    2006-03-27

    The compression and compaction properties of plasticised high molecular weight USP2208 HPMC were investigated with the aim of improving tablet formation in HPMC matrices. Experiments were conducted on binary polymer-plasticiser mixtures containing 17 wt.% plasticiser, and on a model hydrophilic matrix formulation. A selection of common plasticisers, propylene glycol (PG) glycerol (GLY), dibutyl sebacate (DBS) and triacetin (TRI), were chosen to provide a range of plasticisation efficiencies. T(g) values of binary mixtures determined by Dynamic Mechanical Thermal Analysis (DMTA) were in rank order PG>GLY>DBS>TRI>unplasticised HPMC. Mean yield pressure, strain rate sensitivity (SRS) and plastic compaction energy were measured during the compression process, and matrix properties were monitored by tensile strength and axial expansion post-compression. Compression of HPMC:PG binary mixtures resulted in a marked reduction in mean yield pressure and a significant increase in SRS, suggesting a classical plasticisation of HPMC analogous to that produced by water. The effect of PG was also reflected in matrix properties. At compression pressures below 70 MPa, compacts had greater tensile strength than those from native polymer, and over the range 35 and 70 MPa, lower plastic compaction values showed that less energy was required to produce the compacts. Axial expansion was also reduced. Above 70 MPa tensile strength was limited to 3 MPa. These results suggest a useful improvement of HPMC compaction and matrix properties by PG plasticisation, with lowering of T(g) resulting in improved deformation and internal bonding. These effects were also detectable in the model formulation containing a minimal polymer content for an HPMC matrix. Other plasticisers were largely ineffective, matrix strength was poor and axial expansion high. The hydrophobic plasticisers (DBS, TRI) reduced yield pressure substantially, but were poor plasticisers and showed compaction mechanisms that could

  8. Adjuvant effect of the human metapneumovirus (HMPV) matrix protein in HMPV subunit vaccines.

    PubMed

    Aerts, Laetitia; Rhéaume, Chantal; Carbonneau, Julie; Lavigne, Sophie; Couture, Christian; Hamelin, Marie-Ève; Boivin, Guy

    2015-04-01

    The human metapneumovirus (HMPV) fusion (F) protein is the most immunodominant protein, yet subunit vaccines containing only this protein do not confer complete protection. The HMPV matrix (M) protein induces the maturation of antigen-presenting cells in vitro. The inclusion of the M protein into an F protein subunit vaccine might therefore provide an adjuvant effect. We administered the F protein twice intramuscularly, adjuvanted with alum, the M protein or both, to BALB/c mice at 3 week intervals. Three weeks after the boost, mice were infected with HMPV and monitored for 14 days. At day 5 post-challenge, pulmonary viral titres, histopathology and cytokine levels were analysed. Mice immunized with F+alum and F+M+alum generated significantly more neutralizing antibodies than mice immunized with F only [titres of 47 ± 7 (P<0.01) and 147 ± 13 (P<0.001) versus 17 ± 2]. Unlike F only [1.6 ± 0.5 × 10(3) TCID50 (g lung)(-1)], pulmonary viral titres in mice immunized with F+M and F+M+alum were undetectable. Mice immunized with F+M presented the most important reduction in pulmonary inflammation and the lowest T-helper Th2/Th1 cytokine ratio. In conclusion, addition of the HMPV-M protein to an F protein-based vaccine modulated both humoral and cellular immune responses to subsequent infection, thereby increasing the protection conferred by the vaccine.

  9. SEPARATION OF NEWLY FORMED BONE FROM OLDER COMPACT BONE REVEALS CLEAR COMPOSITIONAL DIFFERENCES IN BONE MATRIX

    PubMed Central

    Midura, Ronald J.; Midura, Sharon B.; Su, Xiaowei; Gorski, Jeffrey P.

    2011-01-01

    In long bone diaphyses, woven bone forms first and then transitions into a more mineralized compact bone tissue. Prior evidence suggests that the non-collagenous protein composition of woven bone may be distinct from that of more mature bone tissue, particularly with respect to a diverse group of phosphorylated, extracellular matrix proteins. To critically test this hypothesis, we developed an in situ approach to isolate newly formed bone from more mature bone within the same long bone, and combine this anatomical approach with Western blotting to make relative comparisons of 7 phosphorylated matrix proteins important for bone physiology and biomineralization. Interestingly, 75 kDa bone sialoprotein (BSP), 63 kDa osteopontin, and the 75 kDa form of bone acidic glycoprotein-75 (BAG-75) were enriched in primary bone as opposed to more mature cortical bone, while osteonectin, fetuin A, matrix extracellular phosphoglycoprotein (MEPE) and dentin matrix protein-1 (DMP-1) appeared to be equally distributed between these two bone tissue compartments. Analyses also revealed the presence of larger sized forms of osteopontin (and to a lesser degree BSP) mostly in newly formed bone, while larger forms of BAG-75 were mostly detected in more mature cortical bone. Smaller sized forms of DMP-1 and BAG-75 were detected in both newly formed and more mature bone tissue extracts, and they are likely the result of proteolytic processing in vivo. Intact DMP-1 (97 kDa) was only detected in unmineralized matrix extracts. These findings indicate that newly formed bone exhibits a non-collagenous matrix protein composition distinct from that of more mature compact bone even within the same long bone, and suggest that the temporal fate of individual non-collagenous proteins is variable in growing bone. PMID:21958842

  10. Analysis of Natural Graphite, Synthetic Graphite, and Thermosetting Resin Candidates for Use in Fuel Compact Matrix

    SciTech Connect

    Trammell, Michael P; Pappano, Peter J

    2011-09-01

    The AGR-1 and AGR-2 compacting process involved overcoating TRISO particles and compacting them in a steel die. The overcoating step is the process of applying matrix to the OPyC layer of TRISO particles in a rotating drum in order to build up an overcoat layer of desired thickness. The matrix used in overcoating is a mixture of natural graphite, synthetic graphite, and thermosetting resin in the ratio, by weight, of 64:16:20. A wet mixing process was used for AGR-1 and AGR-2, in that the graphites and resin were mixed in the presence of ethyl alcohol. The goal of the wet mixing process was to 'resinate' the graphite particles, or coat each individual graphite particle with a thin layer of resin. This matrix production process was similar to the German, Chinese, Japanese, and South African methods, which also use various amount of solvent during mixing. See Appendix 1 for information on these countries matrix production techniques. The resin used for AGR-1 and AGR-2 was provided by Hexion, specifically Hexion grade Durite SC1008. Durite SC1008 is a solvated (liquid) resole phenolic resin. A resole resin does not typically have a hardening agent added. The major constituent of SC1008 is phenol, with minor amounts of formaldehyde. Durite SC1008 is high viscosity, so additional ethyl alcohol was added during matrix production in order to reduce its viscosity and enhance graphite particle resination. The current compacting scale up plan departs from a wet mixing process. The matrix production method specified in the scale up plan is a co-grinding jet mill process where powdered phenolic resin and graphite are all fed into a jet mill at the same time. Because of the change in matrix production style, SC1008 cannot be used in the jet milling process because it is a liquid. The jet milling/mixing process requires that a suite of solid or powdered resins be investigated. The synthetic graphite used in AGR-1 and AGR-2 was provided by SGL Carbon, grade KRB2000. KRB2000 is a

  11. Exploiting the speckle-correlation scattering matrix for a compact reference-free holographic image sensor

    NASA Astrophysics Data System (ADS)

    Lee, Kyeoreh; Park, Yongkeun

    2016-10-01

    The word `holography' means a drawing that contains all of the information for light--both amplitude and wavefront. However, because of the insufficient bandwidth of current electronics, the direct measurement of the wavefront of light has not yet been achieved. Though reference-field-assisted interferometric methods have been utilized in numerous applications, introducing a reference field raises several fundamental and practical issues. Here we demonstrate a reference-free holographic image sensor. To achieve this, we propose a speckle-correlation scattering matrix approach; light-field information passing through a thin disordered layer is recorded and retrieved from a single-shot recording of speckle intensity patterns. Self-interference via diffusive scattering enables access to impinging light-field information, when light transport in the diffusive layer is precisely calibrated. As a proof-of-concept, we demonstrate direct holographic measurements of three-dimensional optical fields using a compact device consisting of a regular image sensor and a diffusor.

  12. Exploiting the speckle-correlation scattering matrix for a compact reference-free holographic image sensor

    PubMed Central

    Lee, KyeoReh; Park, YongKeun

    2016-01-01

    The word ‘holography' means a drawing that contains all of the information for light—both amplitude and wavefront. However, because of the insufficient bandwidth of current electronics, the direct measurement of the wavefront of light has not yet been achieved. Though reference-field-assisted interferometric methods have been utilized in numerous applications, introducing a reference field raises several fundamental and practical issues. Here we demonstrate a reference-free holographic image sensor. To achieve this, we propose a speckle-correlation scattering matrix approach; light-field information passing through a thin disordered layer is recorded and retrieved from a single-shot recording of speckle intensity patterns. Self-interference via diffusive scattering enables access to impinging light-field information, when light transport in the diffusive layer is precisely calibrated. As a proof-of-concept, we demonstrate direct holographic measurements of three-dimensional optical fields using a compact device consisting of a regular image sensor and a diffusor. PMID:27796290

  13. Identification of Integrin β Subunit Mutations That Alter Affinity for Extracellular Matrix Ligand*

    PubMed Central

    Kendall, Timmy; Mukai, Leona; Jannuzi, Alison L.; Bunch, Thomas A.

    2011-01-01

    We examined over 50 mutations in the Drosophila βPS integrin subunit that alter integrin function in situ for their ability to bind a soluble monovalent ligand, TWOW-1. Surprisingly, very few of the mutations, which were selected for conditional lethality in the fly, reduce the ligand binding ability of the integrin. The most prevalent class of mutations activates the integrin heterodimer. These findings emphasize the importance of integrin affinity regulation and point out how molecular interactions throughout the integrin molecule are important in keeping the integrin in a low affinity state. Mutations strongly support the controversial deadbolt hypothesis, where the CD loop in the β tail domain acts to restrain the I domain in the inactive, bent conformation. Site-directed mutations in the cytoplasmic domains of βPS and αPS2C reveal different effects on ligand binding from those observed for αIIbβ3 integrins and identify for the first time a cytoplasmic cysteine residue, conserved in three human integrins, as being important in affinity regulation. In the fly, we find that genetic interactions of the βPS mutations with reduction in talin function are consistent with the integrin affinity differences measured in cells. Additionally, these genetic interactions report on increased and decreased integrin functions that do not result in affinity changes in the PS2C integrin measured in cultured cells. PMID:21757698

  14. Quasi-disjoint pentadiagonal matrix systems for the parallelization of compact finite-difference schemes and filters

    NASA Astrophysics Data System (ADS)

    Kim, Jae Wook

    2013-05-01

    This paper proposes a novel systematic approach for the parallelization of pentadiagonal compact finite-difference schemes and filters based on domain decomposition. The proposed approach allows a pentadiagonal banded matrix system to be split into quasi-disjoint subsystems by using a linear-algebraic transformation technique. As a result the inversion of pentadiagonal matrices can be implemented within each subdomain in an independent manner subject to a conventional halo-exchange process. The proposed matrix transformation leads to new subdomain boundary (SB) compact schemes and filters that require three halo terms to exchange with neighboring subdomains. The internode communication overhead in the present approach is equivalent to that of standard explicit schemes and filters based on seven-point discretization stencils. The new SB compact schemes and filters demand additional arithmetic operations compared to the original serial ones. However, it is shown that the additional cost becomes sufficiently low by choosing optimal sizes of their discretization stencils. Compared to earlier published results, the proposed SB compact schemes and filters successfully reduce parallelization artifacts arising from subdomain boundaries to a level sufficiently negligible for sophisticated aeroacoustic simulations without degrading parallel efficiency. The overall performance and parallel efficiency of the proposed approach are demonstrated by stringent benchmark tests.

  15. The PB2 Subunit of the Influenza A Virus RNA Polymerase Is Imported into the Mitochondrial Matrix

    PubMed Central

    Long, Joshua C. D.

    2016-01-01

    ABSTRACT The polymerase basic 2 (PB2) subunit of the RNA polymerase complex of seasonal human influenza A viruses has been shown to localize to the mitochondria. Various roles, including the regulation of apoptosis and innate immune responses to viral infection, have been proposed for mitochondrial PB2. In particular, PB2 has been shown to inhibit interferon expression by associating with the mitochondrial antiviral signaling (MAVS) protein, which acts downstream of RIG-I and MDA-5 in the interferon induction pathway. However, in spite of a growing body of literature on the potential roles of mitochondrial PB2, the exact location of PB2 in mitochondria has not been determined. Here, we used enhanced ascorbate peroxidase (APEX)-tagged PB2 proteins and electron microscopy to study the localization of PB2 in mitochondria. We found that PB2 is imported into mitochondria, where it localizes to the mitochondrial matrix. We also demonstrated that MAVS is not required for the import of PB2 into mitochondria by showing that PB2 associates with mitochondria in MAVS knockout mouse embryo fibroblasts. Instead, we found that amino acid residue 9 in the N-terminal mitochondrial targeting sequence is a determinant of the mitochondrial import of PB2, differentiating the localization of PB2 of human from that of avian influenza A virus strains. We also showed that a virus encoding nonmitochondrial PB2 is attenuated in mouse embryonic fibroblasts (MEFs) compared with an isogenic virus encoding mitochondrial PB2, in a MAVS-independent manner, suggesting a role for PB2 within the mitochondrial matrix. This work extends our understanding of the interplay between influenza virus and mitochondria. IMPORTANCE The PB2 subunit of the influenza virus RNA polymerase is a major determinant of viral pathogenicity. However, the molecular mechanisms of how PB2 determines pathogenicity remain poorly understood. PB2 associates with mitochondria and inhibits the function of the mitochondrial

  16. Matrix Extension Study: Validation of the Compact Dry CF Method for Enumeration of Total Coliform Bacteria in Selected Foods.

    PubMed

    Mizuochi, Shingo; Nelson, Maria; Baylis, Chris; Green, Becky; Jewell, Keith; Monadjemi, Farinaz; Chen, Yi; Salfinger, Yvonne; Fernandez, Maria Cristina

    2016-01-01

    The Compact Dry "Nissui" CF method, Performance Tested Method(SM) 110401, was originally certified for enumeration of coliform bacteria by the AOAC Research Institute Performance Tested Methods(SM) program for raw meat products. Compact Dry CF is a ready-to-use dry media sheet, containing a cold-soluble gelling agent, a chromogenic medium, and selective agents, which are rehydrated by adding 1 mL of diluted sample. Coliform bacteria produce blue/blue-green colonies on the Compact Dry CF, allowing a coliform colony count to be determined in the sample after 24 ± 2 h incubation. A validation study was organized by Campden BRI (formerly Campden and Chorleywood Food Research Association Technology, Ltd), Chipping Campden, United Kingdom, to extend the method's claim to include cooked chicken, fresh bagged prewashed shredded iceberg lettuce, frozen fish, milk powder, and pasteurized 2% milk. Campden BRI collected single-laboratory data for cooked chicken, lettuce, frozen fish, and milk powder, whereas a multilaboratory study was conducted on pasteurized milk. Thirteen laboratories participated in the interlaboratory study. The Compact Dry CF method was compared to ISO 4832:2006 "Microbiology of food and animal feeding stuffs-Horizontal method for the enumeration of coliforms-Colony-count technique," the current version at the time this study was conducted. Each matrix was evaluated at either four or five contamination levels of coliform bacteria (including an uncontaminated level). After logarithmic transformation of counts at each level, the data for pasteurized whole milk were analyzed for sr, sR, RSDr, and RSDR. Regression analysis was also performed and r(2) was reported. Mean difference between methods with 95% confidence interval (CI) was calculated. A log10 range of -0.5 to 0.5 for the CI was used as the acceptance criterion to establish significant statistical difference between methods. In the single-laboratory evaluation (for cooked chicken, lettuce, frozen

  17. Characterization of B- and C-type low molecular weight glutenin subunits by electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry.

    PubMed

    Muccilli, Vera; Cunsolo, Vincenzo; Saletti, Rosaria; Foti, Salvatore; Masci, Stefania; Lafiandra, Domenico

    2005-02-01

    Low molecular weight glutenin subunits (LMW-GS) are typically subdivided into three groups, according to their molecular weights and isoelectric points, namely the B-, C-, and D groups. Enriched B- and C-type LMW-GS fractions extracted from the bread wheat cultivar Chinese Spring were characterized using high performance liquid chromatography (HPLC) directly interfaced with electrospray ionization mass spectrometry and HPLC coupled off-line with matrix-assisted laser desorption/ionization mass spectrometry, in order to ascertain the number and relative molecular masses of the components present in each fraction and determine the number of cysteine residues. About 70 components were detected in each of the fractions examined by the combined use of these two techniques, with 18 components common to both fractions. Analysis of the fractions after alkylation with 4-vinylpyridine allowed determination of the number of the cysteines present in about 40 subunits. The proteins detected were tentatively classified based on the relative molecular masses and number of cysteine residues. Cross-contamination was found in both B- and C- fractions, along with the presence of D-type LMW-GS. The two fractions also contained unexpected components, probably lipid transfer proteins and omega-gliadins. The presence of extensive microheterogeneity was suggested by the detection of several co-eluting proteins with minor differences in their molecular masses.

  18. Near-infrared spectroscopic analysis of the breaking force of extended-release matrix tablets prepared by roller-compaction: influence of plasticizer levels and sintering temperature.

    PubMed

    Dave, Vivek S; Fahmy, Raafat M; Hoag, Stephen W

    2015-06-01

    The aim of this study was to investigate the feasibility of near-infrared (NIR) spectroscopy for the determination of the influence of sintering temperature and plasticizer levels on the breaking force of extended-release matrix tablets prepared via roller-compaction. Six formulations using theophylline as a model drug, Eudragit® RL PO or Eudragit® RS PO as a matrix former and three levels of TEC (triethyl citrate) as a plasticizer were prepared. The powder blend was roller compacted using a fixed roll-gap of 1.5 mm, feed screw speed to roller speed ratio of 5:1 and roll pressure of 4 MPa. The granules, after removing fines, were compacted into tablets on a Stokes B2 rotary tablet press at a compression force of 7 kN. The tablets were thermally treated at different temperatures (Room Temperature, 50, 75 and 100 °C) for 5 h. These tablets were scanned in reflectance mode in the wavelength range of 400-2500 nm and were evaluated for breaking force. Tablet breaking force significantly increased with increasing plasticizer levels and with increases in the sintering temperature. An increase in tablet hardness produced an upward shift (increase in absorbance) in the NIR spectra. The principle component analysis (PCA) of the spectra was able to distinguish samples with different plasticizer levels and sintering temperatures. In addition, a 9-factor partial least squares (PLS) regression model for tablets containing Eudragit® RL PO had an r(2) of 0.9797, a standard error of calibration of 0.6255 and a standard error of cross validation (SECV) of 0.7594. Similar analysis of tablets containing Eudragit® RS PO showed an r(2) of 0.9831, a standard error of calibration of 0.9711 and an SECV of 1.192.

  19. Efficacy of a non-updated, Matrix-C-based equine influenza subunit-tetanus vaccine following Florida sublineage clade 2 challenge

    PubMed Central

    Pouwels, H. G. W.; Van de Zande, S. M. A.; Horspool, L. J. I.; Hoeijmakers, M. J. H.

    2014-01-01

    Assessing the ability of current equine influenza vaccines to provide cross-protection against emerging strains is important. Horses not vaccinated previously and seronegative for equine influenza based on haemagglutination inhibition (HI) assay were assigned at random to vaccinated (n=7) or non-vaccinated (control, n=5) groups. Vaccination was performed twice four weeks apart with a 1 ml influenza subunit (A/eq/Prague/1/56, A/eq/Newmarket/1/93, A/eq/Newmarket/2/93), tetanus toxoid vaccine with Matrix-C adjuvant (EquilisPrequenza Te). All the horses were challenged individually by aerosol with A/eq/Richmond/1/07 three weeks after the second vaccination. Rectal temperature, clinical signs, serology and virus excretion were monitored for 14 days after challenge. There was no pain at the injection site or increases in rectal temperature following vaccination. Increases in rectal temperature and characteristic clinical signs were recorded in the control horses. Clinical signs were minimal in vaccinated horses. Clinical (P=0.0345) and total clinical scores (P=0.0180) were significantly lower in the vaccinated than in the control horses. Vaccination had a significant effect on indicators of viraemia – the extent (P=0.0006) and duration (P=<0.0001) of virus excretion and the total amount of virus excreted (AUC, P=0.0006). Vaccination also had a significant effect (P=0.0017) on whether a horse was positive or negative for virus excretion during the study. Further research is needed to fully understand the specific properties of this vaccine that may contribute to its cross-protective capacity. PMID:24795071

  20. Role of the Emp Pilus Subunits of Enterococcus faecium in Biofilm Formation, Adherence to Host Extracellular Matrix Components, and Experimental Infection

    PubMed Central

    Montealegre, Maria Camila; Singh, Kavindra V.; Somarajan, Sudha R.; Yadav, Puja; Chang, Chungyu; Spencer, Robert; Sillanpää, Jouko; Ton-That, Hung

    2016-01-01

    Enterococcus faecium is an important cause of hospital-associated infections, including urinary tract infections (UTIs), bacteremia, and infective endocarditis. Pili have been shown to play a role in the pathogenesis of Gram-positive bacteria, including E. faecium. We previously demonstrated that a nonpiliated ΔempABC::cat derivative of E. faecium TX82 was attenuated in biofilm formation and in a UTI model. Here, we studied the contributions of the individual pilus subunits EmpA, EmpB, and EmpC to pilus architecture, biofilm formation, adherence to extracellular matrix (ECM) proteins, and infection. We identified EmpA as the tip of the pili and found that deletion of empA reduced biofilm formation to the same level as deletion of the empABC operon, a phenotype that was restored by reconstituting in situ the empA gene. Deletion of empB also caused a reduction in biofilm, while EmpC was found to be dispensable. Significant reductions in adherence to fibrinogen and collagen type I were observed with deletion of empA and empB, while deletion of empC had no adherence defect. Furthermore, we showed that each deletion mutant was significantly attenuated in comparison to the isogenic parental strain, TX82, in a mixed-inoculum UTI model (P < 0.001 to 0.048), that reconstitution of empA restored virulence in the UTI model, and that deletion of empA also resulted in attenuation in an infective endocarditis model (P = 0.0088). Our results indicate that EmpA and EmpB, but not EmpC, contribute to biofilm and adherence to ECM proteins; however, all the Emp pilins are important for E. faecium to cause infection in the urinary tract. PMID:26930703

  1. Efficacy of a non-updated, Matrix-C-based equine influenza subunit-tetanus vaccine following Florida sublineage clade 2 challenge.

    PubMed

    Pouwels, H G W; Van de Zande, S M A; Horspool, L J I; Hoeijmakers, M J H

    2014-06-21

    Assessing the ability of current equine influenza vaccines to provide cross-protection against emerging strains is important. Horses not vaccinated previously and seronegative for equine influenza based on haemagglutination inhibition (HI) assay were assigned at random to vaccinated (n=7) or non-vaccinated (control, n=5) groups. Vaccination was performed twice four weeks apart with a 1 ml influenza subunit (A/eq/Prague/1/56, A/eq/Newmarket/1/93, A/eq/Newmarket/2/93), tetanus toxoid vaccine with Matrix-C adjuvant (EquilisPrequenza Te). All the horses were challenged individually by aerosol with A/eq/Richmond/1/07 three weeks after the second vaccination. Rectal temperature, clinical signs, serology and virus excretion were monitored for 14 days after challenge. There was no pain at the injection site or increases in rectal temperature following vaccination. Increases in rectal temperature and characteristic clinical signs were recorded in the control horses. Clinical signs were minimal in vaccinated horses. Clinical (P=0.0345) and total clinical scores (P=0.0180) were significantly lower in the vaccinated than in the control horses. Vaccination had a significant effect on indicators of viraemia - the extent (P=0.0006) and duration (P=<0.0001) of virus excretion and the total amount of virus excreted (AUC, P=0.0006). Vaccination also had a significant effect (P=0.0017) on whether a horse was positive or negative for virus excretion during the study. Further research is needed to fully understand the specific properties of this vaccine that may contribute to its cross-protective capacity.

  2. Matrix Extension Study: Validation of the Compact Dry EC Method for Enumeration of Escherichia coli and non-E. coli Coliform Bacteria in Selected Foods.

    PubMed

    Mizuochi, Shingo; Nelson, Maria; Baylis, Chris; Green, Becky; Jewell, Keith; Monadjemi, Farinaz; Chen, Yi; Salfinger, Yvonne; Fernandez, Maria Cristina

    2016-01-01

    The Compact Dry "Nissui" EC method, originally certified by the AOAC Research Institute Performance Test Method(SM) program for enumeration of Escherichia coli and non-E. coli coliforms in raw meat products (Performance Tested Method(SM) 110402), has undergone an evaluation to extend the method's claim to cooked chicken, prewashed bagged shredded iceberg lettuce, frozen cod filets, instant nonfat dry milk powder, and pasteurized milk (2% fat). Compact Dry EC is a ready-to-use dry media sheet containing a cold-soluble gelling agent, selective agents, and a chromogenic medium, which are rehydrated by adding 1 mL diluted sample. E. coli form blue/blue-purple colonies, whereas other coliform bacteria form red/pink colonies. Users can obtain an E. coli count (blue/blue-purple colonies only) and a total coliform count (red/pink plus blue/blue-purple colonies) after 24 ± 2 h of incubation at 37 ± 1°C. The matrix extension study was organized by Campden BRI (formerly Campden and Chorleywood Food Research Association Technology, Ltd), Chipping Campden, United Kingdom. Method comparison data for cooked chicken, prewashed bagged shredded iceberg lettuce, frozen cod filets, and instant nonfat dry milk powder were collected in a single-laboratory evaluation by Campden BRI. A multilaboratory study was conducted on pasteurized milk (2% fat), with 13 laboratories participating. The Compact Dry EC method was compared to ISO 16649-2:2001 "Microbiology of food and animal feeding stuffs-Horizontal method for the enumeration of beta-glucuronidase-positive Escherichia coli-Part 2: Colony-count technique at 44 degrees C using 5-bromo-4-chloro-3-indolyl beta-D-glucuronide" and to ISO 4832:2006 "Microbiology of food and animal feeding stuffs-Horizontal method for the enumeration of coliforms-Colony-count technique," the current standards at the time of this study. Each matrix was evaluated separately for E. coli and non-E. coli coliforms at each contamination level (including an

  3. Method for preparing porous metal hydride compacts

    DOEpatents

    Ron, Moshe; Gruen, Dieter M.; Mendelsohn, Marshall H.; Sheft, Irving

    1981-01-01

    A method for preparing porous metallic-matrix hydride compacts which can be repeatedly hydrided and dehydrided without disintegration. A mixture of a finely divided metal hydride and a finely divided matrix metal is contacted with a poison which prevents the metal hydride from dehydriding at room temperature and atmospheric pressure. The mixture of matrix metal and poisoned metal hydride is then compacted under pressure at room temperature to form porous metallic-matrix hydride compacts.

  4. Method for preparing porous metal hydride compacts

    DOEpatents

    Ron, M.; Gruen, D.M.; Mendelsohn, M.H.; Sheft, I.

    1980-01-21

    A method for preparing porous metallic-matrix hydride compacts which can be repeatedly hydrided and dehydrided without disintegration. A mixture of a finely divided metal hydride and a finely divided matrix metal is contacted with a poison which prevents the metal hydride from dehydriding at room temperature and atmospheric pressure. The mixture of matrix metal and poisoned metal hydride is then compacted under pressure at room temperature to form porous metallic-matrix hydride compacts.

  5. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry in the subunit stoichiometry study of high-mass non-covalent complexes

    NASA Astrophysics Data System (ADS)

    Moniatte, M.; Lesieur, C.; Vecsey-Semjen, B.; Buckley, J. T.; Pattus, F.; van der Goot, F. G.; van Dorsselaer, A.

    1997-12-01

    This study explores the potential of MALDI-TOF MS for the mass measurement of large non-covalent protein complexes. The following non-covalent complexes have been investigated: aerolysin from Aeromonas hydrophila (335 kDa) and [alpha]-haemolysin from Staphylococcus aureus (233 kDa) which are both cytolytic toxins, three enzymes known to be homotetramers in solution: bovine liver catalase (235 kDa), rabbit muscle pyruvate kinase (232 kDa), yeast alcohol dehydrogenase (147 kDa) and finally a lectin, concanavalin A (102 kDa). Three different matrix preparations were systematically tested under various conditions: ferulic acid dissolved in THF, 2,6-dihydroxyacetophenone in 20 mM aqueous ammonium citrate and a two-step sample preparation with sinapinic acid. It was possible to find a suitable combination of matrix and preparation type which allowed the molecularity of all complexes tested to be deduced from the MALDI mass spectrum. Trimeric and tetrameric intermediates accumulating during the formation of the active heptameric aerolysin complex were also identified, this allowing a formation mechanism to be proposed. The observation of large specific non-covalent complexes has been found to be dependent on the choice of matrix, the type of sample preparation used, the solvent evaporation speed, the pH of the resulting matrix-sample mixture and the number of shots acquired on a given area. From this set of experiments, some useful guidelines for the observation of large complexes by MALDI could therefore be deduced. Fast evaporation of the solvent is particularly necessary in the case of pH sensitive complexes. An ESMS study on the same non-covalent complexes indicated that, rather surprisingly, reliable results could be obtained by MALDI-TOF MS on several very large complexes (above 200 kDa) for which ESMS yielded no clear spectra.

  6. Adhesion of T and B lymphocytes to extracellular matrix and endothelial cells can be regulated through the beta subunit of VLA

    PubMed Central

    1992-01-01

    Investigating the regulation of very late antigen (VLA)-mediated functions, we found that TS2/16, a mAb directed against the beta chain of the VLA group of integrins, can induce binding of resting peripheral blood lymphocytes, cloned T lymphocytes, and Epstein Barr virus- transformed B cells to extracellular matrix components, fibronectin, laminin, and collagen, but not to fibrinogen. The antibody stimulates VLA-4-, VLA-5-, and VLA-6-mediated binding. Furthermore, it induces VLA- 4-mediated binding to vascular cell adhesion molecule-1 expressed by rTNF-alpha-stimulated endothelial cells, but it does not stimulate homotypic aggregation of cells as described for a number of anti-VLA-4 alpha antibodies (Bednarczyk, J.L., and B. W. McIntyre. 1990. J. Immunol. 144: 777-784; Campanero, M. R., R. Pulido, M. A. Ursa, M. Rodriguez-Moya, M. O. de Landazuri, and F. Sanchez-Madrid. 1990. J. Cell Biol. 110:2157-2165). Therefore, the stimulating activity of this anti-beta 1 antibody clearly contrasts with that of the anti-VLA-4 alpha antibodies, which induce homotypic cell aggregation, but not binding of cells to extracellular matrix components or endothelial cells, indicating that TS2/16 may generate different signals. The observation that also F(ab')2 or Fab fragments of this anti-beta 1 antibody stimulate binding to extracellular matrix components and endothelial cells excludes the possibility that binding requires receptor crosslinking, or is Fc receptor mediated. Induction of this adhesion is cation and energy dependent and requires an intact cytoskeleton. Although changes in the conformation of VLA integrins induced by this antibody may regulate their functional activity, the dependence on metabolic energy indicates that intracellular processes may also play a role. PMID:1560035

  7. Eudragit(®) RS PO/RL PO as rate-controlling matrix-formers via roller compaction: Influence of formulation and process variables on functional attributes of granules and tablets.

    PubMed

    Dave, Vivek S; Fahmy, Raafat M; Bensley, Dennis; Hoag, Stephen W

    2012-10-01

    The influence of plasticizer level, roll pressure and sintering temperature was investigated on the granule properties, tablet breaking force and theophylline release from tablets. Nine formulations using theophylline as a model drug, Eudragit(®) RL PO, Eudragit(®) RS PO, or both as a matrix former and triethyl citrate (TEC) as a plasticizer were prepared. The formulations were roller compacted and the granules obtained were evaluated for particle size distribution and flowability. These granules were compacted into tablets at a compression force of 7 kN. The tablets were thermally treated at different temperatures (50 and 75°C) for 5 h and were evaluated for breaking force and dissolution. Increase in roll pressure and TEC levels resulted in a progressive increase in the mean particle size of the granules. The flowability of the granules also improved with increasing roll pressures and TEC levels. Tablet breaking force increased with an increase in TEC levels and sintering temperatures. But these effects were significant only at the highest level of plasticizer and sintering temperature respectively. For the tablets containing Eudragit(®) RS PO, theophylline release decreased proportionately with increase in TEC levels and sintering temperatures. Tablets containing either Eudragit(®) RL PO or a mixture of RS PO and RL PO failed to impart an extended-release property to the tablets at the studied variables i.e. roll pressure, TEC levels and sintering temperature. It was clearly demonstrated that with suitable optimization of these parameters, the release-rate of a water soluble drug from the matrix tablets prepared via roller compaction can be finely controlled.

  8. VIBRATION COMPACTION

    DOEpatents

    Hauth, J.J.

    1962-07-01

    A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

  9. Evaluation of Matrix Tablets Based on Eudragit®E100/Carbopol®971P Combinations for Controlled Release and Improved Compaction Properties of Water Soluble Model Drug Paracetamol.

    PubMed

    Obeidat, Wasfy M; Nokhodchi, Ali; Alkhatib, Hatim

    2015-10-01

    The purpose of this work was to investigate the influence of Eudragit®E100 polymer in modifying the release rates and compaction properties of water soluble model drug paracetamol from Carbopol®971P NF polymer matrix tablets prepared by direct compression. The effects of the ratio of the two polymers, the total polymeric content, and the tablets mechanical strength on paracetamol release rates were investigated. Dissolution studies were conducted using USP XX Π rotating paddle apparatus at 50 rpm and 37°C at three different stages (pH 1.2, 4.8, and 6.8). Results showed that the polymers combination improved significantly the compaction properties of paracetamol tablets as evident by the higher crushing strengths (8.3 ± 0.4 Kp) compared to polymer-free tablets (3.4 ± 0.2 Kp) at intermediate compression pressure of 490 MPa. When combined with Carbopol®971P NF, Eudragit®E100 was found to be capable of extending paracetamol release for more than 12 h compared to 1 h for polymers-free tablets. The combined polymers were able to control paracetamol release in a pH independent pattern. The f2 (similarity factor) analysis showed that the ratio between the polymers and the total polymer concentration exhibited significant impact on drug release rates. In conclusion, Eudragit®E100 when combined with Carbopol®971P NF was capable of improving the compaction and sustained release properties of paracetamol. Korsmeyer-Peppas model was found to be the most suitable for fitting drug release data. The polymer combinations can potentially be used to control the release rates of highly water soluble drugs.

  10. Sodium channel auxiliary subunits.

    PubMed

    Tseng, Tsai-Tien; McMahon, Allison M; Johnson, Victoria T; Mangubat, Erwin Z; Zahm, Robert J; Pacold, Mary E; Jakobsson, Eric

    2007-01-01

    Voltage-gated ion channels are well known for their functional roles in excitable tissues. Excitable tissues rely on voltage-gated ion channels and their auxiliary subunits to achieve concerted electrical activity in living cells. Auxiliary subunits are also known to provide functional diversity towards the transport and biogenesis properties of the principal subunits. Recent interests in pharmacological properties of these auxiliary subunits have prompted significant amounts of efforts in understanding their physiological roles. Some auxiliary subunits can potentially serve as drug targets for novel analgesics. Three families of sodium channel auxiliary subunits are described here: beta1 and beta3, beta2 and beta4, and temperature-induced paralytic E (TipE). While sodium channel beta-subunits are encoded in many animal genomes, TipE has only been found exclusively in insects. In this review, we present phylogenetic analyses, discuss potential evolutionary origins and functional data available for each of these subunits. For each family, we also correlate the functional specificity with the history of evolution for the individual auxiliary subunits.

  11. Compact vortices

    NASA Astrophysics Data System (ADS)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.; Zafalan, I.

    2017-02-01

    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane.

  12. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  13. Compact magnetograph

    NASA Technical Reports Server (NTRS)

    Title, A. M.; Gillespie, B. A.; Mosher, J. W.

    1982-01-01

    A compact magnetograph system based on solid Fabry-Perot interferometers as the spectral isolation elements was studied. The theory of operation of several Fabry-Perot systems, the suitability of various magnetic lines, signal levels expected for different modes of operation, and the optimal detector systems were investigated. The requirements that the lack of a polarization modulator placed upon the electronic signal chain was emphasized. The PLZT modulator was chosen as a satisfactory component with both high reliability and elatively low voltage requirements. Thermal control, line centering and velocity offset problems were solved by a Fabry-Perot configuration.

  14. Technology Selections for Cylindrical Compact Fabrication

    SciTech Connect

    Jeffrey A. Phillips

    2010-10-01

    A variety of process approaches are available and have been used historically for manufacture of cylindrical fuel compacts. The jet milling, fluid bed overcoating, and hot press compacting approach being adopted in the U.S. AGR Fuel Development Program for scale-up of the compacting process involves significant paradigm shifts from historical approaches. New methods are being pursued because of distinct advantages in simplicity, yield, and elimination of process mixed waste. Recent advances in jet milling technology allow simplified dry matrix powder preparation. The matrix preparation method is well matched with patented fluid bed powder overcoating technology recently developed for the pharmaceutical industry and directly usable for high density fuel particle matrix overcoating. High density overcoating places fuel particles as close as possible to their final position in the compact and is matched with hot press compacting which fully fluidizes matrix resin to achieve die fill at low compacting pressures and without matrix end caps. Overall the revised methodology provides a simpler process that should provide very high yields, improve homogeneity, further reduce defect fractions, eliminate intermediate grading and QC steps, and allow further increases in fuel packing fractions.

  15. Diversity of insect nicotinic acetylcholine receptor subunits.

    PubMed

    Jones, Andrew K; Sattelle, David B

    2010-01-01

    Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that mediate fast synaptic transmission in the insect nervous system and are targets of a major group of insecticides, the neonicotinoids. They consist of five subunits arranged around a central ion channeL Since the subunit composition determines the functional and pharmacological properties of the receptor the presence of nAChR families comprising several subunit-encodinggenes provides a molecular basis for broad functional diversity. Analyses of genome sequences have shown that nAChR gene families remain compact in diverse insect species, when compared to their nematode andvertebrate counterparts. Thus, the fruit fly (Drosophila melanogaster), malaria mosquito (Anopheles gambiae), honey bee (Apis mellifera), silk worm (Bombyx mon) and the red flour beetle (Tribolium castaneum) possess 10-12 nAChR genes while human and the nematode Caenorhabditis elegans have 16 and 29 respectively. Although insect nAChRgene families are amongst the smallest known, receptor diversity can be considerably increased by the posttranscriptional processes alternative splicing and mRNA A-to-I editingwhich can potentially generate protein products which far outnumber the nAChR genes. These two processes can also generate species-specific subunit isoforms. In addition, each insect possesses at least one highly divergent nAChR subunit which may perform species-specific functions. Species-specific subunit diversification may offer promising targets for future rational design of insecticides that target specific pest insects while sparing beneficial species.

  16. Biofilm Matrix Proteins

    PubMed Central

    Fong, Jiunn N. C.; Yildiz, Fitnat H.

    2015-01-01

    Proteinaceous components of the biofilm matrix include secreted extracellular proteins, cell surface adhesins and protein subunits of cell appendages such as flagella and pili. Biofilm matrix proteins play diverse roles in biofilm formation and dissolution. They are involved in attaching cells to surfaces, stabilizing the biofilm matrix via interactions with exopolysaccharide and nucleic acid components, developing three-dimensional biofilm architectures, and dissolving biofilm matrix via enzymatic degradation of polysaccharides, proteins, and nucleic acids. In this chapter, we will review functions of matrix proteins in a selected set of microorganisms, studies of the matrix proteomes of Vibrio cholerae and Pseudomonas aeruginosa, and roles of outer membrane vesicles and of nucleoid-binding proteins in biofilm formation. PMID:26104709

  17. Compaction behavior of roller compacted ibuprofen.

    PubMed

    Patel, Sarsvatkumar; Kaushal, Aditya Mohan; Bansal, Arvind Kumar

    2008-06-01

    The effect of roller compaction pressure on the bulk compaction of roller compacted ibuprofen was investigated using instrumented rotary tablet press. Three different roller pressures were utilized to prepare granules and Heckel analysis, Walker analysis, compressibility, and tabletability were performed to derive densification, deformation, course of volume reduction and bonding phenomenon of different pressure roller compacted granules. Nominal single granule fracture strength was obtained by micro tensile testing. Heckel analysis indicated that granules prepared using lower pressure during roller compaction showed lower yield strength. The reduction in tabletability was observed for higher pressure roller compacted granules. The reduction in tabletability supports the results of granule size enlargement theory. Apart from the granule size enlargement theory, the available fines and relative fragmentation during compaction is responsible for higher bonding strength and provide larger areas for true particle contact at constant porosity for lower pressure roller compacted granules. Overall bulk compaction parameters indicated that granules prepared by lower roller compaction pressure were advantageous in terms of tabletability and densification. Overall results suggested that densification during roller compaction affects the particle level properties of specific surface area, nominal fracture strength, and compaction behavior.

  18. Compact Reactor

    SciTech Connect

    Williams, Pharis E.

    2007-01-30

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date.

  19. Recent Advances in Subunit Vaccine Carriers

    PubMed Central

    Vartak, Abhishek; Sucheck, Steven J.

    2016-01-01

    The lower immunogenicity of synthetic subunit antigens, compared to live attenuated vaccines, is being addressed with improved vaccine carriers. Recent reports indicate that the physio-chemical properties of these carriers can be altered to achieve optimal antigen presentation, endosomal escape, particle bio-distribution, and cellular trafficking. The carriers can be modified with various antigens and ligands for dendritic cells targeting. They can also be modified with adjuvants, either covalently or entrapped in the matrix, to improve cellular and humoral immune responses against the antigen. As a result, these multi-functional carrier systems are being explored for use in active immunotherapy against cancer and infectious diseases. Advancing technology, improved analytical methods, and use of computational methodology have also contributed to the development of subunit vaccine carriers. This review details recent breakthroughs in the design of nano-particulate vaccine carriers, including liposomes, polymeric nanoparticles, and inorganic nanoparticles. PMID:27104575

  20. Compact Process Development at Babcock & Wilcox

    SciTech Connect

    Eric Shaber; Jeffrey Phillips

    2012-03-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.

  1. Grassmann matrix quantum mechanics

    DOE PAGES

    Anninos, Dionysios; Denef, Frederik; Monten, Ruben

    2016-04-21

    We explore quantum mechanical theories whose fundamental degrees of freedom are rectangular matrices with Grassmann valued matrix elements. We study particular models where the low energy sector can be described in terms of a bosonic Hermitian matrix quantum mechanics. We describe the classical curved phase space that emerges in the low energy sector. The phase space lives on a compact Kähler manifold parameterized by a complex matrix, of the type discovered some time ago by Berezin. The emergence of a semiclassical bosonic matrix quantum mechanics at low energies requires that the original Grassmann matrices be in the long rectangular limit.more » In conclusion, we discuss possible holographic interpretations of such matrix models which, by construction, are endowed with a finite dimensional Hilbert space.« less

  2. Grassmann matrix quantum mechanics

    SciTech Connect

    Anninos, Dionysios; Denef, Frederik; Monten, Ruben

    2016-04-21

    We explore quantum mechanical theories whose fundamental degrees of freedom are rectangular matrices with Grassmann valued matrix elements. We study particular models where the low energy sector can be described in terms of a bosonic Hermitian matrix quantum mechanics. We describe the classical curved phase space that emerges in the low energy sector. The phase space lives on a compact Kähler manifold parameterized by a complex matrix, of the type discovered some time ago by Berezin. The emergence of a semiclassical bosonic matrix quantum mechanics at low energies requires that the original Grassmann matrices be in the long rectangular limit. In conclusion, we discuss possible holographic interpretations of such matrix models which, by construction, are endowed with a finite dimensional Hilbert space.

  3. The Compact for Education.

    ERIC Educational Resources Information Center

    Harrington, Fred Harvey

    The Compact for Education is not yet particularly significant either for good or evil. Partly because of time and partly because of unreasonable expectations, the Compact is not yet a going concern. Enthusiasts have overestimated Compact possibilities and opponents have overestimated its dangers, so if the organization has limited rather than…

  4. Petrochemical variation of Topopah Spring tuff matrix with depth (stratigraphic level), drill hole USW G-4, Yucca Mountain, Nevada

    SciTech Connect

    Byers, F.M. Jr.

    1985-12-01

    This study describes and interprets petrochemical variation of the matrix (excluding fractures and large gas cavities) of the Topopah Spring Member of the Paintbrush Tuff. This tuff includes the candidate host rock for a high-level nuclear waste repository at Yucca Mountain on the Nevada Test Site. Cored hole USW G-4, near the site of a potential exploratory shaft at Yucca Mountain, penetrated 359.4 m (1179 ft) of the member within the unsaturated zone. This study shows that petrographic textures and chemistry of the matrix vary systematically within recognizable lithologic subunits related to crystallization (cooling) zones, welding (compaction) zones, and compositional zones (rhyolite versus quartz latite). The methods used for this study include petrographic modal thin section analysis using an automated counter and electron microprobe analysis of the groundmass. Distinctive textural categories are defined, and they can be ranked from finest to coarsest as vitrophyre (glass), cryptocrystalline groundmass, spherulites, granophyre, lithic fragments, and phenocrysts. The two main groundmass compositions are also defined: rhyolite high silica) and quartz latite. The value of these petrochemical studies lies in providing microscopic criteria for recognizing the zonal subunits where they may have greatly limited exposure, as in mined drifts and in core from horizontal drill holes. For example, the lower nonlithophysal zone can be distinguished microscopically from the middle nonlithophysal zone by (1) degree of compaction, (2) amount of quartz, and (3) amount of lithic fragments. The variability between these textural categories should also be considered in designing physical and chemical tests of the Topopah Spring.

  5. Highly conserved small subunit residues influence rubisco large subunit catalysis.

    PubMed

    Genkov, Todor; Spreitzer, Robert J

    2009-10-30

    The chloroplast enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step of photosynthetic CO(2) fixation. With a deeper understanding of its structure-function relationships and competitive inhibition by O(2), it may be possible to engineer an increase in agricultural productivity and renewable energy. The chloroplast-encoded large subunits form the active site, but the nuclear-encoded small subunits can also influence catalytic efficiency and CO(2)/O(2) specificity. To further define the role of the small subunit in Rubisco function, the 10 most conserved residues in all small subunits were substituted with alanine by transformation of a Chlamydomonas reinhardtii mutant that lacks the small subunit gene family. All the mutant strains were able to grow photosynthetically, indicating that none of the residues is essential for function. Three of the substitutions have little or no effect (S16A, P19A, and E92A), one primarily affects holoenzyme stability (L18A), and the remainder affect catalysis with or without some level of associated structural instability (Y32A, E43A, W73A, L78A, P79A, and F81A). Y32A and E43A cause decreases in CO(2)/O(2) specificity. Based on the x-ray crystal structure of Chlamydomonas Rubisco, all but one (Glu-92) of the conserved residues are in contact with large subunits and cluster near the amino- or carboxyl-terminal ends of large subunit alpha-helix 8, which is a structural element of the alpha/beta-barrel active site. Small subunit residues Glu-43 and Trp-73 identify a possible structural connection between active site alpha-helix 8 and the highly variable small subunit loop between beta-strands A and B, which can also influence Rubisco CO(2)/O(2) specificity.

  6. Advancements in the development of subunit influenza vaccines

    PubMed Central

    Zhang, Naru; Zheng, Bo-Jian; Lu, Lu; Zhou, Yusen; Jiang, Shibo; Du, Lanying

    2014-01-01

    The ongoing threat of influenza epidemics and pandemics has emphasized the importance of developing safe and effective vaccines against infections from divergent influenza viruses. In this review, we first introduce the structure and life cycle of influenza A viruses, describing major influenza A virus-caused pandemics. We then compare different types of influenza vaccines and discuss current advancements in the development of subunit influenza vaccines, particularly those based on nucleoprotein (NP), extracellular domain of matrix protein 2 (M2e) and hemagglutinin (HA) proteins. We also illustrate potential strategies for improving the efficacy of subunit influenza vaccines. PMID:25529753

  7. Dynamical compactness and sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Wen; Khilko, Danylo; Kolyada, Sergiĭ; Zhang, Guohua

    2016-05-01

    To link the Auslander point dynamics property with topological transitivity, in this paper we introduce dynamically compact systems as a new concept of a chaotic dynamical system (X , T) given by a compact metric space X and a continuous surjective self-map T : X → X. Observe that each weakly mixing system is transitive compact, and we show that any transitive compact M-system is weakly mixing. Then we discuss the relationships between it and other several stronger forms of sensitivity. We prove that any transitive compact system is Li-Yorke sensitive and furthermore multi-sensitive if it is not proximal, and that any multi-sensitive system has positive topological sequence entropy. Moreover, we show that multi-sensitivity is equivalent to both thick sensitivity and thickly syndetic sensitivity for M-systems. We also give a quantitative analysis for multi-sensitivity of a dynamical system.

  8. Stabilization of compactible waste

    SciTech Connect

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs.

  9. Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant

    SciTech Connect

    Jeffrey J. Einerson; Jeffrey A. Phillips; Eric L. Shaber; Scott E. Niedzialek; W. Clay Richardson; Scott G. Nagley

    2012-10-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

  10. Modelling dynamic compaction of porous materials with the overstress approach

    NASA Astrophysics Data System (ADS)

    Partom, Y.

    2014-05-01

    To model compaction of a porous material we need 1) an equation of state of the porous material in terms of the equation of state of its matrix, and 2) a compaction law. For an equation of state it is common to use Herrmann's suggestion, as in his Pα model. For a compaction law it is common to use a quasi-static compaction relation obtained from 1) a meso-scale model (as in Carroll and Holt's spherical shell model), or from 2) quasi-static tests. Here we are interested in dynamic compaction, like in a planar impact test. In dynamic compaction the state may change too fast for the state point to follow the quasi-static compaction curve. We therefore get an overstress situation. The state point moves out of the quasi-static compaction boundary, and only with time collapses back towards it at a certain rate. In this way the dynamic compaction event becomes rate dependent. In the paper we first write down the rate equations for dynamic compaction according to the overstress approach. We then implement these equations in a hydro-code and run some examples. We show how the overstress rate parameter can be calibrated from tests.

  11. Modeling Dynamic Compaction of Porous Materials with the Overstress Approach

    NASA Astrophysics Data System (ADS)

    Partom, Yehuda

    2013-06-01

    To model compaction of a porous material (PM) we need 1) an equation of state (EOS) of the PM in terms of the EOS of its matrix, and 2) a compaction law. For the EOS it is common to use Herrmann's suggestion, as in his P α model. For a compaction law it is common to use a quasi-static compaction relation obtained from 1) a mezzo-scale model (as in Carroll and Holt's spherical shell model), or from 2) quasi-static tests. Here we are interested in dynamic compaction, like in a planar impact test. In dynamic compaction, the state may change too fast for the state point to follow the quasi-static compaction curve. We therefore get an overstress situation. The state point moves out of the quasi-static compaction boundary, and only with time collapses back towards it at a certain rate. In this way the dynamic compaction event becomes rate dependent. In the paper we first write down the rate equations for dynamic compaction according to this overstress approach. We then implement these equations in a hydro-code, and run some examples. We show how the overstress rate parameter can be calibrated from tests.

  12. Compact microchannel system

    DOEpatents

    Griffiths, Stewart

    2003-09-30

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  13. Single-particle tracking reveals that free ribosomal subunits are not excluded from the Escherichia coli nucleoid.

    PubMed

    Sanamrad, Arash; Persson, Fredrik; Lundius, Ebba G; Fange, David; Gynnå, Arvid H; Elf, Johan

    2014-08-05

    Biochemical and genetic data show that ribosomes closely follow RNA polymerases that are transcribing protein-coding genes in bacteria. At the same time, electron and fluorescence microscopy have revealed that ribosomes are excluded from the Escherichia coli nucleoid, which seems to be inconsistent with fast translation initiation on nascent mRNA transcripts. The apparent paradox can be reconciled if translation of nascent mRNAs can start throughout the nucleoid before they relocate to the periphery. However, this mechanism requires that free ribosomal subunits are not excluded from the nucleoid. Here, we use single-particle tracking in living E. coli cells to determine the fractions of free ribosomal subunits, classify individual subunits as free or mRNA-bound, and quantify the degree of exclusion of bound and free subunits separately. We show that free subunits are not excluded from the nucleoid. This finding strongly suggests that translation of nascent mRNAs can start throughout the nucleoid, which reconciles the spatial separation of DNA and ribosomes with cotranscriptional translation. We also show that, after translation inhibition, free subunit precursors are partially excluded from the compacted nucleoid. This finding indicates that it is active translation that normally allows ribosomal subunits to assemble on nascent mRNAs throughout the nucleoid and that the effects of translation inhibitors are enhanced by the limited access of ribosomal subunits to nascent mRNAs in the compacted nucleoid.

  14. Physically detached 'compact groups'

    NASA Technical Reports Server (NTRS)

    Hernquist, Lars; Katz, Neal; Weinberg, David H.

    1995-01-01

    A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable disagreement among researchers attempting to deduce the dynamical state of these systems. In this paper, we suggest that many of the observed groups are not physically bound but are chance projections of galaxies well separated along the line of sight. Unlike earlier similar proposals, ours does not require that the galaxies in the compact group be members of a more diffuse, but physically bound entity. The probability of physically separated galaxies projecting into an apparent compact group is nonnegligible if most galaxies are distributed in thin filaments. We illustrate this general point with a specific example: a simulation of a cold dark matter universe, in which hydrodynamic effects are included to identify galaxies. The simulated galaxy distribution is filamentary and end-on views of these filaments produce apparent galaxy associations that have sizes and velocity dispersions similar to those of observed compact groups. The frequency of such projections is sufficient, in principle, to explain the observed space density of groups in the Hickson catalog. We discuss the implications of our proposal for the formation and evolution of groups and elliptical galaxies. The proposal can be tested by using redshift-independent distance estimators to measure the line-of-sight spatial extent of nearby compact groups.

  15. The ribosomal subunit assembly line

    PubMed Central

    Dlakić, Mensur

    2005-01-01

    Recent proteomic studies in Saccharomyces cerevisiae have identified nearly 200 proteins, other than the structural ribosomal proteins, that participate in the assembly of ribosomal subunits and their transport from the nucleus. In a separate line of research, proteomic studies of mature plant ribosomes have revealed considerable variability in the protein composition of individual ribosomes. PMID:16207363

  16. Rotating proton pumping ATPases: subunit/subunit interactions and thermodynamics.

    PubMed

    Nakanishi-Matsui, Mayumi; Sekiya, Mizuki; Futai, Masamitsu

    2013-03-01

    In this article, we discuss single molecule observation of rotational catalysis by E. coli ATP synthase (F-ATPase) using small gold beads. Studies involving a low viscous drag probe showed the stochastic properties of the enzyme in alternating catalytically active and inhibited states. The importance of subunit interaction between the rotor and the stator, and thermodynamics of the catalysis are also discussed. "Single Molecule Enzymology" is a new trend for understanding enzyme mechanisms in biochemistry and physiology.

  17. Preliminary results of post-irradiation examination of the AGR-1 TRISO fuel compacts

    SciTech Connect

    Paul Demkowicz; John Hunn; Robert Morris; Jason Harp; Philip Winston; Charles Baldwin; Fred Montgomery; Scott Ploger; Isabella van Rooyen

    2012-10-01

    Five irradiated fuel compacts from the AGR-1 experiment have been examined in detail in order to assess in-pile fission product release behavior. Compacts were electrolytically deconsolidated and analyzed using the leach-burn-leach technique to measure fission product inventory in the compact matrix and identify any particles with a defective SiC layer. Loose particles were then gamma counted to measure the fission product inventory. One particle with a defective SiC layer was found in the five compacts examined. The fractional release of Ag 110m from the particles was significant. The total fraction of silver released from all the particles within a compact ranged from 0-0.63 and individual particles within a single compact often exhibited a very wide range of silver release. The average fractional release of Eu-154 from all particles in a compact was 2.4×10-4—1.3×10-2, which is indicative of release through intact coatings. The fractional Cs-134 inventory in the compact matrix was <2×10-5 when all coatings remained intact, indicating good cesium retention. Approximately 1% of the palladium inventory was found in the compact matrix for two of the compacts, indicating significant release through intact coatings.

  18. Ribosomal small subunit domains radiate from a central core

    PubMed Central

    Gulen, Burak; Petrov, Anton S.; Okafor, C. Denise; Vander Wood, Drew; O’Neill, Eric B.; Hud, Nicholas V.; Williams, Loren Dean

    2016-01-01

    The domain architecture of a large RNA can help explain and/or predict folding, function, biogenesis and evolution. We offer a formal and general definition of an RNA domain and use that definition to experimentally characterize the rRNA of the ribosomal small subunit. Here the rRNA comprising a domain is compact, with a self-contained system of molecular interactions. A given rRNA helix or stem-loop must be allocated uniquely to a single domain. Local changes such as mutations can give domain-wide effects. Helices within a domain have interdependent orientations, stabilities and interactions. With these criteria we identify a core domain (domain A) of small subunit rRNA. Domain A acts as a hub, linking the four peripheral domains and imposing orientational and positional restraints on the other domains. Experimental characterization of isolated domain A, and mutations and truncations of it, by methods including selective 2′OH acylation analyzed by primer extension and circular dichroism spectroscopy are consistent with our architectural model. The results support the utility of the concept of an RNA domain. Domain A, which exhibits structural similarity to tRNA, appears to be an essential core of the small ribosomal subunit. PMID:26876483

  19. All three subunits of soybean beta-conglycinin are potential food allergens.

    PubMed

    Krishnan, Hari B; Kim, Won-Seok; Jang, Sungchan; Kerley, Monty S

    2009-02-11

    Soybeans are recognized as one of the "big 8" food allergens. IgE antibodies from soybean-sensitive patients recognize more than 15 soybean proteins. Among these proteins only the alpha-subunit of beta-conglycinin, but not the highly homologous alpha'- and beta-subunits, has been shown to be a major allergenic protein. The objective of this study was to examine if the alpha'- and beta-subunits of beta-conglycinin can also serve as potential allergens. Immunoblot analysis using sera collected from soybean-allergic patients revealed the presence of IgE antibodies that recognized several soy proteins including 72, 70, 52, 34, and 21 kDa proteins. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) analysis of trypsin-digested 72, 70, and 52 kDa proteins indicated that these proteins were the alpha'-, alpha-, and beta-subunits of beta-conglycinin, respectively. Additionally, purified alpha'-, alpha-, and beta-subunits of beta-conglycinin were recognized by IgE antibodies present in the soybean-allergic patients. The IgE reactivity to the beta-subunit of beta-conglycinin was not abolished when this glycoprotein was either deglycosylated using glycosidases or expressed as a recombinant protein in Escherichia coli . The results suggest that in addition to the previously recognized alpha-subunit of beta-conglycinin, the alpha'- and beta-subunits of beta-conglycinin also are potential food allergens.

  20. Compact optical transconductance varistor

    SciTech Connect

    Sampayan, Stephen

    2015-09-22

    A compact radiation-modulated transconductance varistor device having both a radiation source and a photoconductive wide bandgap semiconductor material (PWBSM) integrally formed on a substrate so that a single interface is formed between the radiation source and PWBSM for transmitting PWBSM activation radiation directly from the radiation source to the PWBSM.

  1. Compact rotating cup anemometer

    NASA Technical Reports Server (NTRS)

    Wellman, J. B.

    1968-01-01

    Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

  2. Compact, Integrated Photoelectron Linacs

    NASA Astrophysics Data System (ADS)

    Yu, David

    2000-12-01

    The innovative compact high energy iniector which has been developed by DULY Research Inc., will have wide scientific industrial and medical applications. The new photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injector and the linac. By focusing the beam with solenoid or permanent magnets, and producing high current with low emittance, extremely high brightness is achieved. In addition to providing a small footprint and improved beam quality in an integrated structure, the compact system considerably simplifies external subsystems required to operate the photoelectron linac, including rf power transport, beam focusing, vacuum and cooling. The photoelectron linac employs an innovative Plane-Wave-Transformer (PWT) design, which provides strong cell-to-cell coupling, relaxes manufacturing tolerance and facilitates the attachment of external ports to the compact structure with minimal field interference. DULY Research Inc. under the support of the DOE Small Business Innovation Research (SBIR) program, has developed, constructed and installed a 20-MeV, S-band compact electron source at UCLA. DULY Research is also presently engaged in the development of an X-band photoelectron linear accelerator in another SBIR project. The higher frequency structure when completed will be approximately three times smaller, and capable of a beam brightness ten times higher than the S-band structure.

  3. Compact Solar Camera.

    ERIC Educational Resources Information Center

    Juergens, Albert

    1980-01-01

    Describes a compact solar camera built as a one-semester student project. This camera is used for taking pictures of the sun and moon and for direct observation of the image of the sun on a screen. (Author/HM)

  4. COMPACT SCHOOL AND $$ SAVINGS.

    ERIC Educational Resources Information Center

    BAIR, W.G.

    A REVIEW OF THE CRITERIA FOR CONSIDERING THE USE OF A TOTAL ENERGY SYSTEM WITHIN A SCHOOL BUILDING STATES THE WINDOWLESS, COMPACT SCHOOL OFFERS MORE EFFICIENT SPACE UTILIZATION WITH LESS AREA REQUIRED FOR GIVEN STUDENT POPULATION AND LOWER OPERATION COSTS. THE AUTHOR RECOMMENDS THAT THESE BUILDINGS BE WINDOWLESS TO REDUCE HEAT COSTS, HOWEVER, AT…

  5. Limestone compaction: an enigma

    USGS Publications Warehouse

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  6. Compact Information Representations

    DTIC Science & Technology

    2016-08-02

    proposal aims at developing mathematically rigorous and general- purpose statistical methods based on stable random projections, to achieve compact...faced with very large, inherently high-dimensional, or naturally streaming datasets. This pro- posal aims at developing mathematically rigorous and

  7. Experimental Measurement and Numerical Modeling of the Effective Thermal Conductivity of TRISO Fuel Compacts

    SciTech Connect

    Folsom, Charles; Xing, Changhu; Jensen, Colby; Ban, Heng; Marshall, Douglas W.

    2015-03-01

    Accurate modeling capability of thermal conductivity of tristructural-isotropic (TRISO) fuel compacts is important to fuel performance modeling and safety of Generation IV reactors. To date, the effective thermal conductivity (ETC) of tristructural-isotropic (TRISO) fuel compacts has not been measured directly. The composite fuel is a complicated structure comprised of layered particles in a graphite matrix. In this work, finite element modeling is used to validate an analytic ETC model for application to the composite fuel material for particle-volume fractions up to 40%. The effect of each individual layer of a TRISO particle is analyzed showing that the overall ETC of the compact is most sensitive to the outer layer constituent. In conjunction with the modeling results, the thermal conductivity of matrix-graphite compacts and the ETC of surrogate TRISO fuel compacts have been successfully measured using a previously developed measurement system. The ETC of the surrogate fuel compacts varies between 50 and 30 W m-1 K-1 over a temperature range of 50-600°C. As a result of the numerical modeling and experimental measurements of the fuel compacts, a new model and approach for analyzing the effect of compact constituent materials on ETC is proposed that can estimate the fuel compact ETC with approximately 15-20% more accuracy than the old method. Using the ETC model with measured thermal conductivity of the graphite matrix-only material indicate that, in the composite form, the matrix material has a much greater thermal conductivity, which is attributed to the high anisotropy of graphite thermal conductivity. Therefore, simpler measurements of individual TRISO compact constituents combined with an analytic ETC model, will not provide accurate predictions of overall ETC of the compacts emphasizing the need for measurements of composite, surrogate compacts.

  8. Compact Spreader Schemes

    SciTech Connect

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  9. Compact spreader schemes

    NASA Astrophysics Data System (ADS)

    Placidi, M.; Jung, J.-Y.; Ratti, A.; Sun, C.

    2014-12-01

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  10. Compact optical isolator.

    PubMed

    Sansalone, F J

    1971-10-01

    This paper describes a compact Faraday rotation isolator using terbium aluminum garnet (TAG) as the Faraday rotation material and small high field permanent magnets made of copper-rare earth alloys. The nominal isolation is 26 dB with a 0.4-dB forward loss. The present isolator can be adjusted to provide effective isolation from 4880 A to 5145 A. Details of the design, fabrication, and performance of the isolator are presented.

  11. Compact Torsatron configurations

    SciTech Connect

    Carreras, B. A.; Dominguez, N.; Garcia, L.; Lynch, V. E.; Lyon, J. F.; Cary, J. R.; Hanson, J. D.; Navarro, A. P.

    1987-09-01

    Low-aspect-ratio stellarator configurations can be realized by using torsatron winding. Plasmas with aspect ratios in the range of 3.5 to 5 can be confined by these Compact Torsatron configurations. Stable operation at high BETA should be possible in these devices, if a vertical field coil system is adequately designed to avoid breaking of the magnetic surfaces at finite BETA. 17 refs., 21 figs., 1 tab.

  12. Compact power reactor

    DOEpatents

    Wetch, Joseph R.; Dieckamp, Herman M.; Wilson, Lewis A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

  13. Hydraulic conductivity of compacted zeolites.

    PubMed

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  14. Compact gate valve

    DOEpatents

    Bobo, Gerald E.

    1977-01-01

    This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

  15. COMPACT CASCADE IMPACTS

    DOEpatents

    Lippmann, M.

    1964-04-01

    A cascade particle impactor capable of collecting particles and distributing them according to size is described. In addition the device is capable of collecting on a pair of slides a series of different samples so that less time is required for the changing of slides. Other features of the device are its compactness and its ruggedness making it useful under field conditions. Essentially the unit consists of a main body with a series of transverse jets discharging on a pair of parallel, spaced glass plates. The plates are capable of being moved incremental in steps to obtain the multiple samples. (AEC)

  16. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  17. Oil shale compaction experimental results

    SciTech Connect

    Fahy, L.J.

    1985-11-01

    Oil shale compaction reduces the void volume available for gas flow in vertical modified in situ (VMIS) retorts. The mechanical forces caused by the weight of the overlying shale can equal 700 kPa near the bottom of commercial retorts. Clear evidence of shale compaction was revealed during postburn investigation of the Rio Blanco retorts at the C-a lease tract in Colorado. Western Research Institute conducted nine laboratory experiments to measure the compaction of Green River oil shale rubble during retorting. The objectives of these experiments were (1) to determine the effects of particle size, (2) to measure the compaction of different shale grades with 12 to 25 percent void volume and (3) to study the effects of heating rate on compaction. The compaction recorded in these experiments can be separated into the compaction that occurred during retorting and the compaction that occurred as the retort cooled down. The leaner oil shale charges compacted about 3 to 4 percent of the bed height at the end of retorting regardless of the void volume or heating rate. The richer shale charges compacted by 6.6 to 22.9 percent of the bed height depending on the shale grade and void volume used. Additional compaction of approximately 1.5 to 4.3 percent of the bed height was measured as the oil shale charges cooled down. Compaction increased with an increase in void volume for oil shale grades greater than 125 l/Mg. The particle size of the oil shale brick and the heating rate did not have a significant effect on the amount of compaction measured. Kerogen decomposition is a major factor in the compaction process. The compaction may be influenced by the bitumen intermediate acting as a lubricant, causing compaction to occur over a narrow temperature range between 315 and 430/sup 0/C. While the majority of the compaction occurs early in the retorting phase, mineral carbonate decomposition may also increase the amount of compaction. 14 refs., 12 figs., 4 tabs.

  18. The Subunit Structure of Benzylsuccinate Synthase†

    PubMed Central

    Li, Lei; Patterson, Dustin P.; Fox, Christel C.; Lin, Brian; Coschigano, Peter W.; Marsh, E. Neil G.

    2010-01-01

    Benzylsuccinate synthase is a member of the glycyl radical family of enzymes. It catalyzes the addition of toluene to fumarate to form benzylsuccinate as the first step in the anaerobic pathway of toluene fermentation. The enzyme comprises three subunits α, β and γ that in Thauera Aromatica T1 strain are encoded by the tutD, tutG and tutF genes respectively. The large α-subunit contains the essential glycine and cysteine residues that are conserved in all glycyl radical enzymes. However, the function of the small β- and γ-subunits has remained unclear. We have over-expressed all three subunits of benzylsuccinate synthase in E. coli, both individually and in combination. Co-expression of the γ-subunit (but not the β-subunit) is essential for efficient expression of the α-subunit. The benzylsuccinate synthase complex lacking the glycyl radical could be purified as an α2β2γ2 hexamer by nickel-affinity chromatography through a ‘His6’ affinity tag engineered onto the C-terminus of the α-subunit. Unexpectedly, BSS was found to contain two iron-sulfur clusters, one associated with the β-subunit and the other with the γ-subunit that appear to be necessary for the structural integrity of the complex. The spectroscopic properties of these clusters suggest that they are most likely [4Fe-4S] clusters. Removal of iron with chelating agents results in dissociation of the complex; similarly a mutant γ-subunit lacking the [4Fe-4S] cluster is unable to stabilize the α-subunit when the proteins are co-expressed. PMID:19159265

  19. Scalable Nonlinear Compact Schemes

    SciTech Connect

    Ghosh, Debojyoti; Constantinescu, Emil M.; Brown, Jed

    2014-04-01

    In this work, we focus on compact schemes resulting in tridiagonal systems of equations, specifically the fifth-order CRWENO scheme. We propose a scalable implementation of the nonlinear compact schemes by implementing a parallel tridiagonal solver based on the partitioning/substructuring approach. We use an iterative solver for the reduced system of equations; however, we solve this system to machine zero accuracy to ensure that no parallelization errors are introduced. It is possible to achieve machine-zero convergence with few iterations because of the diagonal dominance of the system. The number of iterations is specified a priori instead of a norm-based exit criterion, and collective communications are avoided. The overall algorithm thus involves only point-to-point communication between neighboring processors. Our implementation of the tridiagonal solver differs from and avoids the drawbacks of past efforts in the following ways: it introduces no parallelization-related approximations (multiprocessor solutions are exactly identical to uniprocessor ones), it involves minimal communication, the mathematical complexity is similar to that of the Thomas algorithm on a single processor, and it does not require any communication and computation scheduling.

  20. Compaction of Titanium Powders

    SciTech Connect

    Gerdemann, Stephen,J; Jablonski, Paul, J

    2011-05-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  1. Compact electrostatic comb actuator

    DOEpatents

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  2. Compaction of Titanium Powders

    SciTech Connect

    Stephen J. Gerdemann; Paul D. Jablonski

    2010-11-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 μm, <75 μm, and < 45 μm; two different sizes of a hydride-dehydride [HDH] <75 μm and < 45 μm; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  3. Compact Infrasonic Windscreen

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J.; Shams, Qamar A.; Sealey, Bradley S.; Comeaux, Toby

    2005-01-01

    A compact windscreen has been conceived for a microphone of a type used outdoors to detect atmospheric infrasound from a variety of natural and manmade sources. Wind at the microphone site contaminates received infrasonic signals (defined here as sounds having frequencies <20 Hz), because a microphone cannot distinguish between infrasonic pressures (which propagate at the speed of sound) and convective pressure fluctuations generated by wind turbulence. Hence, success in measurement of outdoor infrasound depends on effective screening of the microphone from the wind. The present compact windscreen is based on a principle: that infrasound at sufficiently large wavelength can penetrate any barrier of practical thickness. Thus, a windscreen having solid, non-porous walls can block convected pressure fluctuations from the wind while transmitting infrasonic acoustic waves. The transmission coefficient depends strongly upon the ratio between the acoustic impedance of the windscreen and that of air. Several materials have been found to have impedance ratios that render them suitable for use in constructing walls that have practical thicknesses and are capable of high transmission of infrasound. These materials (with their impedance ratios in parentheses) are polyurethane foam (222), space shuttle tile material (332), balsa (323), cedar (3,151), and pine (4,713).

  4. Role of the Rubisco Small Subunit

    SciTech Connect

    Spreitzer, Robert Joseph

    2016-11-05

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step of CO2 fixation in photosynthesis. However, it is a slow enzyme, and O2 competes with CO2 at the active site. Oxygenation initiates the photorespiratory pathway, which also results in the loss of CO2. If carboxylation could be increased or oxygenation decreased, an increase in net CO2 fixation would be realized. Because Rubisco provides the primary means by which carbon enters all life on earth, there is much interest in engineering Rubisco to increase the production of food and renewable energy. Rubisco is located in the chloroplasts of plants, and it is comprised of two subunits. Much is known about the chloroplast-gene-encoded large subunit (rbcL gene), which contains the active site, but much less is known about the role of the nuclear-gene-encoded small subunit in Rubisco function (rbcS gene). Both subunits are coded by multiple genes in plants, which makes genetic engineering difficult. In the eukaryotic, green alga Chlamydomonas reinhardtii, it has been possible to eliminate all the Rubisco genes. These Rubisco-less mutants can be maintained by providing acetate as an alternative carbon source. In this project, focus has been placed on determining whether the small subunit might be a better genetic-engineering target for improving Rubisco. Analysis of a variable-loop structure (βA-βB loop) of the small subunit by genetic selection, directed mutagenesis, and construction of chimeras has shown that the small subunit can influence CO2/O2 specificity. X-ray crystal structures of engineered chimeric-loop enzymes have indicated that additional residues and regions of the small subunit may also contribute to Rubisco function. Structural dynamics of the small-subunit carboxyl terminus was also investigated. Alanine-scanning mutagenesis of the most-conserved small-subunit residues has identified a

  5. Matrix thermalization

    NASA Astrophysics Data System (ADS)

    Craps, Ben; Evnin, Oleg; Nguyen, Kévin

    2017-02-01

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  6. METHOD OF FORMING ELONGATED COMPACTS

    DOEpatents

    Larson, H.F.

    1959-05-01

    A powder compacting procedure and apparatus which produces elongated compacts of Be is described. The powdered metal is placed in a thin metal tube which is chemically compatible to lubricant, powder, atmosphere, and die material and will undergo a high degree of plastic deformation and have intermediate hardness. The tube is capped and placed in the die, and punches are applied to the ends. During the compacting stroke the powder seizes the tube and a thickening and shortening of the tube occurs. The tube is easily removed from the die, split, and peeled from the compact. (T.R.H.)

  7. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  8. Multipurpose Compact Spectrometric Unit

    SciTech Connect

    Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan

    2009-11-09

    A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

  9. Compact photonic spin filters

    NASA Astrophysics Data System (ADS)

    Ke, Yougang; Liu, Zhenxing; Liu, Yachao; Zhou, Junxiao; Shu, Weixing; Luo, Hailu; Wen, Shuangchun

    2016-10-01

    In this letter, we propose and experimentally demonstrate a compact photonic spin filter formed by integrating a Pancharatnam-Berry phase lens (focal length of ±f ) into a conventional plano-concave lens (focal length of -f). By choosing the input port of the filter, photons with a desired spin state, such as the right-handed component or the left-handed one, propagate alone its original propagation direction, while the unwanted spin component is quickly diverged after passing through the filter. One application of the filter, sorting the spin-dependent components of vector vortex beams on higher-order Poincaré sphere, is also demonstrated. Our scheme provides a simple method to manipulate light, and thereby enables potential applications for photonic devices.

  10. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  11. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  12. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  13. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  14. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  15. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  16. Compact artificial hand

    NASA Technical Reports Server (NTRS)

    Wiker, G. A.; Mann, W. A. (Inventor)

    1979-01-01

    A relatively simple, compact artificial hand, is described which includes hooks pivotally mounted on first frame to move together and apart. The first frame is rotatably mounted on a second frame to enable "turning at the wrist" movement without limitation. The second frame is pivotally mounted on a third frame to permit 'flexing at the wrist' movement. A hook-driving motor is fixed to the second frame but has a shaft that drives a speed reducer on the first frame which, in turn, drives the hooks. A second motor mounted on the second frame, turns a gear on the first frame to rotate the first frame and the hooks thereon. A third motor mounted on the third frame, turns a gear on a second frame to pivot it.

  17. 28 CFR 51.6 - Political subunits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Political subunits. 51.6 Section 51.6 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF SECTION 5 OF THE VOTING RIGHTS ACT OF 1965, AS AMENDED General Provisions § 51.6 Political subunits. All...

  18. Sync Matrix

    SciTech Connect

    Metz, William C.; Metz, W. Chris; Mitrani, Jacques E.; Hewett, Jr., Paul L.; Jones, Christopher A.

    2004-12-31

    Sync Matrix provides a graphic display of the relationships among all of the response activities of each jurisdiction. This is accomplished through software that organizes and displays the activities by jurisdiction, function, and time for easy review and analysis. The software can also integrate the displays of multiple jurisdictions to allow examination of the total response.

  19. Hand-Held Ultrasonic Instrument for Reading Matrix Symbols

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kula, John P.; Gurney, John W.; Lior, Ephraim D.

    2008-01-01

    A hand-held instrument that would include an ultrasonic camera has been proposed as an efficient means of reading matrix symbols. The proposed instrument could be operated without mechanical raster scanning. All electronic functions from excitation of ultrasonic pulses through final digital processing for decoding matrix symbols would be performed by dedicated circuitry within the single, compact instrument housing.

  20. Ricin and Ricinus communis agglutinin subunits are all derived from a single-size polypeptide precursor.

    PubMed

    Butterworth, A G; Lord, J M

    1983-12-01

    Antibodies have been raised in rabbits against the individually purified A and B subunits of the toxic castor bean lectin, ricin, and against the A' and B' subunits of Ricinus communis agglutinin type I. Each of the antisera recognised a single polypeptide species of Mr 60 500 when maturing castor bean endosperm mRNA was translated in vitro in a rabbit-reticulocyte-derived system. When dog pancreatic microsomal vesicles were included in the translational system, each subunit antiserum precipitated a group of 66 000-68 000-Mr core-glycosylated polypeptides which had been translocated into the lumen of the vesicles. The 60 500-Mr polypeptide appeared to be a common precursor to all four individual lectin subunits since (a) its glycosylated (66 000-68 000-Mr) forms were readily detected in the endoplasmic reticulum fraction isolated from maturing castor bean endosperm and (b) pulse-chase studies showed that the glycosylated precursors disappeared from the endoplasmic reticulum fraction with the concomittant appearance of authentic lectin subunits in a soluble protein fraction which included protein body matrix components. Antiserum prepared against whole R. communis agglutinin, type I, also precipitated the 65 000-Mr precursor in vitro and in vivo, but in addition precipitated a non-glycosylated 34 000-Mr polypeptide. This smaller protein is not a lectin subunit precursor, contradicting an earlier suggestion. It is most probably a precursor to the 2-S albumin storage proteins found in castor bean endosperm protein bodies.

  1. Wheat gluten: high molecular weight glutenin subunits--structure, genetics, and relation to dough elasticity.

    PubMed

    Anjum, Faqir Muhammad; Khan, Moazzam Rafiq; Din, Ahmad; Saeed, Muhammad; Pasha, Imran; Arshad, Muhammad Umair

    2007-04-01

    Gluten proteins, representing the major protein fraction of the starchy endosperm, are predominantly responsible for the unique position of wheat amongst cereals. These form a continuous proteinaceous matrix in the cells of the mature dry grain and form a continuous viscoelastic network during the mixing process of dough development. These viscoelastic properties underline the utilization of wheat to prepare bread and other wheat flour based foodstuffs. One group of gluten proteins is glutenin, which consists of high molecular weight (HMW) and low molecular weight (LMW) subunits. The HMW glutenin subunits (HMW-GS) are particularly important for determining dough elasticity. The common wheat possesses 3 to 5 HMW subunits encoded at the Glu-1 loci on the long arms of group 1 chromosomes (1A, 1B, and 1D). The presence of certain HMW subunits is positively correlated with good bread-making quality. Glutamine-rich repetitive sequences that comprise the central part of the HMW subunits are actually responsible for the elastic properties due to extensive arrays of interchain hydrogen bonds. Genetic engineering can be used to manipulate the amount and composition of the HMW subunits, leading to either increased dough strength or more drastic changes in gluten structure and properties.

  2. Secondary compaction after secondary porosity: Can it form a pressure seal

    SciTech Connect

    Weedman, S.D.; Brantley, S.L.; Albrecht, W. )

    1992-04-01

    Petrographic analysis of sandstones from the vicinity of a pressure seal (transition from normal to overpressure) at 5.5-km depth in the lower Tuscaloosa Formation in Louisiana documents local, high porosity above and below the seal. Packing analysis shows that compaction is greater in normally pressured, high-porosity sandstones than in overpressured, high-porosity sandstones; compaction in overpressured, high-porosity sandstones is similar to that in normally pressured, well-cemented sandstones. The authors propose that focused corrosive fluids created a zone of high secondary porosity, allowing further compaction that they call 'secondary compaction.' Secondary compaction is greater above the seal than below, suggesting that high-pressure fluid below the seal has preserved porosity and that the pressure seal became effective soon after dissolution of cement. Cuttings from the pressure-seal zone reveal an unusual texture of fragmented, pressure-solved grains and matrix, which may be a result of extensive secondary compaction.

  3. Compaction with Automatic Jog Introduction,

    DTIC Science & Technology

    1985-10-01

    The compaction algorithm This section defines mathematically the problem of compaction with auto- matk jog introduction, and presents a practical...t(5) of potential cuts of S, and usng their mutability cmndi to constrain the positiokn of modulo in S. The proof that this technique gen - erates a

  4. Fabric analysis of Allende matrix using EBSD

    NASA Astrophysics Data System (ADS)

    Watt, Lauren E.; Bland, Phil A.; Prior, Dave J.; Russell, Sara S.

    Fabric analysis of the interstitial matrix material in primitive meteorites offers a novel window on asteroid formation and evolution. Electron backscatter diffraction (EBSD) has allowed fabrics in these fine-grained materials to be visualized in detail for the first time. Our data reveal that Allende, a CV3 chondrite, possesses a uniform, planar, short-axis alignment fabric that is pervasive on a broad scale and is probably the result of deformational shortening related to impact or gravitational compaction. Interference between this matrix fabric and the larger, more rigid components, such as dark inclusions (DIs) and calcium-aluminium-rich inclusions (CAIs), has lead to the development of locally oriented and intensified matrix fabrics. In addition, DIs possess fabrics that are conformable with the broader matrix fabric. These results suggest that DIs were in situ prior to the deformational shortening event responsible for these fabrics, thus providing an argument against dark inclusions being fragments from another lithified part of the asteroid (Kojima and Tomeoka 1996; Fruland et al. 1978). Moreover, both DIs and Allende matrix are highly porous (˜25%) (Corrigan et al. 1997). Mobilizing a highly porous DI during impact-induced brecciation without imposing a fabric and incorporating it into a highly porous matrix without significantly compacting these materials is improbable. We favor a model that involves Allende DIs, CAIs, and matrix accreting together and experiencing the same deformation events.

  5. Subunit mass analysis for monitoring antibody oxidation

    PubMed Central

    Sokolowska, Izabela; Mo, Jingjie; Dong, Jia; Lewis, Michael J.; Hu, Ping

    2017-01-01

    ABSTRACT Methionine oxidation is a common posttranslational modification (PTM) of monoclonal antibodies (mAbs). Oxidation can reduce the in-vivo half-life, efficacy and stability of the product. Peptide mapping is commonly used to monitor the levels of oxidation, but this is a relatively time-consuming method. A high-throughput, automated subunit mass analysis method was developed to monitor antibody methionine oxidation. In this method, samples were treated with IdeS, EndoS and dithiothreitol to generate three individual IgG subunits (light chain, Fd’ and single chain Fc). These subunits were analyzed by reversed phase-ultra performance liquid chromatography coupled with an online quadrupole time-of-flight mass spectrometer and the levels of oxidation on each subunit were quantitated based on the deconvoluted mass spectra using the UNIFI software. The oxidation results obtained by subunit mass analysis correlated well with the results obtained by peptide mapping. Method qualification demonstrated that this subunit method had excellent repeatability and intermediate precision. In addition, UNIFI software used in this application allows automated data acquisition and processing, which makes this method suitable for high-throughput process monitoring and product characterization. Finally, subunit mass analysis revealed the different patterns of Fc methionine oxidation induced by chemical and photo stress, which makes it attractive for investigating the root cause of oxidation. PMID:28106519

  6. Subunit mass analysis for monitoring antibody oxidation.

    PubMed

    Sokolowska, Izabela; Mo, Jingjie; Dong, Jia; Lewis, Michael J; Hu, Ping

    2017-04-01

    Methionine oxidation is a common posttranslational modification (PTM) of monoclonal antibodies (mAbs). Oxidation can reduce the in-vivo half-life, efficacy and stability of the product. Peptide mapping is commonly used to monitor the levels of oxidation, but this is a relatively time-consuming method. A high-throughput, automated subunit mass analysis method was developed to monitor antibody methionine oxidation. In this method, samples were treated with IdeS, EndoS and dithiothreitol to generate three individual IgG subunits (light chain, Fd' and single chain Fc). These subunits were analyzed by reversed phase-ultra performance liquid chromatography coupled with an online quadrupole time-of-flight mass spectrometer and the levels of oxidation on each subunit were quantitated based on the deconvoluted mass spectra using the UNIFI software. The oxidation results obtained by subunit mass analysis correlated well with the results obtained by peptide mapping. Method qualification demonstrated that this subunit method had excellent repeatability and intermediate precision. In addition, UNIFI software used in this application allows automated data acquisition and processing, which makes this method suitable for high-throughput process monitoring and product characterization. Finally, subunit mass analysis revealed the different patterns of Fc methionine oxidation induced by chemical and photo stress, which makes it attractive for investigating the root cause of oxidation.

  7. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

  8. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-10-27

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

  9. Compact Dexterous Robotic Hand

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  10. Compact plasma accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor)

    2004-01-01

    A compact plasma accelerator having components including a cathode electron source, an anodic ionizing gas source, and a magnetic field that is cusped. The components are held by an electrically insulating body having a central axis, a top axial end, and a bottom axial end. The cusped magnetic field is formed by a cylindrical magnet having an axis of rotation that is the same as the axis of rotation of the insulating body, and magnetized with opposite poles at its two axial ends; and an annular magnet coaxially surrounding the cylindrical magnet, magnetized with opposite poles at its two axial ends such that a top axial end has a magnetic polarity that is opposite to the magnetic polarity of a top axial end of the cylindrical magnet. The ionizing gas source is a tubular plenum that has been curved into a substantially annular shape, positioned above the top axial end of the annular magnet such that the plenum is centered in a ring-shaped cusp of the magnetic field generated by the magnets. The plenum has one or more capillary-like orifices spaced around its top such that an ionizing gas supplied through the plenum is sprayed through the one or more orifices. The plenum is electrically conductive and is positively charged relative to the cathode electron source such that the plenum functions as the anode; and the cathode is positioned above and radially outward relative to the plenum.

  11. Compact neutron generator

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  12. Bubble migration in a compacting crystal-liquid mush

    NASA Astrophysics Data System (ADS)

    Boudreau, Alan

    2016-04-01

    Recent theoretical models have suggested that bubbles are unlikely to undergo significant migration in a compaction crystal mush by capillary invasion while the system remains partly molten. To test this, experiments of bubble migration during compaction in a crystal-liquid mush were modeled using deformable foam crystals in corn syrup in a volumetric burette, compacted with rods of varying weights. A bubble source was provided by sodium bicarbonate (Alka-Seltzer®). Large bubbles (>several crystal sizes) are pinched by the compacting matrix and become overpressured and deformed as the bubbles experience a load change from hydrostatic to lithostatic. Once they begin to move, they move much faster than the compaction-driven liquid. Bubbles that are about the same size as the crystals but larger than the narrower pore throats move by deformation or breaking into smaller bubbles as they are forced through pore restrictions. Bubbles that are less than the typical pore diameter generally move with the liquid: The liquid + bubble mixture behaves as a single phase with a lower density than the bubble-free liquid, and as a consequence it rises faster than bubble-free liquid and allows for faster compaction. The overpressure required to force a bubble through the matrix (max grain size = 5 mm) is modest, about 5 %, and it is estimated that for a grain size of 1 mm, the required overpressure would be about 25 %. Using apatite distribution in a Stillwater olivine gabbro as an analog for bubble nucleation and growth, it is suggested that relatively large bubbles initially nucleate and grow in liquid-rich channels that develop late in the compaction history. Overpressure from compaction allows bubbles to rise higher into hotter parts of the crystal pile, where they redissolve and increase the volatile content of the liquid over what it would have without the bubble migration, leading to progressively earlier vapor saturation during crystallization of the interstitial liquid

  13. Compaction managed mirror bend achromat

    DOEpatents

    Douglas, David

    2005-10-18

    A method for controlling the momentum compaction in a beam of charged particles. The method includes a compaction-managed mirror bend achromat (CMMBA) that provides a beamline design that retains the large momentum acceptance of a conventional mirror bend achromat. The CMMBA also provides the ability to tailor the system momentum compaction spectrum as desired for specific applications. The CMMBA enables magnetostatic management of the longitudinal phase space in Energy Recovery Linacs (ERLs) thereby alleviating the need for harmonic linearization of the RF waveform.

  14. Compactness of lateral shearing interferometers

    NASA Astrophysics Data System (ADS)

    Ferrec, Yann; Taboury, Jean; Sauer, Hervé; Chavel, Pierre

    2011-08-01

    Imaging lateral shearing interferometers are good candidates for airborne or spaceborne Fourier-transform spectral imaging. For such applications, compactness is one key parameter. In this article, we compare the size of four mirror-based interferometers, the Michelson interferometer with roof-top (or corner-cube) mirrors, and the cyclic interferometers with two, three, and four mirrors, focusing more particularly on the last two designs. We give the expression of the translation they induce between the two exiting rays. We then show that the cyclic interferometer with three mirrors can be made quite compact. Nevertheless, the Michelson interferometer is the most compact solution, especially for highly diverging beams.

  15. Compact, Reliable EEPROM Controller

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Kleyner, Igor

    2010-01-01

    A compact, reliable controller for an electrically erasable, programmable read-only memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells. Inadvertent writes pose risks of loss of reliability in the original space-flight application and could pose such risks in other applications. Prior EEPROM controllers are large and complex and do not provide all reasonable protections (in many cases, few or no protections) against inadvertent writes. In contrast, the present controller provides several layers of protection against inadvertent writes. The controller also incorporates a write-time monitor, enabling determination of trends in the performance of an EEPROM through all phases of testing. The controller has been designed as an integral subsystem of a system that includes not only the controller and the controlled EEPROM aboard a spacecraft but also computers in a ground control station, relatively simple onboard support circuitry, and an onboard communication subsystem that utilizes the MIL-STD-1553B protocol. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD- 1553B is commonly used in defense and space applications.) The intent was to both maximize reliability while minimizing the size and complexity of onboard circuitry. In operation, control of the EEPROM is effected via the ground computers, the MIL-STD-1553B communication subsystem, and the onboard support circuitry, all of which, in combination, provide the multiple layers of protection against inadvertent writes. There is no controller software, unlike in many prior EEPROM controllers; software can be a major contributor to unreliability, particularly in fault

  16. Compact Star Time Scales

    NASA Astrophysics Data System (ADS)

    Swank, J. H.

    1996-12-01

    A major goal of RXTE is to investigate the fastest timing signals from compact stars, especially neutron stars and black holes. Signals have now been found from many (at least nine) low mass X-ray binaries containing neutron stars in the frequency range (100-1200 Hz) expected for the rotation period of the neutron star after being spun up by accretion over a long period. The kilohertz frequency domain for these sources is simpler than the domain of oscillations below about 50 Hz in that a few isolated features can dominate over white noise. However there are three main features to consider (not all present at the same time) and at least two are quasiperiodic with varying widths and frequencies. Several models are pitting their predictions against the behavior of these features, but the bursters, especially, appear to be revealing the neutron stars's spin. It is consistent with our beliefs that no black hole candidate has shown the same complex of signals, although at least one QPO frequency of a few hundred Hz could be expected in black hole candidates by analogy to the 67 Hz observed from GRS 1915+105. The observations also provide critical tests of the interpretions of the lower frequency (5-50 Hz) QPO and the variable noise seen in both low magnetic field neutron stars and black hole candidates. The kilohertz features have not been seen from the accreting pulsars with relatively high magnetic fields, but high luminosity pulsars (such as last year's transient, GRO J1744-28) reveal signatures of the dynamic interaction between the accretion flow, the magnetic field, and perhaps the neutron star surface in addition to their coherent pulsations.

  17. Meltwater percolation and refreezing in compacting snow

    NASA Astrophysics Data System (ADS)

    Meyer, Colin; Hewitt, Ian

    2016-11-01

    Meltwater is produced on the surface of glaciers and ice sheets when the seasonal surface energy forcing warms the ice above its melting temperature. This meltwater percolates through the porous snow matrix and potentially refreezes, thereby warming the surrounding ice by the release of latent heat. Here we model this process from first principles using a continuum model. We determine the internal ice temperature and glacier surface height based on the surface forcing and the accumulation of snow. When the surface temperature exceeds the melting temperature, we compute the amount of meltwater produced and lower the glacier surface accordingly. As the meltwater is produced, we solve for its percolation through the snow. Our model results in traveling regions of meltwater with sharp fronts where refreezing occurs. We also allow the snow to compact mechanically and we analyze the interplay of compaction with meltwater percolation. We compare these models to observations of the temperature and porosity structure of the surface of glaciers and ice sheets and find excellent agreement. Our models help constrain the role that meltwater percolation and refreezing will have on ice-sheet mass balance and hence sea level. Thanks to the 2016 WHOI GFD Program, which is supported by the National Science Foundation and the Office of Naval Research.

  18. Gene targeting of CK2 catalytic subunits

    PubMed Central

    Lou, David Y.; Toselli, Paul; Landesman-Bollag, Esther; Dominguez, Isabel

    2013-01-01

    Protein kinase CK2 is a highly conserved and ubiquitous serine–threonine kinase. It is a tetrameric enzyme that is made up of two regulatory CK2β subunits and two catalytic subunits, either CK2α/CK2α, CK2α/ CK2α′, or CK2α′/CK2α′. Although the two catalytic subunits diverge in their C termini, their enzymatic activities are similar. To identify the specific function of the two catalytic subunits in development, we have deleted them individually from the mouse genome by homologous recombination. We have previously reported that CK2α′is essential for male germ cell development, and we now demonstrate that CK2α has an essential role in embryogenesis, as mice lacking CK2α die in mid-embryogenesis, with cardiac and neural tube defects. PMID:18594950

  19. Improving compact gravity inversion based on new weighting functions

    NASA Astrophysics Data System (ADS)

    Ghalehnoee, Mohammad Hossein; Ansari, Abdolhamid; Ghorbani, Ahmad

    2016-11-01

    We have developed a method to estimate the geometry, location and densities of anomalies coming from two-dimensional gravity data based on compact gravity inversion technique. Compact gravity inversion is simple, fast and user friendly but severely depends on the number of model parameters, i.e. by increasing the model parameters, the anomalies tend to concentrate near the surface. To overcome this ambiguity new weighting functions based on density contrast, depth, and compactness models have been introduced. Variable compactness factors have been defined here to get either a sharp or a smooth model based on the depth of the source or existence of prior information. Depth weighting derived from one station of gravity data whereas the effect of gravity data is two- and three-dimensional. To compensate this limitation an innovating weighting function namely kernel function has been introduced which multiplies with weight and compactness matrixes to yield a general model weighting function. The method is tested using three different sets of synthetic examples: a body at various depths (20, 40, 80 and 140 m), two bodies at the same depth but various distances to estimate lateral resolution and three bodies with negative and positive density contrast in different depths. The method is also applied to three real gravity data of Woodlawn massive sulfide body, sulfides mineralization of British Colombia and iron ore body of Missouri. The method produces solutions consistent with the known geologic attributes of the gravity sources, illustrating its potential practicality.

  20. Improving compact gravity inversion using new weighting functions

    NASA Astrophysics Data System (ADS)

    Ghalehnoee, Mohammad Hossein; Ansari, Abdolhamid; Ghorbani, Ahmad

    2017-01-01

    We have developed a method to estimate the geometry, location and densities of anomalies coming from 2-D gravity data based on compact gravity inversion technique. Compact gravity inversion is simple, fast and user friendly but severely depends on the number of model parameters, that is, by increasing the model parameters, the anomalies tend to concentrate near the surface. To overcome this ambiguity new weighting functions based on density contrast, depth, and compactness models have been introduced. Variable compactness factors have been defined here to get either a sharp or a smooth model based on the depth of the source or existence of prior information. Depth weighting derived from one station of gravity data whereas the effect of gravity data is 2-D and 3-D. To compensate this limitation an innovating weighting function namely kernel function has been introduced which multiplies with weight and compactness matrixes to yield a general model weighting function. The method is tested using three different sets of synthetic examples: a body at various depths (20, 40, 80 and 140 m), two bodies at the same depth but various distances to estimate lateral resolution and three bodies with negative and positive density contrast in different depths. The method is also applied to three real gravity data of Woodlawn massive sulphide body, sulphides mineralization of British Colombia and iron ore body of Missouri. The method produces solutions consistent with the known geologic attributes of the gravity sources, illustrating its potential practicality.

  1. Compact Shelving Ten Years Later.

    ERIC Educational Resources Information Center

    Morris, Leslie R.

    1998-01-01

    Discusses experiences at the Niagara University Library with compact shelving. Highlights include citations to other relevant articles; patron use; selection of vendor; reliability; possible problems; and installation considerations, such as floor-load requirements. (LRW)

  2. An isolated compact galaxy triplet

    NASA Astrophysics Data System (ADS)

    Feng, Shuai; Shao, Zheng-Yi; Shen, Shi-Yin; Argudo-Fernández, Maria; Wu, Hong; Lam, Man-I.; Yang, Ming; Yuan, Fang-Ting

    2016-05-01

    We report the discovery of an isolated compact galaxy triplet SDSS J084843.45+164417.3, which is first detected by the LAMOST spectral survey and then confirmed by a spectroscopic observation of the BFOSC mounted on the 2.16 meter telescope located at Xinglong Station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. It is found that this triplet is an isolated and extremely compact system, which has an aligned configuration and very small radial velocity dispersion. The member galaxies have similar colors and show marginal star formation activities. These results support the opinion that the compact triplets are well-evolved systems rather than hierarchically forming structures. This serendipitous discovery reveals the limitations of fiber spectral redshift surveys in studying such a compact system, and demonstrates the necessity of additional observations to complete the current redshift sample.

  3. A Compact Beam Measurement Setup

    NASA Astrophysics Data System (ADS)

    Graf, Urs U.

    2016-08-01

    We present the design of a compact measurement device to determine the position of a beam in a radio optical setup. The unit is used to align the Terahertz optics of the GREAT instrument on the airborne astronomical observatory SOFIA.

  4. What Is Business's Social Compact?

    ERIC Educational Resources Information Center

    Avishai, Bernard

    1994-01-01

    Under the "new" social compact, businesses must focus on continuous learning and thus have both an obligation to support teaching and an opportunity to profit from it. Learning organizations must also be teaching organizations. (SK)

  5. Anthranilate synthase subunit organization in Chromobacterium violaceum.

    PubMed

    Carminatti, C A; Oliveira, I L; Recouvreux, D O S; Antônio, R V; Porto, L M

    2008-09-16

    Tryptophan is an aromatic amino acid used for protein synthesis and cellular growth. Chromobacterium violaceum ATCC 12472 uses two tryptophan molecules to synthesize violacein, a secondary metabolite of pharmacological interest. The genome analysis of this bacterium revealed that the genes trpA-F and pabA-B encode the enzymes of the tryptophan pathway in which the first reaction is the conversion of chorismate to anthranilate by anthranilate synthase (AS), an enzyme complex. In the present study, the organization and structure of AS protein subunits from C. violaceum were analyzed using bioinformatics tools available on the Web. We showed by calculating molecular masses that AS in C. violaceum is composed of alpha (TrpE) and beta (PabA) subunits. This is in agreement with values determined experimentally. Catalytic and regulatory sites of the AS subunits were identified. The TrpE and PabA subunits contribute to the catalytic site while the TrpE subunit is involved in the allosteric site. Protein models for the TrpE and PabA subunits were built by restraint-based homology modeling using AS enzyme, chains A and B, from Salmonella typhimurium (PDB ID 1I1Q).

  6. Compact Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1988-01-01

    Longitudinal pumping by laser diodes increases efficiency. Improved holmium:yttrium lithium fluoride laser radiates as much as 56 mW of power at wavelength of 2.1 micrometer. New Ho:YLF laser more compact and efficient than older, more powerful devices of this type. Compact, efficient Ho:YLF laser based on recent successes in use of diode lasers to pump other types of solid-state lasers.

  7. Compaction with automatic jog introduction

    NASA Astrophysics Data System (ADS)

    Maley, F. M.

    1985-10-01

    A novel polynomial-time algorithm for compacting a VLSI layout is presented. Compared to previous algorithms, the algorithm promises to produce higher quality output while reducing the need for designer intervention. The performance gain is realized by converting wires into constraints on the positions of the active devices. These constraints can be solved by graph-theoretic techniques to yield optimal positions for chip components. A single-layer router is then used to restore the wires to the layout, using as many as jogs as necessary. An automated compaction procedure is an effective tool for cutting production costs of a VLSI circuit at low cost to the designer, because the yield of fabricated chips is strongly dependent on the total circuit area. Sect 1 is an introduction. Sect 2 states the definitions and theoretical results that underlie the new compaction method. Sect 3 shows how the circuit layout is converted to a data structure appropriate for compaction, and Sect 4 details the body of the compaction algorithm. Sect 5 covers several improvements to the algorithm that should make it run considerably faster. Sect 6 comments on the algorithms of results, and a discussion of the practical value of the compaction algorithm.

  8. High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, John D.; Spitzig, William A.; Gibson, Edwin D.; Anderson, Iver E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

  9. High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

  10. Protein synthesis by ribosomes with tethered subunits.

    PubMed

    Orelle, Cédric; Carlson, Erik D; Szal, Teresa; Florin, Tanja; Jewett, Michael C; Mankin, Alexander S

    2015-08-06

    The ribosome is a ribonucleoprotein machine responsible for protein synthesis. In all kingdoms of life it is composed of two subunits, each built on its own ribosomal RNA (rRNA) scaffold. The independent but coordinated functions of the subunits, including their ability to associate at initiation, rotate during elongation, and dissociate after protein release, are an established model of protein synthesis. Furthermore, the bipartite nature of the ribosome is presumed to be essential for biogenesis, since dedicated assembly factors keep immature ribosomal subunits apart and prevent them from translation initiation. Free exchange of the subunits limits the development of specialized orthogonal genetic systems that could be evolved for novel functions without interfering with native translation. Here we show that ribosomes with tethered and thus inseparable subunits (termed Ribo-T) are capable of successfully carrying out protein synthesis. By engineering a hybrid rRNA composed of both small and large subunit rRNA sequences, we produced a functional ribosome in which the subunits are covalently linked into a single entity by short RNA linkers. Notably, Ribo-T was not only functional in vitro, but was also able to support the growth of Escherichia coli cells even in the absence of wild-type ribosomes. We used Ribo-T to create the first fully orthogonal ribosome-messenger RNA system, and demonstrate its evolvability by selecting otherwise dominantly lethal rRNA mutations in the peptidyl transferase centre that facilitate the translation of a problematic protein sequence. Ribo-T can be used for exploring poorly understood functions of the ribosome, enabling orthogonal genetic systems, and engineering ribosomes with new functions.

  11. Compact Intracloud Discharges

    SciTech Connect

    Smith, David A.

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  12. Compact intracloud discharges

    NASA Astrophysics Data System (ADS)

    Smith, David Adam

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackbeard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackbeard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackbeard observations. On two occasions, the ground-based systems and Blackbeard even recorded emissions that were produced by the same exact events. From the ground-based observations, it has been determined that TIPP events are produced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDs, an acronym for compact intracloud discharges. During the summer of 1996, ground- based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDs. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDs were recorded from three

  13. Natural examples of Valdivia compact spaces

    NASA Astrophysics Data System (ADS)

    Kalenda, Ondrej F. K.

    2008-04-01

    We collect examples of Valdivia compact spaces, their continuous images and associated classes of Banach spaces which appear naturally in various branches of mathematics. We focus on topological constructions generating Valdivia compact spaces, linearly ordered compact spaces, compact groups, L1 spaces, Banach lattices and noncommutative L1 spaces.

  14. Crystal structure of the C-terminal domain of the RAP74 subunit of human transcription factor IIF

    SciTech Connect

    Kamada, Katsuhiko; De Angelis, Jacqueline; Roeder, Robert G.; Burley, Stephen K.

    2012-12-13

    The x-ray structure of a C-terminal fragment of the RAP74 subunit of human transcription factor (TF) IIF has been determined at 1.02-{angstrom} resolution. The {alpha}/{beta} structure is strikingly similar to the globular domain of linker histone H5 and the DNA-binding domain of hepatocyte nuclear factor 3{gamma} (HNF-3{gamma}), making it a winged-helix protein. The surface electrostatic properties of this compact domain differ significantly from those of bona fide winged-helix transcription factors (HNF-3{gamma} and RFX1) and from the winged-helix domains found within the RAP30 subunit of TFIIF and the {beta} subunit of TFIIE. RAP74 has been shown to interact with the TFIIF-associated C-terminal domain phosphatase FCP1, and a putative phosphatase binding site has been identified within the RAP74 winged-helix domain.

  15. Mechanical and microstructural characterization of Al7075/SiC nanocomposites fabricated by dynamic compaction

    NASA Astrophysics Data System (ADS)

    Atrian, A.; Majzoobi, G. H.; Enayati, M. H.; Bakhtiari, H.

    2014-03-01

    This paper describes the synthesis of Al7075 metal matrix composites reinforced with SiC, and the characterization of their microstructure and mechanical behavior. The mechanically milled Al7075 micron-sized powder and SiC nanoparticles are dynamically compacted using a drop hammer device. This compaction is performed at different temperatures and for various volume fractions of SiC nanoparticles. The relative density is directly related to the compaction temperature rise and indirectly related to the content of SiC nanoparticle reinforcement, respectively. Furthermore, increasing the amount of SiC nanoparticles improves the strength, stiffness, and hardness of the compacted specimens. The increase in hardness and strength may be attributed to the inherent hardness of the nanoparticles, and other phenomena such as thermal mismatch and crack shielding. Nevertheless, clustering of the nanoparticles at aluminum particle boundaries make these regions become a source of concentrated stress, which reduces the load carrying capacity of the compacted nanocomposite.

  16. Viral RNAs Are Unusually Compact

    PubMed Central

    Gopal, Ajaykumar; Egecioglu, Defne E.; Yoffe, Aron M.; Ben-Shaul, Avinoam; Rao, Ayala L. N.; Knobler, Charles M.; Gelbart, William M.

    2014-01-01

    A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly. PMID:25188030

  17. Viral RNAs are unusually compact.

    PubMed

    Gopal, Ajaykumar; Egecioglu, Defne E; Yoffe, Aron M; Ben-Shaul, Avinoam; Rao, Ayala L N; Knobler, Charles M; Gelbart, William M

    2014-01-01

    A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly.

  18. Drosophila laminin: sequence of B2 subunit and expression of all three subunits during embryogenesis

    PubMed Central

    1989-01-01

    In a previous study, we described the cloning of the genes encoding the three subunits of Drosophila laminin, a substrate adhesion molecule, and the cDNA sequence of the B1 subunit (Montell and Goodman, 1988). This analysis revealed the similarity of Drosophila laminin with the mouse and human complexes in subunit composition, domain structure, and amino acid sequence. In this paper, we report the deduced amino acid sequence of the B2 subunit. We then describe the expression and tissue distribution of the three subunits of laminin during Drosophila embryogenesis using both in situ hybridization and immunolocalization techniques, with particular emphasis on its expression in and around the developing nervous system. PMID:2808533

  19. Compact orthogonal NMR field sensor

    DOEpatents

    Gerald, II, Rex E.; Rathke, Jerome W.

    2009-02-03

    A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

  20. Compact accelerator for medical therapy

    DOEpatents

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  1. Compact intermediates in RNA folding

    SciTech Connect

    Woodson, S.A.

    2011-12-14

    Large noncoding RNAs fold into their biologically functional structures via compact yet disordered intermediates, which couple the stable secondary structure of the RNA with the emerging tertiary fold. The specificity of the collapse transition, which coincides with the assembly of helical domains, depends on RNA sequence and counterions. It determines the specificity of the folding pathways and the magnitude of the free energy barriers to the ensuing search for the native conformation. By coupling helix assembly with nascent tertiary interactions, compact folding intermediates in RNA also play a crucial role in ligand binding and RNA-protein recognition.

  2. Compact monolithic capacitive discharge unit

    DOEpatents

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  3. Compressibility Characteristics of Compacted Snow

    DTIC Science & Technology

    1976-06-01

    Cornpressibility characteristics 7Jj i C’p of compacted snowifAG2� 004 t Cover: ~ ~ ~ ~ ~ ~ ~ ~ a - Thn***o htgrp fpoyrsaliekAmgife i ote rm...nwcmrse to7 asa 10 Phtgahb nhn Gow1 CRREL Report 76-21 Compressibility characteristics of compacted snow %i" Gunars Abele and Anthony J. Cow I ~ June 1976 A ...c , I fu. A AD,:j ly M3rs CORPS OF ENGINEERS, U.S. ARMY COLD REGIONS RESEARCH AND ENGINEERZ]NG LABORATORY HANOVER, NEW HAMPSHIRE Approved for public

  4. 76 FR 66326 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... address this session of the Council should notify the Federal Bureau Of Investigation (FBI) Compact..., FBI Compact Officer, Compact Council Office, Module D3, 1000 Custer Hollow Road, Clarksburg,...

  5. 75 FR 62568 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... of the Council should notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr. Gary S..., FBI Compact Officer, Compact Council Office, Module D3, 1000 Custer Hollow Road, Clarksburg,...

  6. Compact Photon Source Conceptual Design

    SciTech Connect

    Degtyarenko, Pavel V.; Wojtsekhowski, Bogdan B.

    2016-04-01

    We describe options for the production of an intense photon beam at the CEBAF Hall D Tagger facility, needed for creating a high-quality secondary K 0 L delivered to the Hall D detector. The conceptual design for the Compact Photon Source apparatus is presented.

  7. Upwind Compact Finite Difference Schemes

    NASA Astrophysics Data System (ADS)

    Christie, I.

    1985-07-01

    It was shown by Ciment, Leventhal, and Weinberg ( J. Comput. Phys.28 (1978), 135) that the standard compact finite difference scheme may break down in convection dominated problems. An upwinding of the method, which maintains the fourth order accuracy, is suggested and favorable numerical results are found for a number of test problems.

  8. Subunit Recombinant Vaccine Protects Against Monkeypox

    DTIC Science & Technology

    2006-05-27

    Subunit Recombinant Vaccine Protects against Monkeypox1 Jean-Michel Heraud,* Yvette Edghill-Smith,*† Victor Ayala,‡ Irene Kalisz,‡ Janie Parrino ...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Heraud, JM Edghill-Smith, Y Ayala, V Kalisz, I Parrino , J Kalyanaraman, VS Manischewitz, J King

  9. Compact CFB: The next generation CFB boiler

    SciTech Connect

    Utt, J.

    1996-12-31

    The next generation of compact circulating fluidized bed (CFB) boilers is described in outline form. The following topics are discussed: compact CFB = pyroflow + compact separator; compact CFB; compact separator is a breakthrough design; advantages of CFB; new design with substantial development history; KUHMO: successful demo unit; KUHMO: good performance over load range with low emissions; KOKKOLA: first commercial unit and emissions; KOKKOLA: first commercial unit and emissions; compact CFB installations; next generation CFB boiler; grid nozzle upgrades; cast segmented vortex finders; vortex finder installation; ceramic anchors; pre-cast vertical bullnose; refractory upgrades; and wet gunning.

  10. Fluorescently tagged laminin subunits facilitate analyses of the properties, assembly and processing of laminins in live and fixed lung epithelial cells and keratinocytes.

    PubMed

    Hopkinson, Susan B; DeBiase, Phillip J; Kligys, Kristina; Hamill, Kevin; Jones, Jonathan C R

    2008-09-01

    Recent analyses of collagen, elastin and fibronectin matrix assembly, organization and remodeling have been facilitated by the use of tagged proteins that can be visualized without the need for antibody labeling. Here, we report the generation of C-terminal tagged, full-length and "processed" (alpha3DeltaLG4-5) human alpha3 as well as C-terminal tagged, full-length human beta3 laminin subunits in adenoviral vectors. Human epidermal keratinocytes (HEKs) and human bronchial epithelial (BEP2D) cells, which assemble laminin-332-rich matrices, as well as primary rat lung alveolar type II (ATII) cells, which elaborate a fibrous network rich in laminin-311, were infected with adenovirus encoding the tagged human laminin subunits. In HEKs and BEP2D cells, tagged, full-length alpha3, alpha3DeltaLG4-5 and beta3 laminin subunits incorporate into arrays of matrix organized into patterns that are comparable to those observed when such cells are stained using laminin-332 subunit antibody probes. Moreover, HEKs and BEP2Ds move over these tagged, laminin-332-rich matrix arrays. We have also used the tagged beta3 laminin subunit-containing matrices to demonstrate that assembled laminin-332 arrays influence laminin matrix secretion and/or assembly. In the case of rat ATII cells, although tagged alpha3 laminin subunits are not detected in the matrix of rat ATII cells infected with virus encoding full-length human alpha3 laminin protein, processed human alpha3 laminin subunits are incorporated into an extracellular fibrous array. We discuss how these novel laminin reagents can be used to study the organization, processing and assembly of laminin matrices and how they provide new insights into the potential functional importance of laminin fragments.

  11. Assignment of the gene encoding the [beta]-subunit of the electron-transfer flavoprotein (ETFB) to human chromosome 19q13. 3

    SciTech Connect

    Antonacci, R. ); Colombo, I.; Volta, M.; DiDonato, S.; Finocchiaro, G. ); Archidiacono, N.; Rocchi, M. )

    1994-01-01

    The electron-transfer flavoprotein (ETF), located in the mitochondrial matrix, is a nuclear-encoded enzyme delivering to the respiratory chain electrons by straight-chain acyl-CoA dehydrogenases and other dehydrogenases. ETF is composed of a 35-kDa [alpha]-subunit that is cleaved to a 32-kDa protein during mitochondrial import (ETFA) and a [beta]-subunit that reaches the mitochondrion unmodified (ETFB). The cDNA encoding both these subunits has been cloned and sequenced. 14 refs., 1 fig.

  12. Detection of constitutive heterodimerization of the integrin Mac-1 subunits by fluorescence resonance energy transfer in living cells

    SciTech Connect

    Fu Guo; Yang Huayan; Wang Chen; Zhang Feng; You Zhendong; Wang Guiying; He Cheng; Chen Yizhang . E-mail: yzchen0928@yahoo.com; Xu Zhihan . E-mail: zzxu@mail.shcnc.ac.cn

    2006-08-04

    Macrophage differentiation antigen associated with complement three receptor function (Mac-1) belongs to {beta}{sub 2} subfamily of integrins that mediate important cell-cell and cell-extracellular matrix interactions. Biochemical studies have indicated that Mac-1 is a constitutive heterodimer in vitro. Here, we detected the heterodimerization of Mac-1 subunits in living cells by means of two fluorescence resonance energy transfer (FRET) techniques (fluorescence microscopy and fluorescence spectroscopy) and our results demonstrated that there is constitutive heterodimerization of the Mac-1 subunits and this constitutive heterodimerization of the Mac-1 subunits is cell-type independent. Through FRET imaging, we found that heterodimers of Mac-1 mainly localized in plasma membrane, perinuclear, and Golgi area in living cells. Furthermore, through analysis of the estimated physical distances between cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) fused to Mac-1 subunits, we suggested that the conformation of Mac-1 subunits is not affected by the fusion of CFP or YFP and inferred that Mac-1 subunits take different conformation when expressed in Chinese hamster ovary (CHO) and human embryonic kidney (HEK) 293T cells, respectively.

  13. High Impact Technology Compact Combustion (HITCC) Compact Core Technologies

    DTIC Science & Technology

    2016-01-01

    correlation as the chemical “timescale.” The resulting correlation equation is Eq 22. Including laminar flame speed improved the R-squared value from...including: 1) ultra-compact combustors, 2) inter-turbine burner concepts, 3) bluff-body stabilized turbulent flames, 4) well-stirred reactors for... chemical kinetics, and 5) detonation-stabilized turbulent flames. Lean blowout data was collected on propane and jet fuel bluff-body stabilized flames

  14. On the spline-based wavelet differentiation matrix

    NASA Technical Reports Server (NTRS)

    Jameson, Leland

    1993-01-01

    The differentiation matrix for a spline-based wavelet basis is constructed. Given an n-th order spline basis it is proved that the differentiation matrix is accurate of order 2n + 2 when periodic boundary conditions are assumed. This high accuracy, or superconvergence, is lost when the boundary conditions are no longer periodic. Furthermore, it is shown that spline-based bases generate a class of compact finite difference schemes.

  15. Hybrid matrix fiber composites

    DOEpatents

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2003-07-15

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  16. Subunit-selective proteasome activity profiling uncovers uncoupled proteasome subunit activities during bacterial infections.

    PubMed

    Misas-Villamil, Johana C; van der Burgh, Aranka M; Grosse-Holz, Friederike; Bach-Pages, Marcel; Kovács, Judit; Kaschani, Farnusch; Schilasky, Sören; Emon, Asif Emran Khan; Ruben, Mark; Kaiser, Markus; Overkleeft, Hermen S; van der Hoorn, Renier A L

    2017-01-24

    The proteasome is a nuclear - cytoplasmic proteolytic complex involved in nearly all regulatory pathways in plant cells. The three different catalytic activities of the proteasome can have different functions but tools to monitor and control these subunits selectively are not yet available in plant science. Here, we introduce subunit-selective inhibitors and dual-color fluorescent activity-based probes for studying two of the three active catalytic subunits of the plant proteasome. We validate these tools in two model plants and use this to study the proteasome during plant-microbe interactions. Our data reveals that Nicotiana benthamiana incorporates two different paralogs of each catalytic subunit into active proteasomes. Interestingly, both β1 and β5 activities are significantly increased upon infection with pathogenic Pseudomonas syringae pv. tomato DC3000 lacking hopQ1-1 (PtoDC3000(ΔhQ)) whilst the activity profile of the β1 subunit changes. Infection with wild-type PtoDC3000 causes proteasome activities that range from strongly induced β1 and β5 activities to strongly suppressed β5 activities, revealing that β1 and β5 activities can be uncoupled during bacterial infection. These selective probes and inhibitors are now available to the plant science community and can be widely and easily applied to study the activity and role of the different catalytic subunits of the proteasome in different plant species. This article is protected by copyright. All rights reserved.

  17. Invariant distributions on compact homogeneous spaces

    SciTech Connect

    Gorbatsevich, V V

    2013-12-31

    In this paper, we study distributions on compact homogeneous spaces, including invariant distributions and also distributions admitting a sub-Riemannian structure. We first consider distributions of dimension 1 and 2 on compact homogeneous spaces. After this, we study the cases of compact homogeneous spaces of dimension 2, 3, and 4 in detail. Invariant distributions on simply connected compact homogeneous spaces are also treated. Bibliography: 18 titles.

  18. Homodimerization of the p51 Subunit of HIV-1 Reverse Transcriptase

    SciTech Connect

    Zheng, X.; Mueller, G; Cuneo, M; DeRose, E; London, R

    2010-01-01

    The dimerization of HIV reverse transcriptase (RT), required to obtain the active form of the enzyme, is influenced by mutations, non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleotide substrates, Mg ions, temperature, and specifically designed dimerization inhibitors. In this study, we have utilized nuclear magnetic resonance (NMR) spectroscopy of the [methyl-{sup 13}C]methionine-labeled enzyme and small-angle X-ray scattering (SAXS) to investigate how several of these factors influence the dimerization behavior of the p51 subunit. The {sup 1}H-{sup 13}C HSQC spectrum of p51 obtained at micromolar concentrations indicates that a significant fraction of the p51 adopts a 'p66-like' conformation. SAXS data obtained for p51 samples were used to determine the fractions of monomer and dimer in the sample and to evaluate the conformation of the fingers/thumb subdomain. All of the p51 monomer observed was found to adopt the compact, 'p51C' conformation observed for the p51 subunit in the RT heterodimer. The NMR and SAXS data indicate that the p51 homodimer adopts a structure that is similar to the p66/p51 heterodimer, with one p51C subunit and a second p51 subunit in an extended, 'p51E' conformation that resembles the p66 subunit of the heterodimer. The fractional dimer concentration and the fingers/thumb orientation are found to depend strongly on the experimental conditions and exhibit a qualitative dependence on nevirapine and ionic strength (KCl) that is similar to the behavior reported for the heterodimer and the p66 homodimer. The L289K mutation interferes with p51 homodimer formation as it does with formation of the heterodimer, despite its location far from the dimer interface. This effect is readily interpreted in terms of a conformational selection model, in which p51{sub L289K} has a much greater preference for the compact, p51C conformation. A reduced level of dimer formation then results from the reduced ratio of the p51E{sub L289K} to p51C

  19. Compact Ocean Models Enable Onboard AUV Autonomy and Decentralized Adaptive Sampling

    DTIC Science & Technology

    2010-09-30

    observed variables and state variable in an NPZD model of Monterey Bay. Multivariate coupling was characterized by the state covariance matrix computed...large phytoplankton stocks in a numerical model . Our analysis also highlighted the need to better characterize zooplankton stocks in an NPZD model ...DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Compact Ocean Models Enable Onboard AUV Autonomy and

  20. Heat-Transfer and Friction Factor Design Data for All-Metal Compact Heat Exchangers

    DTIC Science & Technology

    1989-03-01

    modeled as a "matrix," similar to a porous media , but the correlation parameters generated didn’t describe the system correctly. Finally, the plate...40. 3. WI.M. Kays, and A.L. London, Compact Heat Exchangers, ?nd Edition, McGraw Hill, New York, 1964. 4. McAdams, Heat Transmision , 3rd Edition

  1. High-Accuracy Compact MacCormack-Type Schemes for Computational Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Hixon, R.; Turkel, E.

    1998-01-01

    Using MacCormack-type methods, a new class of highly accurate compact MacCormack-type schemes is derived which does not require a tridiagonal matrix inversion to obtain the spatial derivatives. Two examples are shown, and results of these schemes for three linear and nonlinear CAA Benchmark Problems are presented.

  2. An uncoupling channel within the c-subunit ring of the F1FO ATP synthase is the mitochondrial permeability transition pore.

    PubMed

    Alavian, Kambiz N; Beutner, Gisela; Lazrove, Emma; Sacchetti, Silvio; Park, Han-A; Licznerski, Pawel; Li, Hongmei; Nabili, Panah; Hockensmith, Kathryn; Graham, Morven; Porter, George A; Jonas, Elizabeth A

    2014-07-22

    Mitochondria maintain tight regulation of inner mitochondrial membrane (IMM) permeability to sustain ATP production. Stressful events cause cellular calcium (Ca(2+)) dysregulation followed by rapid loss of IMM potential known as permeability transition (PT), which produces osmotic shifts, metabolic dysfunction, and cell death. The molecular identity of the mitochondrial PT pore (mPTP) was previously unknown. We show that the purified reconstituted c-subunit ring of the FO of the F1FO ATP synthase forms a voltage-sensitive channel, the persistent opening of which leads to rapid and uncontrolled depolarization of the IMM in cells. Prolonged high matrix Ca(2+) enlarges the c-subunit ring and unhooks it from cyclophilin D/cyclosporine A binding sites in the ATP synthase F1, providing a mechanism for mPTP opening. In contrast, recombinant F1 beta-subunit applied exogenously to the purified c-subunit enhances the probability of pore closure. Depletion of the c-subunit attenuates Ca(2+)-induced IMM depolarization and inhibits Ca(2+) and reactive oxygen species-induced cell death whereas increasing the expression or single-channel conductance of the c-subunit sensitizes to death. We conclude that a highly regulated c-subunit leak channel is a candidate for the mPTP. Beyond cell death, these findings also imply that increasing the probability of c-subunit channel closure in a healthy cell will enhance IMM coupling and increase cellular metabolic efficiency.

  3. Dynamics of compact homogeneous universes

    SciTech Connect

    Tanimoto, M.; Koike, T.; Hosoya, A.

    1997-01-01

    A complete description of dynamics of compact locally homogeneous universes is given, which, in particular, includes explicit calculations of Teichm{umlt u}ller deformations and careful counting of dynamical degrees of freedom. We regard each of the universes as a simply connected four-dimensional space{endash}time with identifications by the action of a discrete subgroup of the isometry group. We then reduce the identifications defined by the space{endash}time isometries to ones in a homogeneous section, and find a condition that such spatial identifications must satisfy. This is essential for explicit construction of compact homogeneous universes. Some examples are demonstrated for Bianchi II, VI{sub 0}, VII{sub 0}, and I universal covers. {copyright} {ital 1997 American Institute of Physics.}

  4. Marginally compact hyperbranched polymer trees.

    PubMed

    Dolgushev, M; Wittmer, J P; Johner, A; Benzerara, O; Meyer, H; Baschnagel, J

    2017-03-29

    Assuming Gaussian chain statistics along the chain contour, we generate by means of a proper fractal generator hyperbranched polymer trees which are marginally compact. Static and dynamical properties, such as the radial intrachain pair density distribution ρpair(r) or the shear-stress relaxation modulus G(t), are investigated theoretically and by means of computer simulations. We emphasize that albeit the self-contact density diverges logarithmically with the total mass N, this effect becomes rapidly irrelevant with increasing spacer length S. In addition to this it is seen that the standard Rouse analysis must necessarily become inappropriate for compact objects for which the relaxation time τp of mode p must scale as τp ∼ (N/p)(5/3) rather than the usual square power law for linear chains.

  5. Compact portable diffraction moire interferometer

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1989-01-01

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observation means including film and video cameras may be used to view and record the resultant fringe patterns.

  6. Compact portable diffraction moire interferometer

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1988-05-23

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observations means including film and video cameras may be used to view and record the resultant fringe patterns. 7 figs.

  7. Compaction of Global Data Fields

    DTIC Science & Technology

    1990-05-01

    AD- A225 856 Naval Oceanographic and Technical Note 27 Atmospheric Research Laboratory May 1990 nC II FILF Copy Compaction of Global Data Fields A. H...IU 0 Ij P\\ I -’ as - -O - - YrŘ 5/ ii Ch Cc I 4" IIJ /1 1 att, 14 o c qu 0 in 64 low Ln u Ln U Ln LLJ KA E0 U-j u odd LD x 0 LL- cr - -1 Ap 0 Ln 00

  8. Compact magnetic energy storage module

    DOEpatents

    Prueitt, Melvin L.

    1994-01-01

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

  9. Compact optical microfiber phase modulator.

    PubMed

    Zhang, Xueliang; Belal, M; Chen, G Y; Song, Zhangqi; Brambilla, G; Newson, T P

    2012-02-01

    A compact optical microfiber phase modulator with MHz bandwidth is presented. A micrometer-diameter microfiber is wound on a millimeter-diameter piezoelectric ceramic rod with two electrodes. When a voltage is applied to the piezoelectric ceramic, the rod is strained, leading to a phase change along the microfiber; because of the small size, the optical microfiber phase modulator can have as high as a few MHz bandwidth response.

  10. Nuclear Physics for Compact Stars

    SciTech Connect

    Baldo, M.

    2009-05-04

    A brief overview is given of the different lines of research developed under the INFN project 'Compact Stellar Objects and Dense Hadronic Matter' (acronym CT51). The emphasis of the project is on the structure of Neutron Stars (NS) and related objects. Starting from crust, the different Nuclear Physics problems are described which are encountered going inside a NS down to its inner core. The theoretical challenges and the observational inputs are discussed in some detail.

  11. COMB: Compact embedded object simulations

    NASA Astrophysics Data System (ADS)

    McEwen, Jason D.

    2016-06-01

    COMB supports the simulation on the sphere of compact objects embedded in a stochastic background process of specified power spectrum. Support is provided to add additional white noise and convolve with beam functions. Functionality to support functions defined on the sphere is provided by the S2 code (ascl:1606.008); HEALPix (ascl:1107.018) and CFITSIO (ascl:1010.001) are also required.

  12. Compact magnetic energy storage module

    DOEpatents

    Prueitt, M.L.

    1994-12-20

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

  13. Compact planar microwave blocking filters

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  14. Compact Stellarator Path to DEMO

    NASA Astrophysics Data System (ADS)

    Lyon, J. F.

    2007-11-01

    Issues for a DEMO reactor are sustaining an ignited/high-Q plasma in steady state, avoiding disruptions and large variations in power flux to the wall, adequate confinement of thermal plasma and alpha-particles, control of a burning plasma, particle and power handling, etc. Compact stellarators have key advantages -- steady-state high-plasma-density operation without external current drive or disruptions, stability without a close conducting wall or active feedback systems, and low recirculating power -- in addition to moderate plasma aspect ratio, good confinement, and high-beta potential. The ARIES-CS study established that compact stellarators can be competitive with tokamaks as reactors. Many of the issues for a compact stellarator DEMO can be answered using results from large tokamaks, ITER D-T experiments and fusion materials, technology and component development programs, in addition to stellarators in operation, under construction or in development. However, a large next-generation stellarator will be needed to address some physics issues: size scaling and confinement at higher parameters, burning plasma issues, and operation with a strongly radiative divertor. Technology issues include simpler coils, structure, and divertor fabrication, and better cost information.

  15. Compaction with automatic jog introduction

    NASA Astrophysics Data System (ADS)

    Maley, F. M.

    1986-05-01

    This thesis presents an algorithm for one-dimensional compaction of VLSI layouts. It differs from older methods in treating wires not as objects to be moved, but as constraints on the positions of other circuit components. These constraints are determined for each wiring layer using the theory of planar routing. Assuming that the wiring layers can be treated independently, the algorithm minimizes the width of a layout, automatically inserting as many jogs in wires as necessary. It runs in time 0(n4) on input of size n. Several heuristics are suggested for improving the algorithm's practical performance. The compaction algorithm takes as input a data structure called a sketch, which explicitly distinguishes between flexible components (wires) and rigid components (modules). The algorithm first finds constraints on the positions of modules that ensure enough space is left for wires. Next, it solves the system of constraints by a standard graph-theoretic technique, obtaining a placement for the modules. It then relies on a single-layer router to restore the wires to each circuit layer. An efficient single-layer router is already known; it is able to minimize the length of every wire, though not the number of jogs. As given, the compaction algorithm applies only to a VLSI model that requires wires to run a rectilinear grid. This restriction is needed only because the theory of planar routing (and single-layer routers) has not yet been extended to other models.

  16. 76 FR 20044 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  17. 75 FR 17161 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... purpose of this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact)....

  18. Graphite matrix materials for nuclear waste isolation

    SciTech Connect

    Morgan, W.C.

    1981-06-01

    At low temperatures, graphites are chemically inert to all but the strongest oxidizing agents. The raw materials from which artificial graphites are produced are plentiful and inexpensive. Morover, the physical properties of artificial graphites can be varied over a very wide range by the choice of raw materials and manufacturing processes. Manufacturing processes are reviewed herein, with primary emphasis on those processes which might be used to produce a graphite matrix for the waste forms. The approach, recommended herein, involves the low-temperature compaction of a finely ground powder produced from graphitized petroleum coke. The resultant compacts should have fairly good strength, low permeability to both liquids and gases, and anisotropic physical properties. In particular, the anisotropy of the thermal expansion coefficients and the thermal conductivity should be advantageous for this application. With two possible exceptions, the graphite matrix appears to be superior to the metal alloy matrices which have been recommended in prior studies. The two possible exceptions are the requirements on strength and permeability; both requirements will be strongly influenced by the containment design, including the choice of materials and the waste form, of the multibarrier package. Various methods for increasing the strength, and for decreasing the permeability of the matrix, are reviewed and discussed in the sections in Incorporation of Other Materials and Elimination of Porosity. However, it would be premature to recommend a particular process until the overall multi-barrier design is better defined. It is recommended that increased emphasis be placed on further development of the low-temperature compacted graphite matrix concept.

  19. Subunit organization in cytoplasmic dynein subcomplexes

    PubMed Central

    King, Stephen J.; Bonilla, Myriam; Rodgers, Michael E.; Schroer, Trina A.

    2002-01-01

    Because cytoplasmic dynein plays numerous critical roles in eukaryotic cells, determining the subunit composition and the organization and functions of the subunits within dynein are important goals. This has been difficult partly because of accessory polypeptide heterogeneity of dynein populations. The motor domain containing heavy chains of cytoplasmic dynein are associated with multiple intermediate, light intermediate, and light chain accessory polypeptides. We examined the organization of these subunits within cytoplasmic dynein by separating the molecule into two distinct subcomplexes. These subcomplexes were competent to reassemble into a molecule with dynein-like properties. One subcomplex was composed of the dynein heavy and light intermediate chains whereas the other subcomplex was composed of the intermediate and light chains. The intermediate and light chain subcomplex could be further separated into two pools, only one of which contained dynein light chains. The two pools had distinct intermediate chain compositions, suggesting that intermediate chain isoforms have different light chain–binding properties. When the two intermediate chain pools were characterized by analytical velocity sedimentation, at least four molecular components were seen: intermediate chain monomers, intermediate chain dimers, intermediate chain monomers with bound light chains, and a mixture of intermediate chain dimers with assorted bound light chains. These data provide new insights into the compositional heterogeneity and assembly of the cytoplasmic dynein complex and suggest that individual dynein molecules have distinct molecular compositions in vivo. PMID:11967380

  20. DNA sequences, recombinant DNA molecules and processes for producing the A and B subunits of cholera toxin and preparations containing so-obtained subunit or subunits

    SciTech Connect

    Harford, N.; De Wilde, M.

    1987-05-19

    A recombinant DNA molecule is described comprising at least a portion coding for subunits A and B of cholera toxin, or a fragment or derivative of the portion wherein the fragment or derivative codes for a polypeptide have an activity which can induce an immune response to subunit A; can induce an immune response to subunit A and cause epithelial cell penetration and the enzymatic effect leading to net loss of fluid into the gut lumen; can bind to the membrane receptor for the B subunit of cholera toxin; can induce an immune response to subunit B; can induce an immune response to subunit B and bind to the membrane receptor; or has a combination of the activities.

  1. The compact conformation of fibronectin is determined by intramolecular ionic interactions.

    PubMed

    Johnson, K J; Sage, H; Briscoe, G; Erickson, H P

    1999-05-28

    Fibronectin exists in a compact or extended conformation, depending upon environmental pH and salt concentration. Using recombinant fragments expressed in bacteria and baculovirus, we determined the domains responsible for producing fibronectin's compact conformation. Our velocity and equilibrium sedimentation data show that FN2-14 (a protein containing FN-III domains 2 through 14) forms dimers in low salt. Experiments with smaller fragments indicates that the compact conformation is produced by binding of FN12-14 of one subunit to FN2-3 of the other subunit in the dimer. The binding is weakened at higher salt concentrations, implying an electrostatic interaction. Furthermore, segment FN7-14+A, which contains the alternatively spliced A domain between FN11 and 12, forms dimers, whereas FN7-14 without A does not. Segment FN12-14+A also forms dimers, but the isolated A domain does not. These data imply an association of domain A with FN12-14, and the presence of A may favor an open conformation by competing with FN2-3 for binding to FN12-14.

  2. Differential accumulation of ribonucleotide reductase subunits in clam oocytes: the large subunit is stored as a polypeptide, the small subunit as untranslated mRNA

    PubMed Central

    1986-01-01

    Within minutes of fertilization of clam oocytes, translation of a set of maternal mRNAs is activated. One of the most abundant of these stored mRNAs encodes the small subunit of ribonucleotide reductase (Standart, N. M., S. J. Bray, E. L. George, T. Hunt, and J. V. Ruderman, 1985, J. Cell Biol., 100:1968-1976). Unfertilized oocytes do not contain any ribonucleotide reductase activity; such activity begins to appear shortly after fertilization. In virtually all organisms, this enzyme is composed of two dissimilar subunits with molecular masses of approximately 44 and 88 kD, both of which are required for activity. This paper reports the identification of the large subunit of clam ribonucleotide reductase isolated by dATP-Sepharose chromatography as a relatively abundant 86-kD polypeptide which is already present in oocytes, and whose level remains constant during early development. The enzyme activity of this large subunit was established in reconstitution assays using the small subunit isolated from embryos by virtue of its binding to the anti-tubulin antibody YL 1/2. Thus the two components of clam ribonucleotide reductase are differentially stored in the oocyte: the small subunit in the form of untranslated mRNA and the large subunit as protein. When fertilization triggers the activation of translation of the maternal mRNA, the newly synthesized small subunit combines with the preformed large subunit to generate active ribonucleotide reductase. PMID:3536960

  3. Cell compaction influences the regenerative potential of passaged bovine articular chondrocytes in an ex vivo cartilage defect model.

    PubMed

    Schmutzer, Michael; Aszodi, Attila

    2017-04-01

    The loss and degradation of articular cartilage tissue matrix play central roles in the process of osteoarthritis (OA). New models for evaluating cartilage repair/regeneration are thus of great value for transferring various culture systems into clinically relevant situations. The repair process can be better monitored in ex vivo systems than in in vitro cell cultures. I have therefore established an ex vivo defect model prepared from bovine femoral condyles for evaluating cartilage repair by the implantation of cells cultured in various ways, e.g., monolayer-cultured cells or suspension or pellet cultures of articular bovine chondrocytes representing different cell compactions with variable densities of chondrocytes. I report that the integrin subunit α10 was significantly upregulated in suspension-cultured bovine chondrocytes at passage P2 compared with monolayer-cultured cells at P1 (p = 0.0083) and P2 (p < 0.05). Suspension-cultured cells did not promote cartilage repair when compared with implanted monolayer-cultured chondrocytes and pellets: 24.0 ± 0.66% for suspension cells, 46.4 ± 2.9% for monolayer cells, and 127.64 ± 0.90% for pellets (p < 0.0001) of the original defect volume (percentage of defect). Additional cultivation with chondrogenesis-promoting growth factors TGF-β1 and BMP-2 revealed an enhancing effect on cartilage repair in all settings. The advantage and innovation of this system over in vitro differentiation (e.g., micromass, pellet) assays is the possibility of examining and evaluating cartilage regeneration in an environment in which implanted cells are embedded within native surrounding tissue at the defect site. Such ex vivo explants might serve as a better model system to mimic clinical situations.

  4. Prefoldin Subunits Are Protected from Ubiquitin-Proteasome System-mediated Degradation by Forming Complex with Other Constituent Subunits*

    PubMed Central

    Miyazawa, Makoto; Tashiro, Erika; Kitaura, Hirotake; Maita, Hiroshi; Suto, Hiroo; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    2011-01-01

    The molecular chaperone prefoldin (PFD) is a complex comprised of six different subunits, PFD1-PFD6, and delivers newly synthesized unfolded proteins to cytosolic chaperonin TRiC/CCT to facilitate the folding of proteins. PFD subunits also have functions different from the function of the PFD complex. We previously identified MM-1α/PFD5 as a novel c-Myc-binding protein and found that MM-1α suppresses transformation activity of c-Myc. However, it remains unclear how cells regulate protein levels of individual subunits and what mechanisms alter the ratio of their activities between subunits and their complex. In this study, we found that knockdown of one subunit decreased protein levels of other subunits and that transfection of five subunits other than MM-1α into cells increased the level of endogenous MM-1α. We also found that treatment of cells with MG132, a proteasome inhibitor, increased the level of transfected/overexpressed MM-1α but not that of endogenous MM-1α, indicating that overexpressed MM-1α, but not endogenous MM-1α, was degraded by the ubiquitin proteasome system (UPS). Experiments using other PFD subunits showed that the UPS degraded a monomer of PFD subunits, though extents of degradation varied among subunits. Furthermore, the level of one subunit was increased after co-transfection with the respective subunit, indicating that there are specific combinations between subunits to be stabilized. These results suggest mutual regulation of protein levels among PFD subunits and show how individual subunits form the PFD complex without degradation. PMID:21478150

  5. Prefoldin subunits are protected from ubiquitin-proteasome system-mediated degradation by forming complex with other constituent subunits.

    PubMed

    Miyazawa, Makoto; Tashiro, Erika; Kitaura, Hirotake; Maita, Hiroshi; Suto, Hiroo; Iguchi-Ariga, Sanae M M; Ariga, Hiroyoshi

    2011-06-03

    The molecular chaperone prefoldin (PFD) is a complex comprised of six different subunits, PFD1-PFD6, and delivers newly synthesized unfolded proteins to cytosolic chaperonin TRiC/CCT to facilitate the folding of proteins. PFD subunits also have functions different from the function of the PFD complex. We previously identified MM-1α/PFD5 as a novel c-Myc-binding protein and found that MM-1α suppresses transformation activity of c-Myc. However, it remains unclear how cells regulate protein levels of individual subunits and what mechanisms alter the ratio of their activities between subunits and their complex. In this study, we found that knockdown of one subunit decreased protein levels of other subunits and that transfection of five subunits other than MM-1α into cells increased the level of endogenous MM-1α. We also found that treatment of cells with MG132, a proteasome inhibitor, increased the level of transfected/overexpressed MM-1α but not that of endogenous MM-1α, indicating that overexpressed MM-1α, but not endogenous MM-1α, was degraded by the ubiquitin proteasome system (UPS). Experiments using other PFD subunits showed that the UPS degraded a monomer of PFD subunits, though extents of degradation varied among subunits. Furthermore, the level of one subunit was increased after co-transfection with the respective subunit, indicating that there are specific combinations between subunits to be stabilized. These results suggest mutual regulation of protein levels among PFD subunits and show how individual subunits form the PFD complex without degradation.

  6. Compaction of Space Mission Wastes

    NASA Technical Reports Server (NTRS)

    Fisher, John; Pisharody, Suresh; Wignarajah, K.

    2004-01-01

    The current solid waste management system employed on the International Space Station (ISS) consists of compaction, storage, and disposal. Wastes such plastic food packaging and trash are compacted manually and wrapped in duct tape footballs by the astronauts. Much of the waste is simply loaded either into the empty Russian Progress vehicle for destruction on reentry or into Shuttle for return to Earth. This manual method is wasteful of crew time and does not transition well to far term missions. Different wastes onboard spacecraft vary considerably in their characteristics and in the appropriate method of management. In advanced life support systems for far term missions, recovery of resources such as water from the wastes becomes important. However waste such as plastic food packaging, which constitutes a large fraction of solid waste (roughly 21% on ISS, more on long duration missions), contains minimal recoverable resource. The appropriate management of plastic waste is waste stabilization and volume minimization rather than resource recovery. This paper describes work that has begun at Ames Research Center on development of a heat melt compactor that can be used on near term and future missions, that can minimize crew interaction, and that can handle wastes with a significant plastic composition. The heat melt compactor takes advantage of the low melting point of plastics to compact plastic materials using a combination of heat and pressure. The US Navy has demonstrated successful development of a similar unit for shipboard application. Ames is building upon the basic approach demonstrated by the Navy to develop an advanced heat melt type compactor for space mission type wastes.

  7. Inherent conformational flexibility of F1-ATPase α-subunit.

    PubMed

    Hahn-Herrera, Otto; Salcedo, Guillermo; Barril, Xavier; García-Hernández, Enrique

    2016-09-01

    The core of F1-ATPase consists of three catalytic (β) and three noncatalytic (α) subunits, forming a hexameric ring in alternating positions. A wealth of experimental and theoretical data has provided a detailed picture of the complex role played by catalytic subunits. Although major conformational changes have only been seen in β-subunits, it is clear that α-subunits have to respond to these changes in order to be able to transmit information during the rotary mechanism. However, the conformational behavior of α-subunits has not been explored in detail. Here, we have combined unbiased molecular dynamics (MD) simulations and calorimetrically measured thermodynamic signatures to investigate the conformational flexibility of isolated α-subunits, as a step toward deepening our understanding of its function inside the α3β3 ring. The simulations indicate that the open-to-closed conformational transition of the α-subunit is essentially barrierless, which is ideal to accompany and transmit the movement of the catalytic subunits. Calorimetric measurements of the recombinant α-subunit from Geobacillus kaustophilus indicate that the isolated subunit undergoes no significant conformational changes upon nucleotide binding. Simulations confirm that the nucleotide-free and nucleotide-bound subunits show average conformations similar to that observed in the F1 crystal structure, but they reveal an increased conformational flexibility of the isolated α-subunit upon MgATP binding, which might explain the evolutionary conserved capacity of α-subunits to recognize nucleotides with considerable strength. Furthermore, we elucidate the different dependencies that α- and β-subunits show on Mg(II) for recognizing ATP.

  8. Two Piece Compaction Die Design

    SciTech Connect

    Coffey, Ethan N

    2010-03-01

    Compaction dies used to create europium oxide and tantalum control plates were modeled using ANSYS 11.0. Two-piece designs were considered in order to make the dies easier to assemble than the five-piece dies that were previously used. The two areas of concern were the stresses at the interior corner of the die cavity and the distortion of the cavity wall due to the interference fit between the two pieces and the pressure exerted on the die during the compaction process. A successful die design would have stresses less than the yield stress of the material and a maximum wall distortion on the order of 0.0001 in. Design factors that were investigated include the inner corner radius, the value of the interference fit, the compaction force, the size of the cavity, and the outer radius and geometry of the outer ring. The results show that for the europium oxide die, a 0.01 in. diameter wire can be used to create the cavity, leading to a 0.0055 in. radius corner, if the radial interference fit is 0.003 in. For the tantalum die, the same wire can be used with a radial interference fit of 0.001 in. Also, for the europium oxide die with a 0.003 in. interference fit, it is possible to use a wire with a diameter of 0.006 in. for the wire burning process. Adding a 10% safety factor to the compaction force tends to lead to conservative estimates of the stresses but not for the wall distortion. However, when the 10% safety factor is removed, the wall distortion is not affected enough to discard the design. Finally, regarding the europium oxide die, when the cavity walls are increased by 0.002 in. per side or the outer ring is made to the same geometry as the tantalum die, all the stresses and wall distortions are within the desired range. Thus, the recommendation is to use a 0.006 in. diameter wire and a 0.003 in. interference fit for the europium oxide die and a 0.01 in. diameter wire and a 0.001 in. interference fit for the tantalum die. The dies can also be made to have the

  9. Compact Radiometers Expand Climate Knowledge

    NASA Technical Reports Server (NTRS)

    2010-01-01

    To gain a better understanding of Earth's water, energy, and carbon cycles, NASA plans to embark on the Soil Moisture Active and Passive mission in 2015. To prepare, Goddard Space Flight Center provided Small Business Innovation Research (SBIR) funding to ProSensing Inc., of Amherst, Massachusetts, to develop a compact ultrastable radiometer for sea surface salinity and soil moisture mapping. ProSensing incorporated small, low-cost, high-performance elements into just a few circuit boards and now offers two lightweight radiometers commercially. Government research agencies, university research groups, and large corporations around the world are using the devices for mapping soil moisture, ocean salinity, and wind speed.

  10. Exceptionally bright, compact starburst nucleus

    SciTech Connect

    Margon, B.; Anderson, S.F.; Mateo, M.; Fich, M.; Massey, P.

    1988-11-01

    Observations are reported of a remarkably bright (V about 13) starburst nucleus, 0833 + 652, which has been detected at radio, infrared, optical, ultraviolet, and X-ray wavelengths. Despite an observed flux at each of these wavelengths which is comparable to that of NGC 7714, often considered the 'prototypical' example of the starburst phenomenon, 0833 + 652 appears to be a previously uncataloged object. Its ease of detectability throughout the electromagnetic spectrum should make it useful for a variety of problems in the study of compact emission-line galaxies. 30 references.

  11. Shock compaction of molybdenum powder

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.; Kostka, D.; Vreeland, T., Jr.; Schwarz, R. B.; Kasiraj, P.

    1983-01-01

    Shock recovery experiments which were carried out in the 9 to 12 GPa range on 1.4 distension Mo and appear adequate to compact to full density ( 45 (SIGMA)m) powders were examined. The stress levels, however, are below those calculated to be from 100 to approx. 22 GPa which a frictional heating model predicts are required to consolidate approx. 10 to 50 (SIGMA)m particles. The model predicts that powders that have a distension of m=1.6 shock pressures of 14 to 72 GPa are required to consolidate Mo powders in the 50 to 10 (SIGMA)m range.

  12. Compact inline optical electron polarimeter.

    PubMed

    Pirbhai, M; Ryan, D M; Richards, G; Gay, T J

    2013-05-01

    A compact optical electron polarimeter using a helium target is described. It offers a maximum fluorescence detection efficiency of ~20 Hz/nA, which is an order of magnitude higher than that of earlier designs. With an argon target, this device is expected to have a polarimetric figure-of-merit of 270 Hz/nA. By relying on a magnetic field to guide a longitudinally spin-polarized electron beam, the present instrument employs fewer electrodes. It also uses a commercially available integrated photon counting module. These features allow it to occupy a smaller volume and make it easier to operate.

  13. Comparison of Obturation Quality in Modified Continuous Wave Compaction, Continuous Wave Compaction, Lateral Compaction and Warm Vertical Compaction Techniques

    PubMed Central

    Aminsobhani, Mohsen; Ghorbanzadeh, Abdollah; Sharifian, Mohammad Reza; Namjou, Sara; Kharazifard, Mohamad Javad

    2015-01-01

    Objectives: The aim of this study was to introduce modified continuous wave compaction (MCWC) technique and compare its obturation quality with that of lateral compaction (LC), warm vertical compaction (WVC) and continuous wave compaction techniques (CWC). The obturation time was also compared among the four techniques. Materials and Methods: Sixty-four single-rooted teeth with 0–5° root canal curve and 64 artificially created root canals with 15° curves in acrylic blocks were evaluated. The teeth and acrylic specimens were each divided into four subgroups of 16 for testing the obturation quality of four techniques namely LC, WVC, CWC and MCWC. Canals were prepared using the Mtwo rotary system and filled with respect to their group allocation. Obturation time was recorded. On digital radiographs, the ratio of area of voids to the total area of filled canals was calculated using the Image J software. Adaptation of the filling materials to the canal walls was assessed at three cross-sections under a stereomicroscope (X30). Data were statistically analyzed using ANOVA, Tukey’s post hoc HSD test, the Kruskal Wallis test and t-test. Results: No significant difference existed in adaptation of filling materials to canal walls among the four subgroups in teeth samples (P ≥ 0.139); but, in artificially created canals in acrylic blocks, the frequency of areas not adapted to the canal walls was significantly higher in LC technique compared to MCWC (P ≤ 0.02). The void areas were significantly more in the LC technique than in other techniques in teeth (P < 0.001). The longest obturation time belonged to WVC technique followed by LC, CW and MCWC techniques (P<0.05). The difference between the artificially created canals in blocks and teeth regarding the obturation time was not significant (P = 0.41). Conclusion: Within the limitations of this in vitro study, MCWC technique resulted in better adaptation of gutta-percha to canal walls than LC at all cross-sections with

  14. Conformational changes in the C terminus of Shaker K+ channel bound to the rat Kvβ2-subunit

    PubMed Central

    Sokolova, Olga; Accardi, Alessio; Gutierrez, David; Lau, Adrian; Rigney, Mike; Grigorieff, Nikolaus

    2003-01-01

    We studied the structure of the C terminus of the Shaker potassium channel. The 3D structures of the full-length and a C-terminal deletion (ΔC) mutant of Shaker were determined by electron microscopy and single-particle analysis. The difference map between the full-length and the truncated channels clearly shows a compact density, located on the sides of the T1 domain, that corresponds to a large part of the C terminus. We also expressed and purified both WT and ΔC Shaker, assembled with the rat Kvβ2-subunit. By using a difference map between the full-length and truncated Shaker α–β complexes, a conformational change was identified that shifts a large part of the C terminus away from the membrane domain and into close contact with the β-subunit. This conformational change, induced by the binding of the Kvβ2-subunit, suggests a possible mechanism for the modulation of the K+ voltage-gated channel function by its β-subunit. PMID:14569011

  15. Charge-state dependent compaction and dissociation of protein complexes: insights from ion mobility and molecular dynamics.

    PubMed

    Hall, Zoe; Politis, Argyris; Bush, Matthew F; Smith, Lorna J; Robinson, Carol V

    2012-02-22

    Collapse to compact states in the gas phase, with smaller collision cross sections than calculated for their native-like structure, has been reported previously for some protein complexes although not rationalized. Here we combine experimental and theoretical studies to investigate the gas-phase structures of four multimeric protein complexes during collisional activation. Importantly, using ion mobility-mass spectrometry (IM-MS), we find that all four macromolecular complexes retain their native-like topologies at low energy. Upon increasing the collision energy, two of the four complexes adopt a more compact state. This collapse was most noticeable for pentameric serum amyloid P (SAP) which contains a large central cavity. The extent of collapse was found to be highly correlated with charge state, with the surprising observation that the lowest charge states were those which experience the greatest degree of compaction. We compared these experimental results with in vacuo molecular dynamics (MD) simulations of SAP, during which the temperature was increased. Simulations showed that low charge states of SAP exhibited compact states, corresponding to collapse of the ring, while intermediate and high charge states unfolded to more extended structures, maintaining their ring-like topology, as observed experimentally. To simulate the collision-induced dissociation (CID) of different charge states of SAP, we used MS to measure the charge state of the ejected monomer and assigned this charge to one subunit, distributing the residual charges evenly among the remaining four subunits. Under these conditions, MD simulations captured the unfolding and ejection of a single subunit for intermediate charge states of SAP. The highest charge states recapitulated the ejection of compact monomers and dimers, which we observed in CID experiments of high charge states of SAP, accessed by supercharging. This strong correlation between theory and experiment has implications for further

  16. Phase distribution and microstructural changes of self-compacting cement paste at elevated temperature

    SciTech Connect

    Ye, G. . E-mail: ye.guang@citg.tudelft.nl; Liu, X.; De Schutter, G.; Taerwe, L.; Vandevelde, P.

    2007-06-15

    Self-compacting concrete, as a new smart building material with various advanced properties, has been used for a wide range of structures and infrastructures. However little investigation have been reported on the properties of Self-compacting when it is exposed to elevated temperatures. Previous experiments on fire test have shown the differences between high performance concrete and traditional concrete at elevated temperature. This difference is largely depending on the microstructural properties of concrete matrix, i.e. the cement paste, especially on the porosity, pore size distribution and the connectivity of pores in cement pastes. In this contribution, the investigations are focused on the cement paste. The phase distribution and microstructural changes of self-compacting cement paste at elevated temperatures are examined by mercury intrusion porosimetry and scanning electron microscopy. The chemical decomposition of self-compacting cement paste at different temperatures is determined by thermogravimetric analysis. The experimental results of self-compacting cement paste are compared with those of high performance cement paste and traditional cement paste. It was found that self-compacting cement paste shows a higher change of the total porosity in comparison with high performance cement paste. When the temperature is higher than 700 deg. C, a dramatic loss of mass was observed in the self-compacting cement paste samples with addition of limestone filler. This implies that the SCC made by this type of self-compacting cement paste will probably show larger damage once exposed to fire. Investigation has shown that 0.5 kg/m{sup 3} of Polypropylene fibers in the self-compacting cement paste can avoid the damage efficiently.

  17. [Nose surgical anatomy in six aesthetic subunits].

    PubMed

    Chaput, B; Lauwers, F; Lopez, R; Saboye, J; André, A; Grolleau, J-L; Chavoin, J-P

    2013-04-01

    The nose is a complex entity, combining aesthetic and functional roles. Descriptive anatomy is a fundamental science that it can be difficult to relate directly to our daily surgical activity. Reasoning in terms of aesthetic subunits to decide on his actions appeared to us so obvious. The aim of this paper is to resume the anatomical bases relevant to our daily practice in order to fully apprehend the restorative or cosmetic procedures. We discuss the limits of the systematization of these principles in nasal oncology.

  18. A compact THz imaging system

    NASA Astrophysics Data System (ADS)

    Sešek, Aleksander; Å vigelj, Andrej; Trontelj, Janez

    2015-03-01

    The objective of this paper is the development of a compact low cost imaging THz system, usable for observation of the objects near to the system and also for stand-off detection. The performance of the system remains at the high standard of more expensive and bulkiest system on the market. It is easy to operate as it is not dependent on any fine mechanical adjustments. As it is compact and it consumes low power, also a portable system was developed for stand-off detection of concealed objects under textile or inside packages. These requirements rule out all optical systems like Time Domain Spectroscopy systems which need fine optical component positioning and requires a large amount of time to perform a scan and the image capture pixel-by-pixel. They are also almost not suitable for stand-off detection due to low output power. In the paper the antenna - bolometer sensor microstructure is presented and the THz system described. Analysis and design guidelines for the bolometer itself are discussed. The measurement results for both near and stand-off THz imaging are also presented.

  19. Cold compaction of water ice

    USGS Publications Warehouse

    Durham, W.B.; McKinnon, W.B.; Stern, L.A.

    2005-01-01

    Hydrostatic compaction of granulated water ice was measured in laboratory experiments at temperatures 77 K to 120 K. We performed step-wise hydrostatic pressurization tests on 5 samples to maximum pressures P of 150 MPa, using relatively tight (0.18-0.25 mm) and broad (0.25-2.0 mm) starting grain-size distributions. Compaction change of volume is highly nonlinear in P, typical for brittle, granular materials. No time-dependent creep occurred on the lab time scale. Significant residual porosity (???0.10) remains even at highest P. Examination by scanning electron microscopy (SEM) reveals a random configuration of fractures and broad distribution of grain sizes, again consistent with brittle behavior. Residual porosity appears as smaller, well-supported micropores between ice fragments. Over the interior pressures found in smaller midsize icy satellites and Kuiper Belt objects (KBOs), substantial porosity can be sustained over solar system history in the absence of significant heating and resultant sintering. Copyright 2005 by the American Geophysical Union.

  20. Incompletely compacted equilibrated ordinary chondrites

    SciTech Connect

    Sasso, M.R.; Macke, R.J.; Boesenberg, J.S.; Britt, D.T.; Rovers, M.L.; Ebel, D.S.; Friedrich, J.M.

    2010-01-22

    We document the size distributions and locations of voids present within five highly porous equilibrated ordinary chondrites using high-resolution synchrotron X-ray microtomography ({mu}CT) and helium pycnometry. We found total porosities ranging from {approx}10 to 20% within these chondrites, and with {mu}CT we show that up to 64% of the void space is located within intergranular voids within the rock. Given the low (S1-S2) shock stages of the samples and the large voids between mineral grains, we conclude that these samples experienced unusually low amounts of compaction and shock loading throughout their entire post accretionary history. With Fe metal and FeS metal abundances and grain size distributions, we show that these chondrites formed naturally with greater than average porosities prior to parent body metamorphism. These materials were not 'fluffed' on their parent body by impact-related regolith gardening or events caused by seismic vibrations. Samples of all three chemical types of ordinary chondrites (LL, L, H) are represented in this study and we conclude that incomplete compaction is common within the asteroid belt.

  1. Manufacturability of compact synchrotron mirrors

    NASA Astrophysics Data System (ADS)

    Douglas, Gary M.

    1997-11-01

    While many of the government funded research communities over the years have put their faith and money into increasingly larger synchrotrons, such as Spring8 in Japan, and the APS in the United States, a viable market appears to exist for smaller scale, research and commercial grade, compact synchrotrons. These smaller, and less expensive machines, provide the research and industrial communities with synchrotron radiation beamline access at a portion of the cost of their larger and more powerful counterparts. A compact synchrotron, such as the Aurora-2D, designed and built by Sumitomo Heavy Industries, Ltd. of japan (SHI), is a small footprint synchrotron capable of sustaining 20 beamlines. Coupled with a Microtron injector, with 150 MeV of injection energy, an entire facility fits within a 27 meter [88.5 ft] square floorplan. The system, controlled by 2 personal computers, is capable of producing 700 MeV electron energy and 300 mA stored current. Recently, an Aurora-2D synchrotron was purchased from SHI by the University of Hiroshima. The Rocketdyne Albuquerque Operations Beamline Optics Group was approached by SHI with a request to supply a group of 16 beamline mirrors for this machine. These mirrors were sufficient to supply 3 beamlines for the Hiroshima machine. This paper will address engineering issues which arose during the design and manufacturing of these mirrors.

  2. Compaction with automatic jog introduction

    NASA Astrophysics Data System (ADS)

    Maley, E. M.

    1986-11-01

    This thesis presents an algorithm for one-dimensional compaction of VLSI layouts. It differs from older methods in treating wires not as objects to be moved, but as constraints on the positions of other circuit components. These constraints are determined for each wiring layer using the theory of planar routing. Assuming that the wiring layers can be treated independently, the algorithm minimizes the width of a layout, automatically inserting as many jogs in wires as necessary. It runs in time O(n4) on input of size n. Several heuristics are suggested for improving the algorithm's practical performance. The compaction algorithm takes as input a data structure called a sketch, which explicitly distinguished between flexible components (wires) and rigid components (modules). The algorithms first finds constraints on the positions of modules that ensure enough space is left for wires. Next, it solves the system of constraints by a standard graph-theoretic technique, obtaining a placement for the modules. It then relies on a single-layer router to restore the wires to each circuit layer.

  3. Compacted carbon for electrochemical cells

    DOEpatents

    Greinke, R.A.; Lewis, I.C.

    1997-10-14

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (1) an x-ray density of at least 2.00 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 47%; and (b) graphite having the following properties: (1) an x-ray density of at least 2.20 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counter electrode. 10 figs.

  4. Compacted carbon for electrochemical cells

    DOEpatents

    Greinke, Ronald Alfred; Lewis, Irwin Charles

    1997-01-01

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (i) an x-ray density of at least 2.00 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 47%; and (b) graphite having the following properties: (i) an x-ray density of at least 2.20 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counterelectrode.

  5. Hydrostatic compaction of Microtherm HT.

    SciTech Connect

    Broome, Scott Thomas; Bauer, Stephen J.

    2010-09-01

    Two samples of jacketed Microtherm{reg_sign}HT were hydrostatically pressurized to maximum pressures of 29,000 psi to evaluate both pressure-volume response and change in bulk modulus as a function of density. During testing, each of the two samples exhibited large irreversible compactive volumetric strains with only small increases in pressure; however at volumetric strains of approximately 50%, the Microtherm{reg_sign}HT stiffened noticeably at ever increasing rates. At the maximum pressure of 29,000 psi, the volumetric strains for both samples were approximately 70%. Bulk modulus, as determined from hydrostatic unload/reload loops, increased by more than two-orders of magnitude (from about 4500 psi to over 500,000 psi) from an initial material density of {approx}0.3 g/cc to a final density of {approx}1.1 g/cc. An empirical fit to the density vs. bulk modulus data is K = 492769{rho}{sup 4.6548}, where K is the bulk modulus in psi, and {rho} is the material density in g/cm{sup 3}. The porosity decreased from 88% to {approx}20% indicating that much higher pressures would be required to compact the material fully.

  6. Compact Microscope Imaging System Developed

    NASA Technical Reports Server (NTRS)

    McDowell, Mark

    2001-01-01

    The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was developed at the NASA Glenn Research Center, can scan, find areas of interest, focus, and acquire images automatically. Large numbers of multiple cell experiments require microscopy for in situ observations; this is only feasible with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control capabilities. The software also has a user-friendly interface that can be used independently of the hardware for post-experiment analysis. CMIS has potential commercial uses in the automated online inspection of precision parts, medical imaging, security industry (examination of currency in automated teller machines and fingerprint identification in secure entry locks), environmental industry (automated examination of soil/water samples), biomedical field (automated blood/cell analysis), and microscopy community. CMIS will improve research in several ways: It will expand the capabilities of MSD experiments utilizing microscope technology. It may be used in lunar and Martian experiments (Rover Robot). Because of its reduced size, it will enable experiments that were not feasible previously. It may be incorporated into existing shuttle orbiter and space station experiments, including glove-box-sized experiments as well as ground-based experiments.

  7. Amino-terminal truncations of the ribulose-bisphosphate carboxylase small subunit influence catalysis and subunit interactions.

    PubMed Central

    Paul, K; Morell, M K; Andrews, T J

    1993-01-01

    The first 20 residues at the amino terminus of the small subunit of spinach ribulose-1,5-bisphosphate carboxylase form an irregular arm that makes extensive contacts with the large subunit and also with another small subunit (S. Knight, I. Andersson, and C.-I. Brändén [1990] J Mol Biol 215: 113-160). The influence of these contacts on subunit binding and, indirectly, on catalysis was investigated by constructing truncations from the amino terminus of the small subunit of the highly homologous enzyme from Synechococcus PCC 6301 expressed in Escherichia coli. Removal of the first six residues (and thus the region of contact with a neighboring small subunit) affected neither the affinity with which the small subunits bound to the large subunits nor the catalytic properties of the assembled holoenzyme. Extending the truncation to include the first 12 residues (which encroaches into a highly conserved region that interacts with the large subunit) also did not weaken intersubunit binding appreciably, but it reduced the catalytic activity of the holoenzyme nearly 5-fold. Removal of an additional single residue (i.e. removal of a total of 13 residues) weakened intersubunit binding approximately 80-fold. Paradoxically, this partially restored catalytic activity to approximately 40% of that of the wild-type holoenzyme. None of these truncations materially affected the Km values for ribulose-1,5-bisphosphate or CO2. Removal of all 20 residues of the irregular arm (thereby deleting the conserved region of contact with large subunits) totally abolished the small subunit's ability to bind to large subunits to form a stable holoenzyme. However, this truncated small subunit was still synthesized by the E. coli cells. These data are interpreted in terms of the role of the amino-terminal arm of the small subunit in maintaining the structure of the holoenzyme. PMID:8278544

  8. Dense and Homogeneous Compaction of Fine Ceramic and Metallic Powders: High-Speed Centrifugal Compaction Process

    SciTech Connect

    Suzuki, Hiroyuki Y.

    2008-02-15

    High-Speed Centrifugal Compaction Process (HCP) is a variation of colloidal compacting method, in which the powders sediment under huge centrifugal force. Compacting mechanism of HCP differs from conventional colloidal process such as slip casting. The unique compacting mechanism of HCP leads to a number of characteristics such as a higher compacting speed, wide applicability for net shape formation, flawless microstructure of the green compacts, etc. However, HCP also has several deteriorative characteristics that must be overcome to fully realize this process' full potential.

  9. Brittle and compaction creep in porous sandstone

    NASA Astrophysics Data System (ADS)

    Heap, Michael; Brantut, Nicolas; Baud, Patrick; Meredith, Philip

    2015-04-01

    Strain localisation in the Earth's crust occurs at all scales, from the fracture of grains at the microscale to crustal-scale faulting. Over the last fifty years, laboratory rock deformation studies have exposed the variety of deformation mechanisms and failure modes of rock. Broadly speaking, rock failure can be described as either dilatant (brittle) or compactive. While dilatant failure in porous sandstones is manifest as shear fracturing, their failure in the compactant regime can be characterised by either distributed cataclastic flow or the formation of localised compaction bands. To better understand the time-dependency of strain localisation (shear fracturing and compaction band growth), we performed triaxial deformation experiments on water-saturated Bleurswiller sandstone (porosity = 24%) under a constant stress (creep) in the dilatant and compactive regimes, with particular focus on time-dependent compaction band formation in the compactive regime. Our experiments show that inelastic strain accumulates at a constant stress in the brittle and compactive regimes leading to the development of shear fractures and compaction bands, respectively. While creep in the dilatant regime is characterised by an increase in porosity and, ultimately, an acceleration in axial strain to shear failure (as observed in previous studies), compaction creep is characterised by a reduction in porosity and a gradual deceleration in axial strain. The overall deceleration in axial strain, AE activity, and porosity change during creep compaction is punctuated by excursions interpreted as the formation of compaction bands. The growth rate of compaction bands formed during creep is lower as the applied differential stress, and hence background creep strain rate, is decreased, although the inelastic strain required for a compaction band remains constant over strain rates spanning several orders of magnitude. We find that, despite the large differences in strain rate and growth rate

  10. Organization of Subunits in the Membrane Domain of the Bovine F-ATPase Revealed by Covalent Cross-linking*

    PubMed Central

    Lee, Jennifer; Ding, ShuJing; Walpole, Thomas B.; Holding, Andrew N.; Montgomery, Martin G.; Fearnley, Ian M.; Walker, John E.

    2015-01-01

    The F-ATPase in bovine mitochondria is a membrane-bound complex of about 30 subunits of 18 different kinds. Currently, ∼85% of its structure is known. The enzyme has a membrane extrinsic catalytic domain, and a membrane intrinsic domain where the turning of the enzyme's rotor is generated from the transmembrane proton-motive force. The domains are linked by central and peripheral stalks. The central stalk and a hydrophobic ring of c-subunits in the membrane domain constitute the enzyme's rotor. The external surface of the catalytic domain and membrane subunit a are linked by the peripheral stalk, holding them static relative to the rotor. The membrane domain contains six additional subunits named ATP8, e, f, g, DAPIT (diabetes-associated protein in insulin-sensitive tissues), and 6.8PL (6.8-kDa proteolipid), each with a single predicted transmembrane α-helix, but their orientation and topography are unknown. Mutations in ATP8 uncouple the enzyme and interfere with its assembly, but its roles and the roles of the other five subunits are largely unknown. We have reacted accessible amino groups in the enzyme with bifunctional cross-linking agents and identified the linked residues. Cross-links involving the supernumerary subunits, where the structures are not known, show that the C terminus of ATP8 extends ∼70 Å from the membrane into the peripheral stalk and that the N termini of the other supernumerary subunits are on the same side of the membrane, probably in the mitochondrial matrix. These experiments contribute significantly toward building up a complete structural picture of the F-ATPase. PMID:25851905

  11. β-Subunit Binding Is Sufficient for Ligands to Open the Integrin αIIbβ3 Headpiece.

    PubMed

    Lin, Fu-Yang; Zhu, Jianghai; Eng, Edward T; Hudson, Nathan E; Springer, Timothy A

    2016-02-26

    The platelet integrin αIIbβ3 binds to a KQAGDV motif at the fibrinogen γ-chain C terminus and to RGD motifs present in loops in many extracellular matrix proteins. These ligands bind in a groove between the integrin α and β-subunits; the basic Lys or Arg side chain hydrogen bonds to the αIIb-subunit, and the acidic Asp side chain coordinates to a metal ion held by the β3-subunit. Ligand binding induces headpiece opening, with conformational change in the β-subunit. During this opening, RGD slides in the ligand-binding pocket toward αIIb, with movement of the βI-domain β1-α1 loop toward αIIb, enabling formation of direct, charged hydrogen bonds between the Arg side chain and αIIb. Here we test whether ligand interactions with β3 suffice for stable ligand binding and headpiece opening. We find that the AGDV tetrapeptide from KQAGDV binds to the αIIbβ3 headpiece with affinity comparable with the RGDSP peptide from fibronectin. AGDV induced complete headpiece opening in solution as shown by increase in hydrodynamic radius. Soaking of AGDV into closed αIIbβ3 headpiece crystals induced intermediate states similarly to RGDSP. AGDV has very little contact with the α-subunit. Furthermore, as measured by epitope exposure, AGDV, like the fibrinogen γ C-terminal peptide and RGD, caused integrin extension on the cell surface. Thus, pushing by the β3-subunit on Asp is sufficient for headpiece opening and ligand sliding, and no pulling by the αIIb subunit on Arg is required.

  12. Compact Solid State Cooling Systems: Compact MEMS Electrocaloric Module

    SciTech Connect

    2010-10-01

    BEETIT Project: UCLA is developing a novel solid-state cooling technology to translate a recent scientific discovery of the so-called giant electrocaloric effect into commercially viable compact cooling systems. Traditional air conditioners use noisy, vapor compression systems that include a polluting liquid refrigerant to circulate within the air conditioner, absorb heat, and pump the heat out into the environment. Electrocaloric materials achieve the same result by heating up when placed within an electric field and cooling down when removed—effectively pumping heat out from a cooler to warmer environment. This electrocaloric-based solid state cooling system is quiet and does not use liquid refrigerants. The innovation includes developing nano-structured materials and reliable interfaces for heat exchange. With these innovations and advances in micro/nano-scale manufacturing technologies pioneered by semiconductor companies, UCLA is aiming to extend the performance/reliability of the cooling module.

  13. Algebraic construction of the Darboux matrix revisited

    NASA Astrophysics Data System (ADS)

    Cieśliński, Jan L.

    2009-10-01

    We present algebraic construction of Darboux matrices for 1+1-dimensional integrable systems of nonlinear partial differential equations with a special stress on the nonisospectral case. We discuss different approaches to the Darboux-Bäcklund transformation, based on different λ-dependences of the Darboux matrix: polynomial, sum of partial fractions or the transfer matrix form. We derive symmetric N-soliton formulae in the general case. The matrix spectral parameter and dressing actions in loop groups are also discussed. We describe reductions to twisted loop groups, unitary reductions, the matrix Lax pair for the KdV equation and reductions of chiral models (harmonic maps) to SU(n) and to Grassmann spaces. We show that in the KdV case the nilpotent Darboux matrix generates the binary Darboux transformation. The paper is intended as a review of known results (usually presented in a novel context) but some new results are included as well, e.g., general compact formulae for N-soliton surfaces and linear and bilinear constraints on the nonisospectral Lax pair matrices which are preserved by Darboux transformations.

  14. Quantitative Homogeneity and In-Contact Particles of High Temperature Reactors (htr) Compacts Determination via X-Ray Tomography

    NASA Astrophysics Data System (ADS)

    Lecomte, G.; Tisseur, D.; Létang, J. M.; Banchet, J.; Vitali, M. P.

    2008-02-01

    In AREVA Nuclear Power's High Temperature Reactor (HTR) design called ANTARES, fuel consists of compacts composed of few thousands millimetric quasi-spherical particles dispersed in a graphite matrix. Compact homogeneity, defined as the homogeneous particles spatial distribution in the matrix, as well as the possibility of obtaining particles in contact, need to be assessed since they condition the thermo-mechanical behavior of the nuclear fuel under irradiation. In this paper, image and data processing algorithms are developed to do so, based on X-Ray tomographic images.

  15. Rapid Sintering of Nano-Diamond Compacts

    SciTech Connect

    Osipov, A.; Nauyoks, S; Zerda, T; Zaporozhets, O

    2009-01-01

    Diamond compacts were sintered from nano-size diamond crystals at high pressure, 8 GPa, and temperature above 1500 degrees C for very short times ranging from 5 to 11 s. Structure and mechanical properties of the compacts have been characterized. Although we have not completely avoided graphitization of diamonds, the amount of graphite produced was low, less than 2%, and despite relatively high porosity, the compacts were characterized by high hardness, bulk and Young moduli.

  16. Carbonate fuel cell matrix

    DOEpatents

    Farooque, Mohammad; Yuh, Chao-Yi

    1996-01-01

    A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

  17. Observations on infiltration of silicon carbide compacts with an aluminium alloy

    NASA Technical Reports Server (NTRS)

    Asthana, R.; Rohatgi, P. K.

    1992-01-01

    The melt infiltration of ceramic particulates permits an opportunity to observe such fundamental materials phenomena as nucleation, dynamic wetting and growth in constrained environments. Experimental observations are presented on the infiltration behavior and matrix microstructures that form when porous compacts of platelet-shaped single crystals of alpha- (hexagonal) silicon carbide are infiltrated with a liquid 2014 Al alloy. The infiltration process involved counter gravity infiltration of suitably tamped and preheated compacts of silicon carbide platelets under an external pressure in a special pressure chamber for a set period, then by solidification of the infiltrant metal in the interstices of the bed at atmospheric pressure.

  18. Matrix with Prescribed Eigenvectors

    ERIC Educational Resources Information Center

    Ahmad, Faiz

    2011-01-01

    It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…

  19. The intraclass covariance matrix.

    PubMed

    Carey, Gregory

    2005-09-01

    Introduced by C.R. Rao in 1945, the intraclass covariance matrix has seen little use in behavioral genetic research, despite the fact that it was developed to deal with family data. Here, I reintroduce this matrix, and outline its estimation and basic properties for data sets on pairs of relatives. The intraclass covariance matrix is appropriate whenever the research design or mathematical model treats the ordering of the members of a pair as random. Because the matrix has only one estimate of a population variance and covariance, both the observed matrix and the residual matrix from a fitted model are easy to inspect visually; there is no need to mentally average homologous statistics. Fitting a model to the intraclass matrix also gives the same log likelihood, likelihood-ratio (LR) chi2, and parameter estimates as fitting that model to the raw data. A major advantage of the intraclass matrix is that only two factors influence the LR chi2--the sampling error in estimating population parameters and the discrepancy between the model and the observed statistics. The more frequently used interclass covariance matrix adds a third factor to the chi2--sampling error of homologous statistics. Because of this, the degrees of freedom for fitting models to an intraclass matrix differ from fitting that model to an interclass matrix. Future research is needed to establish differences in power-if any--between the interclass and the intraclass matrix.

  20. Complementation of subunits from different bacterial luciferases. Evidence for the role of the. beta. subunit in the bioluminescent mechanism

    SciTech Connect

    Meighen, E.A.; Bartlet, I.

    1980-12-10

    Complementation of the nonidentical subunits (..cap alpha.. and ..beta..) of luciferases isolated from two different bioluminescent strains, Beneckea harveyi and Photobacterium phosphoreum, has resulted in the formation of a functional hybrid luciferase (..cap alpha../sub h/..beta../sub p/) containing the ..cap alpha.. subunit from B. harveyi luciferase (..cap alpha../sub h/) and the ..beta.. subunit from P. phosphoreum luciferase (..beta../sub p/). The complementation was unidirectional; activity could not be restored by complementing the ..cap alpha.. subunit of P. phosphoreum luciferase with the ..beta.. subunit of B. harveyi luciferase, showing that the subunits from these luciferases were not identical. Kinetic parameters of the hybrid luciferase reflecting the intermediate and later steps of the bioluminescent reaction as well as the overall activity and specificity were essentially identical to the same kinetic parameters for B. harveyi luciferase, the source of the ..cap alpha.. subunit, and quite distinct from those of P. phosphoreum luciferase. However, kinetic parameters that reflected the initial step in the reaction involving interaction of FMNH/sub 2/ and luciferase were altered in the hybrid luciferase compared to both the parental luciferases, the K/sub d/ for FMNH/sub 2/ actually being closer to that observed for the P. phosphoreum luciferase (the source of the ..beta.. subunit). These results provide direct evidence that modification or alteration of the ..beta.. subunit in a dimeric luciferase molecule can affect the kinetic properties and indicates that the ..beta.. subunit plays a functional role in the bioluminescent mechanism. It is proposed that both the ..cap alpha.. and ..beta.. subunits are involved with the initial interaction with FMNH/sub 2/, whereas subsequent steps in the mechanism are dictated exclusively by the ..cap alpha.. subunit and are unaffected by alterations in the ..beta.. subunit.

  1. Formation of active bacterial luciferase between interspecific subunits in vivo.

    PubMed

    Almashanu, S; Tuby, A; Hadar, R; Einy, R; Kuhn, J

    1995-01-01

    Interspecific complementation between luxAs and luxBs from Vibrio harveyi, Vibrio fischeri, Photobacterium leiognathi and Xenorhabdus luminescens was examined in vivo. The individual genes from these species were cloned on different compatible plasmids or amplified by PCR and brought together to yield cis combinations without extraneous DNA. The beta subunits from V. harveyi and X. luminescens form active enzyme only with alpha subunits from one of these species. All other combinations yield active enzymes. The lack of activity of the V. harveyi and X. luminescens beta subunits with the alpha subunits from V. fischeri and P. leiognathi results from a lack of association. This was shown by in vivo competition in which these beta subunits were overproduced in comparison with the beta and alpha of V. fischeri. No reduction in light was found. Overall, the in vivo results parallel those found in vitro using isolated denatured subunits and renaturation by removal of the denaturant.

  2. Sodium channel β subunits: emerging targets in channelopathies

    PubMed Central

    O’Malley, Heather A.; Isom, Lori L.

    2016-01-01

    Voltage-gated sodium channels (VGSCs) are responsible for initiation and propagation of action potentials in excitable cells. VGSCs in mammalian brain are heterotrimeric complexes of α and β subunits. Originally called “auxiliary,” we now know that β subunit proteins are multifunctional signaling molecules that play roles in both excitable and non-excitable cell types, and with or without the pore-forming α subunit present. β subunits function in VGSC and potassium channel modulation, cell adhesion, and gene regulation, with particularly important roles in brain development. Mutations in the genes encoding β subunits are linked to a number of diseases, including epilepsy, sudden death syndromes like SUDEP and SIDS, and cardiac arrhythmia. While VGSC β subunit-specific drugs have not yet been developed, this protein family is an emerging therapeutic target. PMID:25668026

  3. Compact high-voltage structures

    SciTech Connect

    Wilson, M. J.; Goerz, D.A.

    1997-06-09

    A basic understanding of the critical issues limiting the compactness of high-voltage systems is required for the next generation of impulse generators. In the process of optimizing the design of a highly reliable solid-dielectric over-voltage switch, an understanding of the limiting factors found are shown. Results of a l3O kV operating switch, having a modest field enhancement of 16% above the average field stress in the switching region, are reported. The resulting high reliability is obtained by reducing the standard deviation of the switch to 6.8%. The total height of the switch is 1 mm. The resulting operating parameters are obtained by controlling field distribution across the entire switch package and field shaping the desired point of switch closure. The disclosed field management technique provides an approach to improve other highly stressed components and structures.

  4. Compact Microwave Fourier Spectrum Analyzer

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  5. Saloplastics: processing compact polyelectrolyte complexes.

    PubMed

    Schaaf, Pierre; Schlenoff, Joseph B

    2015-04-17

    Polyelectrolyte complexes (PECs) are prepared by mixing solutions of oppositely charged polyelectrolytes. These diffuse, amorphous precipitates may be compacted into dense materials, CoPECs, by ultracentrifugation (ucPECs) or extrusion (exPECs). The presence of salt water is essential in plasticizing PECs to allow them to be reformed and fused. When hydrated, CoPECs are versatile, rugged, biocompatible, elastic materials with applications including bioinspired materials, supports for enzymes and (nano)composites. In this review, various methods for making CoPECs are described, as well as fundamental responses of CoPEC mechanical properties to salt concentration. Possible applications as synthetic cartilage, enzymatically active biocomposites, self-healing materials, and magnetic nanocomposites are presented.

  6. Compact anti-radon facility

    SciTech Connect

    Fajt, L.; Kouba, P.; Mamedov, F.; Smolek, K.; Štekl, I.

    2015-08-17

    Suppression of radon background is one of main tasks in ultra-low background experiments. The most promising technique for suppression of radon is its adsorption on charcoal. Within the frame of the NEMO-3 experiment, radon trapping facility (RTF) was installed in Modane underground laboratory in 2004. Based on long-term experience with this facility a new compact transportable anti-radon facility was constructed in cooperation among IEAP CTU, SÚRO and ATEKO company. The device provides 20m{sup 3}/h of purified air (air radon activity at the output ∼10mBq/m{sup 3}). The basic features and preliminary results of anti-radon device testing are presented.

  7. Experimental studies of compact toroids

    SciTech Connect

    Not Available

    1991-01-01

    The Berkeley Compact Toroid Experiment (BCTX) device is a plasma device with a Marshall-gun generated, low aspect ratio toroidal plasma. The device is capable of producing spheromak-type discharges and may, with some modification, produce low-aspect ratio tokamak configurations. A unique aspect of this experimenal devie is its large lower hybrid (LH) heating system, which consists of two 450MHz klystron tubes generating 20 megawatts each into a brambilla-type launching structure. Successful operation with one klystron at virtually full power (18 MW) has been accomplished with 110 {mu}s pulse length. A second klystron is currently installed in its socket and magnet but has not been added to the RF drive system. This report describes current activities and accomplishments and describes the anticipated results of next year's activity.

  8. Gravitational waves from compact objects

    NASA Astrophysics Data System (ADS)

    de Freitas Pacheco, José Antonio

    2010-11-01

    Large ground-based laser beam interferometers are presently in operation both in the USA (LIGO) and in Europe (VIRGO) and potential sources that might be detected by these instruments are revisited. The present generation of detectors does not have a sensitivity high enough to probe a significant volume of the universe and, consequently, predicted event rates are very low. The planned advanced generation of interferometers will probably be able to detect, for the first time, a gravitational signal. Advanced LIGO and EGO instruments are expected to detect few (some): binary coalescences consisting of either two neutron stars, two black holes or a neutron star and a black hole. In space, the sensitivity of the planned LISA spacecraft constellation will allow the detection of the gravitational signals, even within a “pessimistic" range of possible signals, produced during the capture of compact objects by supermassive black holes, at a rate of a few tens per year.

  9. Compact oleic acid in HAMLET.

    PubMed

    Fast, Jonas; Mossberg, Ann-Kristin; Nilsson, Hanna; Svanborg, Catharina; Akke, Mikael; Linse, Sara

    2005-11-07

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.

  10. Hidden secrets of deformation: Impact-induced compaction within a CV chondrite

    NASA Astrophysics Data System (ADS)

    Forman, L. V.; Bland, P. A.; Timms, N. E.; Collins, G. S.; Davison, T. M.; Ciesla, F. J.; Benedix, G. K.; Daly, L.; Trimby, P. W.; Yang, L.; Ringer, S. P.

    2016-10-01

    The CV3 Allende is one of the most extensively studied meteorites in worldwide collections. It is currently classified as S1-essentially unshocked-using the classification scheme of Stöffler et al. (1991), however recent modelling suggests the low porosity observed in Allende indicates the body should have undergone compaction-related deformation. In this study, we detail previously undetected evidence of impact through use of Electron Backscatter Diffraction mapping to identify deformation microstructures in chondrules, AOAs and matrix grains. Our results demonstrate that forsterite-rich chondrules commonly preserve crystal-plastic microstructures (particularly at their margins); that low-angle boundaries in deformed matrix grains of olivine have a preferred orientation; and that disparities in deformation occur between chondrules, surrounding and non-adjacent matrix grains. We find heterogeneous compaction effects present throughout the matrix, consistent with a highly porous initial material. Given the spatial distribution of these crystal-plastic deformation microstructures, we suggest that this is evidence that Allende has undergone impact-induced compaction from an initially heterogeneous and porous parent body. We suggest that current shock classifications (Stöffler et al., 1991) relying upon data from chondrule interiors do not constrain the complete shock history of a sample.

  11. Physics of Compact Advanced Stellarators

    SciTech Connect

    M.C. Zarnstorff; L.A. Berry; A. Brooks; E. Fredrickson; G.-Y. Fu; S. Hirshman; S. Hudson; L.-P. Ku; E. Lazarus; D. Mikkelsen; D. Monticello; G.H. Neilson; N. Pomphrey; A. Reiman; D. Spong; D. Strickler; A. Boozer; W.A. Cooper; R. Goldston; R. Hatcher; M. Isaev; C. Kessel; J. Lewandowski; J. Lyon; P. Merkel; H. Mynick; B.E. Nelson; C. Nuehrenberg; M. Redi; W. Reiersen; P. Rutherford; R. Sanchez; J. Schmidt; R.B. White

    2001-08-14

    Compact optimized stellarators offer novel solutions for confining high-beta plasmas and developing magnetic confinement fusion. The 3-D plasma shape can be designed to enhance the MHD stability without feedback or nearby conducting structures and provide drift-orbit confinement similar to tokamaks. These configurations offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio 4-4.4 and average elongation of approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for beta > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at beta = 4% (the rest is from the coils), thus the equilibrium is much less nonlinear and is more controllable than similar advanced tokamaks. The enhanced stability is a result of ''reversed'' global shear, the spatial distribution of local shear, and the large fraction of externally generated transform. Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties.

  12. General Relativity&Compact Stars

    SciTech Connect

    Glendenning, Norman K.

    2005-08-16

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10{sup 14} times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed.

  13. Quantifying the cooperative subunit action in a multimeric membrane receptor

    PubMed Central

    Wongsamitkul, Nisa; Nache, Vasilica; Eick, Thomas; Hummert, Sabine; Schulz, Eckhard; Schmauder, Ralf; Schirmeyer, Jana; Zimmer, Thomas; Benndorf, Klaus

    2016-01-01

    In multimeric membrane receptors the cooperative action of the subunits prevents exact knowledge about the operation and the interaction of the individual subunits. We propose a method that permits quantification of ligand binding to and activation effects of the individual binding sites in a multimeric membrane receptor. The power of this method is demonstrated by gaining detailed insight into the subunit action in olfactory cyclic nucleotide-gated CNGA2 ion channels. PMID:26858151

  14. The Integrin β1 Subunit Regulates Paracellular Permeability of Kidney Proximal Tubule Cells*

    PubMed Central

    Elias, Bertha C.; Mathew, Sijo; Srichai, Manakan B.; Palamuttam, Riya; Bulus, Nada; Mernaugh, Glenda; Singh, Amar B.; Sanders, Charles R.; Harris, Raymond C.; Pozzi, Ambra; Zent, Roy

    2014-01-01

    Epithelial cells lining the gastrointestinal tract and kidney have different abilities to facilitate paracellular and transcellular transport of water and solutes. In the kidney, the proximal tubule allows both transcellular and paracellular transport, while the collecting duct primarily facilitates transcellular transport. The claudins and E-cadherin are major structural and functional components regulating paracellular transport. In this study we present the novel finding that the transmembrane matrix receptors, integrins, play a role in regulating paracellular transport of renal proximal tubule cells. Deleting the integrin β1 subunit in these cells converts them from a “loose” epithelium, characterized by low expression of E-cadherin and claudin-7 and high expression of claudin-2, to a “tight” epithelium with increased E-cadherin and claudin-7 expression and decreased claudin-2 expression. This effect is mediated by the integrin β1 cytoplasmic tail and does not entail β1 heterodimerization with an α-subunit or its localization to the cell surface. In addition, we demonstrate that deleting the β1 subunit in the proximal tubule of the kidney results in a major urine-concentrating defect. Thus, the integrin β1 tail plays a key role in regulating the composition and function of tight and adherens junctions that define paracellular transport properties of terminally differentiated renal proximal tubule epithelial cells. PMID:24509849

  15. Lung-specific loss of the laminin α3 subunit confers resistance to mechanical injury.

    PubMed

    Urich, Daniela; Eisenberg, Jessica L; Hamill, Kevin J; Takawira, Desire; Chiarella, Sergio E; Soberanes, Saul; Gonzalez, Angel; Koentgen, Frank; Manghi, Tomas; Hopkinson, Susan B; Misharin, Alexander V; Perlman, Harris; Mutlu, Gokhan M; Budinger, G R Scott; Jones, Jonathan C R

    2011-09-01

    Laminins are heterotrimeric glycoproteins of the extracellular matrix that are secreted by epithelial cells and which are crucial for the normal structure and function of the basement membrane. We have generated a mouse harboring a conditional knockout of α3 laminin (Lama3(fl/fl)), one of the main laminin subunits in the lung basement membrane. At 60 days after intratracheal treatment of adult Lama3(fl/fl) mice with an adenovirus encoding Cre recombinase (Ad-Cre), the protein abundance of α3 laminin in whole lung homogenates was more than 50% lower than that in control-treated mice, suggesting a relatively long half-life for the protein in the lung. Upon exposure to an injurious ventilation strategy (tidal volume of 35 ml per kg of body weight for 2 hours), the mice with a knockdown of the α3 laminin subunit had less severe injury, as shown by lung mechanics, histology, alveolar capillary permeability and survival when compared with Ad-Null-treated mice. Knockdown of the α3 laminin subunit resulted in evidence of lung inflammation. However, this did not account for their resistance to mechanical ventilation. Rather, the loss of α3 laminin was associated with a significant increase in the collagen content of the lungs. We conclude that the loss of α3 laminin in the alveolar epithelium results in an increase in lung collagen, which confers resistance to mechanical injury.

  16. Redefining the roles of mitochondrial DNA-encoded subunits in respiratory Complex I assembly

    PubMed Central

    Vartak, Rasika; Deng, Janice; Fang, Hezhi; Bai, Yidong

    2015-01-01

    Respiratory Complex I deficiency is implicated in numerous degenerative and metabolic diseases. In particular, mutations in several mitochondrial DNA (mtDNA)-encoded Complex I subunits including ND4, ND5 and ND6 have been identified in several neurological diseases. We previously demonstrated that these subunits played essential roles in Complex I assembly which in turn affected mitochondrial function. Here, we carried out a comprehensive study of the Complex I assembly pathway. We identified a new Complex I intermediate containing both membrane and matrix arms at an early assembly stage. We find that lack of the ND6 subunit does not hinder membrane arm formation; instead it recruits ND1 and ND5 enter the intermediate. While ND4 is important for the formation of the newly identified intermediate, the addition of ND5 stabilizes the complex and is required for the critical transition from Complex I to supercomplexes assembly. As a result, the Complex I assembly pathway has been redefined in this study. PMID:25887158

  17. Crosstalk between primase subunits can act to regulate primersynthesis in trans

    SciTech Connect

    Corn, Jacob E.; Pease, Paul J.; Hura, Greg L.; Berger, James M.

    2005-08-12

    The coordination of primase function within the replisome is an essential but poorly understood feature of lagging strand synthesis. By using crystallography and small-angle X-ray scattering (SAXS), we show that functional elements of bacterial primase transition between two dominant conformations: an extended form that uncouples a regulatory domain from its associated RNA polymerase core and a compact state that sequesters the regulatory region from the site of primer synthesis. FRET studies and priming assays reveal that the regulatory domain of one primase subunit productively associates with nucleic acid that is bound to the polymerase domain of a second protomer in trans. This intersubunit interaction allows primase to select initiation sites on template DNA and implicates the regulatory domain as a 'molecular brake' that restricts primer length. Our data suggest that the replisome may cooperatively use multiple primases and this conformational switch to control initiation frequency, processivity, and ultimately, Okazaki fragment synthesis.

  18. 77 FR 20051 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr. Gary S. Barron at (304) 625-2803... CONTACT: Inquiries may be addressed to Mr. Gary S. Barron, FBI Compact Officer, Module D3, 1000 Custer...: March 27, 2012. Gary S. Barron, FBI Compact Officer, Criminal Justice Information Services...

  19. Genetic analysis of neuronal ionotropic glutamate receptor subunits.

    PubMed

    Granger, Adam J; Gray, John A; Lu, Wei; Nicoll, Roger A

    2011-09-01

    In the brain, fast, excitatory synaptic transmission occurs primarily through AMPA- and NMDA-type ionotropic glutamate receptors. These receptors are composed of subunit proteins that determine their biophysical properties and trafficking behaviour. Therefore, determining the function of these subunits and receptor subunit composition is essential for understanding the physiological properties of synaptic transmission. Here, we discuss and evaluate various genetic approaches that have been used to study AMPA and NMDA receptor subunits. These approaches have demonstrated that the GluA1 AMPA receptor subunit is required for activity-dependent trafficking and contributes to basal synaptic transmission, while the GluA2 subunit regulates Ca(2+) permeability, homeostasis and trafficking to the synapse under basal conditions. In contrast, the GluN2A and GluN2B NMDA receptor subunits regulate synaptic AMPA receptor content, both during synaptic development and plasticity. Ongoing research in this field is focusing on the molecular interactions and mechanisms that control these functions. To accomplish this, molecular replacement techniques are being used, where native subunits are replaced with receptors containing targeted mutations. In this review, we discuss a single-cell molecular replacement approach which should arguably advance our physiological understanding of ionotropic glutamate receptor subunits, but is generally applicable to study of any neuronal protein.

  20. Expression of GABA receptor rho subunits in rat brain.

    PubMed

    Boue-Grabot, E; Roudbaraki, M; Bascles, L; Tramu, G; Bloch, B; Garret, M

    1998-03-01

    The GABA receptor rho1, rho2, and rho3 subunits are expressed in the retina where they form bicuculline-insensitive GABA(C) receptors. We used northern blot, in situ hybridization, and RT-PCR analysis to study the expression of rho subunits in rat brains. In situ hybridization allowed us to detect rho-subunit expression in the superficial gray layer of the superior colliculus and in the cerebellar Purkinje cells. RT-PCR experiments indicated that (a) in retina and in domains that may contain functional GABA(C) receptors, rho2 and rho1 subunits are expressed at similar levels; and (b) in domains and in tissues that are unlikely to contain GABA(C) receptors, rho2 mRNA is enriched relative to rho1 mRNA. These results suggest that both rho1 and rho2 subunits are necessary to form a functional GABA(C) receptor. The use of RT-PCR also showed that, except in the superior colliculus, rho3 is expressed along with rho1 and rho2 subunits. We also raised an antibody against a peptide sequence unique to the rho1 subunit. The use of this antibody on cerebellum revealed the rat rho1 subunit in the soma and dendrites of Purkinje neurons. The allocation of GABA(C) receptor subunits to identified neurons paves the way for future electrophysiological studies.

  1. Nanocrystal doped matrixes

    DOEpatents

    Parce, J. Wallace; Bernatis, Paul; Dubrow, Robert; Freeman, William P.; Gamoras, Joel; Kan, Shihai; Meisel, Andreas; Qian, Baixin; Whiteford, Jeffery A.; Ziebarth, Jonathan

    2010-01-12

    Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and/or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

  2. AGR-1 Fuel Compact 6-3-2 Post-Irradiation Examination Results

    SciTech Connect

    Paul demkowicz; jason Harp; Scott Ploger

    2012-12-01

    Destructive post-irradiation examination was performed on fuel Compact 6-3-2, which was irradiated in the AGR-1 experiment to a final compact average burnup of 11.3% FIMA and a time-average, volume-average temperature of 1070°C. The analysis of this compact was focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, measurement of fuel burnup by several methods, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy. A single particle with a defective SiC layer was identified during deconsolidation-leach-burn-leach analysis, which is in agreement with previous measurements showing elevated cesium in the Capsule 6 graphite fuel holder associated with this fuel compact. The fraction of the compact europium inventory released from the particles and retained in the matrix was relatively high (approximately 6E-3), indicating release from intact particle coatings. The Ag-110m inventory in individual particles exhibited a very broad distribution, with some particles retaining =80% of the predicted inventory and others retaining less than 25%. The average degree of Ag-110m retention in 60 gamma counted particles was approximately 50%. This elevated silver release is in agreement with analysis of silver on the Capsule 6 components, which indicated an average release of 38% of the Capsule 6 inventory from the fuel compacts. In spite of the relatively high degree of silver release from the particles, virtually none of the Ag-110m released was found in the compact matrix, and presumably migrated out of the compact and was deposited on the irradiation capsule components. Release of all other fission products from the particles appears to be less than a single

  3. Ultrasonic compaction of granular geological materials.

    PubMed

    Feeney, Andrew; Sikaneta, Sakalima; Harkness, Patrick; Lucas, Margaret

    2017-04-01

    It has been shown that the compaction of granular materials for applications such as pharmaceutical tableting and plastic moulding can be enhanced by ultrasonic vibration of the compaction die. Ultrasonic vibrations can reduce the compaction pressure and increase particle fusion, leading to higher strength products. In this paper, the potential benefits of ultrasonics in the compaction of geological granular materials in downhole applications are explored, to gain insight into the effects of ultrasonic vibrations on compaction of different materials commonly encountered in sub-sea drilling. Ultrasonic vibrations are applied, using a resonant 20kHz compactor, to the compaction of loose sand and drill waste cuttings derived from oolitic limestone, clean quartz sandstone, and slate-phyllite. For each material, a higher strain for a given compaction pressure was achieved, with higher sample density compared to that in the case of an absence of ultrasonics. The relationships between the operational parameters of ultrasonic vibration amplitude and true strain rate are explored and shown to be dependent on the physical characteristics of the compacting materials.

  4. 7 CFR 51.608 - Fairly compact.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Consumer Standards for Celery Stalks Definitions § 51.608 Fairly compact. Fairly compact means that...

  5. 7 CFR 51.572 - Compact.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Celery Definitions § 51.572 Compact. Compact means that the branches on the stalk are...

  6. Compilation of small ribosomal subunit RNA structures.

    PubMed Central

    Neefs, J M; Van de Peer, Y; De Rijk, P; Chapelle, S; De Wachter, R

    1993-01-01

    The database on small ribosomal subunit RNA structure contained 1804 nucleotide sequences on April 23, 1993. This number comprises 365 eukaryotic, 65 archaeal, 1260 bacterial, 30 plastidial, and 84 mitochondrial sequences. These are stored in the form of an alignment in order to facilitate the use of the database as input for comparative studies on higher-order structure and for reconstruction of phylogenetic trees. The elements of the postulated secondary structure for each molecule are indicated by special symbols. The database is available on-line directly from the authors by ftp and can also be obtained from the EMBL nucleotide sequence library by electronic mail, ftp, and on CD ROM disk. PMID:8332525

  7. Rubisco small subunit gene family in cassava.

    PubMed

    Yeo, T W; Mak, Y M; Ho, K K

    1999-01-01

    Cassava leaves of two different cultivars, Brazil and Buloh, were used to isolate mRNA. The mRNA isolated was successfully used in the construction of cDNA libraries for each of the cultivars. The cDNA libraries were screened for members of ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit gene family and positive clones were sequenced. A total of seven different SSU genes, of which five were from cultivar Brazil and two were from cultivar Buloh, were isolated. Comparison results show that even though all the sequences are highly similar, they can be classified into three subfamilies. Homology between members of the same subfamily is higher than homology between members from the same cultivar.

  8. Analysis of the protective effects of the α2/δ subunit of voltage-gated Ca(2+) channels in brain injury.

    PubMed

    Kim, Tae Yeon; Niimi, Kimie; Takahashi, Eiki

    2017-01-15

    Voltage-gated Ca(2+) channels (VGCCs) are comprised of α1, α2/δ, β, and γ subunits. The pore-forming α1 subunit is essential for the proper functioning of Ca(2+) channels, while the α2/δ subunit interacts with components of the extracellular matrix. The α2/δ subunit is related in many neuropathological symptoms, including epilepsy and cerebellar ataxia. We previously reported that the mutant Cav.2.1α1 subunit has protective effects following brain injury. The present study aimed to investigate the effects of the α2/δ subunit inhibition alone and in combination with the inhibition of the Cav.2.1α1 subunit following brain injury by injecting Gabapentin using Cav.2.1α1 mutant heterozygous rolling Nagoya (rol/+) and wild-type (+/+) mice. Gabapentin binds to the α2/δ subunit and leads to Ca(2+) flow disturbance. A cryogenic method was used to induce brain injury. The mice pretreated with 100mg/kg Gabapentin exhibited a decrease in lesion size, while the 40mg/kg Gabapentin injection was effective in rol/+ mice but not +/+ mice. The administration of 100mg/kg Gabapentin also attenuated reactive astrocyte activity and neuronal degeneration; the pattern of results was similar to that for lesion size. An analysis of phosphorylated p38 (pp38) expression revealed that Gabapentin suppressed the p38 mitogen-activated protein kinase (MAPK) signaling cascade by interrupting glutamate-signaling induced by the inhibition of VGCCs. The present findings demonstrated that the administration of the α2/δ subunit inhibitor, Gabapentin, had neuroprotective effects following brain injury.

  9. Subunit vaccine efficacy against Botulinum neurotoxin subtypes.

    PubMed

    Henkel, James S; Tepp, William H; Przedpelski, Amanda; Fritz, Robert B; Johnson, Eric A; Barbieri, Joseph T

    2011-10-13

    Botulinum neurotoxins (BoNT) are classified into 7 serotypes (A-G) based upon neutralization by serotype-specific anti-sera. Several recombinant serotype-specific subunit BoNT vaccines have been developed, including a subunit vaccine comprising the receptor binding domain (HCR) of the BoNTs. Sequencing of the genes encoding BoNTs has identified variants (subtypes) that possess up to 32% primary amino acid variation among different BoNT serotypes. Studies were conducted to characterize the ability of the HCR of BoNT/A to protect against challenge by heterologous BoNT/A subtypes (A1-A3). High dose vaccination with HCR/A subtypes A1-A4 protected mice from challenge by heterologous BoNT/A subtype A1-A3, while low dose HCR vaccination yielded partial protection to heterologous BoNT/A subtype challenge. Absolute IgG titers to HCRs correlated to the dose of HCR used for vaccination, where HCR/A1 elicited an A1 subtype-specific IgG response, which was not observed with HCR/A2 vaccination. Survival of mice challenged to heterologous BoNT/A2 following low dose HCR/A1 vaccination correlated with elevated IgG titers directed to the denatured C-terminal sub-domain of HCR/A2, while survival of mice to heterologous BoNT/A1 following low dose HCR/A2 vaccination correlated to elevated IgG titers directed to native HCRc/A1. This implies that low dose vaccinations with HCR/A subtypes elicit unique IgG responses, and provides a basis to define how the host develops a neutralizing immune response to BoNT intoxication. These results may provide a reference for the development of pan-BoNT vaccines.

  10. Modeling of oil shale compaction during retorting

    SciTech Connect

    Schreiber, J.D.

    1986-06-01

    A model of oil shale compacting during retorting has been developed and incorporated into a one-dimensional retorting model. The model calculates the vertical stress distribution in a column of oil shale rubble and the degree of compaction that these stresses cause. A correlation was developed that relates shale grade, initial void volume, and vertical stress to the final compaction of the shale bed. The model then determines the gas pressure drip through the retort and the effects of the varying pressure on the retorting process. The model has been tested by simulating the Rio Blanco Oil Shale Company's Tract C-a Retort 1. The model calculates 8.1% compaction, whereas 12 to 16 compaction was measured in the retort; causes of the discrepancy between calculated and measured values are discussed. 14 refs., 10 figs., 2 tabs.

  11. Dynamic regulation of β1 subunit trafficking controls vascular contractility.

    PubMed

    Leo, M Dennis; Bannister, John P; Narayanan, Damodaran; Nair, Anitha; Grubbs, Jordan E; Gabrick, Kyle S; Boop, Frederick A; Jaggar, Jonathan H

    2014-02-11

    Ion channels composed of pore-forming and auxiliary subunits control physiological functions in virtually all cell types. A conventional view is that channels assemble with their auxiliary subunits before anterograde plasma membrane trafficking of the protein complex. Whether the multisubunit composition of surface channels is fixed following protein synthesis or flexible and open to acute and, potentially, rapid modulation to control activity and cellular excitability is unclear. Arterial smooth muscle cells (myocytes) express large-conductance Ca(2+)-activated potassium (BK) channel α and auxiliary β1 subunits that are functionally significant modulators of arterial contractility. Here, we show that native BKα subunits are primarily (∼95%) plasma membrane-localized in human and rat arterial myocytes. In contrast, only a small fraction (∼10%) of total β1 subunits are located at the cell surface. Immunofluorescence resonance energy transfer microscopy demonstrated that intracellular β1 subunits are stored within Rab11A-postive recycling endosomes. Nitric oxide (NO), acting via cGMP-dependent protein kinase, and cAMP-dependent pathways stimulated rapid (≤1 min) anterograde trafficking of β1 subunit-containing recycling endosomes, which increased surface β1 almost threefold. These β1 subunits associated with surface-resident BKα proteins, elevating channel Ca(2+) sensitivity and activity. Our data also show that rapid β1 subunit anterograde trafficking is the primary mechanism by which NO activates myocyte BK channels and induces vasodilation. In summary, we show that rapid β1 subunit surface trafficking controls functional BK channel activity in arterial myocytes and vascular contractility. Conceivably, regulated auxiliary subunit trafficking may control ion channel activity in a wide variety of cell types.

  12. Structure of the archaeal Cascade subunit Csa5: relating the small subunits of CRISPR effector complexes.

    PubMed

    Reeks, Judith; Graham, Shirley; Anderson, Linzi; Liu, Huanting; White, Malcolm F; Naismith, James H

    2013-05-01

    The Cascade complex for CRISPR-mediated antiviral immunity uses CRISPR RNA (crRNA) to target invading DNA species from mobile elements such as viruses, leading to their destruction. The core of the Cascade effector complex consists of the Cas5 and Cas7 subunits, which are widely conserved in prokaryotes. Cas7 binds crRNA and forms the helical backbone of Cascade. Many archaea encode a version of the Cascade complex (denoted Type I-A) that includes a Csa5 (or small) subunit, which interacts weakly with the core proteins. Here, we report the crystal structure of the Csa5 protein from Sulfolobus solfataricus. Csa5 comprises a conserved α-helical domain with a small insertion consisting of a weakly conserved β-strand domain. In the crystal, the Csa5 monomers have multimerized into infinite helical threads. At each interface is a strictly conserved intersubunit salt bridge, deletion of which disrupts multimerization. Structural analysis indicates a shared evolutionary history among the small subunits of the CRISPR effector complexes. The same α-helical domain is found in the C-terminal domain of Cse2 (from Type I-E Cascade), while the N-terminal domain of Cse2 is found in Cmr5 of the CMR (Type III-B) effector complex. As Cmr5 shares no match with Csa5, two possibilities present themselves: selective domain loss from an ancestral Cse2 to create two new subfamilies or domain fusion of two separate families to create a new Cse2 family. A definitive answer awaits structural studies of further small subunits from other CRISPR effector complexes.

  13. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    PubMed Central

    Tandrup Schmidt, Signe; Foged, Camilla; Smith Korsholm, Karen; Rades, Thomas; Christensen, Dennis

    2016-01-01

    The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce protective immunity, and they are often combined with adjuvants to ensure robust immune responses. Adjuvants are capable of enhancing and/or modulating immune responses by exposing antigens to antigen-presenting cells (APCs) concomitantly with conferring immune activation signals. Few adjuvant systems have been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI). Adjuvants constitute a heterogeneous group of compounds, which can broadly be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode. Immunostimulators represent highly diverse classes of molecules, e.g., lipids, nucleic acids, proteins and peptides, and they are ligands for pattern-recognition receptors (PRRs), which are differentially expressed on APC subsets. Different formulation strategies might thus be required for incorporation of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the specific PRR

  14. Enhancement of anion-exchange chromatography of DNA using compaction agents

    NASA Technical Reports Server (NTRS)

    Murphy, Jason C.; Fox, George E.; Willson, Richard C.

    2003-01-01

    The use of adsorptive chromatography for preparative nucleic acid separations is often limited by low capacity. The possibility that the adsorbent surface area sterically accessible to nucleic acid molecules could be increased by reducing their radius of gyration with compaction agents has been investigated. The equilibrium adsorption capacity of Q Sepharose anion-exchange matrix for plasmid DNA at 600 mM NaCl was enhanced by up to ca. 40% in the presence of 2.5 mM spermine. In addition, compaction agent selectivity has been demonstrated. Spermine, for example, enhances the adsorption of both plasmid and genomic DNA, spermidine enhances binding only of plasmid, and hexamine cobalt enhances only the binding of genomic DNA. Compaction may be generally useful for enhancing adsorptive separations of nucleic acids.

  15. Proliferation, angiogenesis and differentiation related markers in compact and follicular-compact thyroid carcinomas in dogs

    PubMed Central

    Pessina, P.; Castillo, V.A.; César, D.; Sartore, I.; Meikle, A.

    2016-01-01

    Immunohistochemical markers (IGF-1, IGF-1R, VEGF, FGF-2, RARα and RXR) were evaluated in healthy canine thyroid glands (n=8) and in follicular-compact (n=8) and compact thyroid carcinomas (n=8). IGF-1, IGF-1R and VEGF expression was higher in fibroblasts and endothelial cells of compact carcinoma than in healthy glands (P < 0.05). Compared to follicular-compact carcinoma, compact carcinoma had higher IGF-1R expression in fibroblasts, and higher FGF-2 expression in endothelial cells (P < 0.05). RARα expression was higher in endothelial cells of compact carcinoma than in those of other groups (P < 0.05). The upregulation of these proliferation- and angiogenesis-related factors in endothelial cells and/or fibroblasts and not in follicular cells of compact carcinoma compared to healthy glands supports the relevance of stromal cells in cancer progression. PMID:28116249

  16. Rheology Analysis of Thermosetting Resin Candidates for Use in Fuel Compacting

    SciTech Connect

    Trammell, Michael P.

    2012-06-01

    The AGR-1 and AGR-2 overcoating and compacting method utilized a wet mixing process where liquid resin (Hexion Durite SC-1008) was blended with natural and synthetic graphite to produce a graphite/resin matrix for overcoating. The matrix production method specified in the scale-up plan is a co-grinding jet mill process where powdered resin and graphite are fed at the same time into a jet mill. Because of the change in matrix production style, SC-1008 cannot be used in the jet milling process because it is a liquid. Also, attempts to dry out matrix made with SC-1008 for use in the overcoating process at B&W had mixed results. The SC-1008 resin became tacky when dried which caused the matrix to build up inside the overcoater. The scale- up jet milling/mixing and overcoating processes required that a suite of solid or powdered resins be identified. Suitable resins candidates were down selected to two resins, specifically Plenco 14838 and Hexion SD-1708. These resins are referred to as novolac or “two-stage” resins because they require the addition of a curing agent such as hexamethylenetetramine (Hexa) to promote an increased level of cross linking. The overcoating matrix is made of 3 components; natural graphite, synthetic graphite, and resin. The most influential component of the compacting process is the resin component and how it behaves with regards to time, temperature, and pressure. The selected scale-up resins are considered fast curing which means that the increase in molecular weight (curing) occurs over a relatively short period of time, ranging from a few seconds to several minutes depending on the temperature. To find the optimal compacting conditions it is useful to quantify this behavior. In this report, rheology is used to investigate viscosity as a function of time at specific temperatures for the previously mentioned resins.

  17. The diversity of GABA(A) receptor subunit distribution in the normal and Huntington's disease human brain.

    PubMed

    Waldvogel, H J; Faull, R L M

    2015-01-01

    GABA(A) receptors are assembled into pentameric receptor complexes from a total of 19 different subunits derived from a variety of different subunit classes (α1-6, β1-3, γ1-3, δ, ɛ, θ, and π) which surround a central chloride ion channel. GABA(A) receptor complexes are distributed heterogeneously throughout the brain and spinal cord and are activated by the extensive GABAergic inhibitory system. In this chapter, we describe the heterogeneous distribution of six of the most widely distributed subunits (α1, α2, α3, β2,3, and γ2) throughout the human basal ganglia. This review describes the studies we have carried out on the normal and Huntington's disease human basal ganglia using autoradiographic labeling and immunohistochemistry in the human basal ganglia. GABA(A) receptors are known to react to changing conditions in the brain in neurological disorders, especially in Huntington's disease and display a high degree of plasticity which is thought to compensate for loss of function caused by disease. In Huntington's disease, the variable loss of GABAergic medium spiny striatopallidal projection neurons is associated with a loss of GABA(A) receptor subunits in the striosome and/or the matrix compartments of the striatum. By contrast in the globus pallidus, a loss of the GABAergic striatal projection neurons results in a dramatic upregulation of subunits on the large postsynaptic pallidal neurons; this is thought to be a compensatory plastic mechanism resulting from the loss of striatal GABAergic input. Most interestingly, our studies have revealed that the subventricular zone overlying the caudate nucleus contains a variety of proliferating progenitor stem cells that possess a heterogeneity of GABA(A) receptor subunits which may play a role in human brain repair mechanisms.

  18. A compact optical fiber positioner

    NASA Astrophysics Data System (ADS)

    Hu, Hongzhuan; Wang, Jianping; Liu, Zhigang; Zhou, Zengxiang; Zhai, Chao; Chu, Jiaru

    2016-07-01

    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  19. Compact stellarators with modular coils.

    PubMed

    Garabedian, P R

    2000-07-18

    Compact stellarator designs with modular coils and only two or three field periods are now available; these designs have both good stability and quasiaxial symmetry providing adequate transport for a magnetic fusion reactor. If the bootstrap current assumes theoretically predicted values a three field period configuration is optimal, but if that net current turns out to be lower, a device with two periods and just 12 modular coils might be better. There are also attractive designs with quasihelical symmetry and four or five periods whose properties depend less on the bootstrap current. Good performance requires that there be a satisfactory magnetic well in the vacuum field, which is a property lacking in a stellarator-tokamak hybrid that has been proposed for a proof of principle experiment. In this paper, we present an analysis of stability for these configurations that is based on a mountain pass theorem asserting that, if two solutions of the problem of magnetohydrodynamic equilibrium can be found, then there has to be an unstable solution. We compare results of our theory of equilibrium, stability, and transport with recently announced measurements from the large LHD experiment in Japan.

  20. Compact stellarators with modular coils

    PubMed Central

    Garabedian, P. R.

    2000-01-01

    Compact stellarator designs with modular coils and only two or three field periods are now available; these designs have both good stability and quasiaxial symmetry providing adequate transport for a magnetic fusion reactor. If the bootstrap current assumes theoretically predicted values a three field period configuration is optimal, but if that net current turns out to be lower, a device with two periods and just 12 modular coils might be better. There are also attractive designs with quasihelical symmetry and four or five periods whose properties depend less on the bootstrap current. Good performance requires that there be a satisfactory magnetic well in the vacuum field, which is a property lacking in a stellarator-tokamak hybrid that has been proposed for a proof of principle experiment. In this paper, we present an analysis of stability for these configurations that is based on a mountain pass theorem asserting that, if two solutions of the problem of magnetohydrodynamic equilibrium can be found, then there has to be an unstable solution. We compare results of our theory of equilibrium, stability, and transport with recently announced measurements from the large LHD experiment in Japan. PMID:10899993

  1. Compact drilling and sample system

    NASA Technical Reports Server (NTRS)

    Gillis-Smith, Greg R.; Petercsak, Doug

    1998-01-01

    The Compact Drilling and Sample System (CDSS) was developed to drill into terrestrial, cometary, and asteroid material in a cryogenic, vacuum environment in order to acquire subsurface samples. Although drills were used by the Apollo astronauts some 20 years ago, this drill is a fraction of the mass and power and operates completely autonomously, able to drill, acquire, transport, dock, and release sample containers in science instruments. The CDSS has incorporated into its control system the ability to gather science data about the material being drilled by measuring drilling rate per force applied and torque. This drill will be able to optimize rotation and thrust in order to achieve the highest drilling rate possible in any given sample. The drill can be commanded to drill at a specified force, so that force imparted on the rover or lander is limited. This paper will discuss the cryo dc brush motors, carbide gears, cryogenic lubrication, quick-release interchangeable sampling drill bits, percussion drilling and the control system developed to achieve autonomous, cryogenic, vacuum, lightweight drilling.

  2. Ultra Compact Imaging Spectrometer (UCIS)

    NASA Astrophysics Data System (ADS)

    Blaney, Diana L.; Green, Robert; Mouroulis, Pantazis; Cable, Morgan; Ehlmann, Bethany; Haag, Justin; Lamborn, Andrew; McKinley, Ian; Rodriguez, Jose; van Gorp, Byron

    2016-10-01

    The Ultra Compact Imaging Spectrometer (UCIS) is a modular visible to short wavelength infrared imaging spectrometer architecture which could be adapted to a variety of mission concepts requiring low mass and low power. Imaging spectroscopy is an established technique to address complex questions of geologic evolution by mapping diagnostic absorption features due to minerals, organics, and volatiles throughout our solar system. At the core of UCIS is an Offner imaging spectrometer using M3 heritage and a miniature pulse tube cryo-cooler developed under the NASA Maturation of Instruments for Solar System Exploration (MatISSE) program to cool the focal plane array. The TRL 6 integrated spectrometer and cryo-cooler provide a basic imaging spectrometer capability that is used with a variety of fore optics to address lunar, mars, and small body science goals. Potential configurations include: remote sensing from small orbiters and flyby spacecraft; in situ panoramic imaging spectroscopy; and in situ micro-spectroscopy. A micro-spectroscopy front end is being developed using MatISSE funding with integration and testing planned this summer.

  3. Dynamic compaction of granular materials

    PubMed Central

    Favrie, N.; Gavrilyuk, S.

    2013-01-01

    An Eulerian hyperbolic multiphase flow model for dynamic and irreversible compaction of granular materials is constructed. The reversible model is first constructed on the basis of the classical Hertz theory. The irreversible model is then derived in accordance with the following two basic principles. First, the entropy inequality is satisfied by the model. Second, the corresponding ‘intergranular stress’ coming from elastic energy owing to contact between grains decreases in time (the granular media behave as Maxwell-type materials). The irreversible model admits an equilibrium state corresponding to von Mises-type yield limit. The yield limit depends on the volume fraction of the solid. The sound velocity at the yield surface is smaller than that in the reversible model. The last one is smaller than the sound velocity in the irreversible model. Such an embedded model structure assures a thermodynamically correct formulation of the model of granular materials. The model is validated on quasi-static experiments on loading–unloading cycles. The experimentally observed hysteresis phenomena were numerically confirmed with a good accuracy by the proposed model. PMID:24353466

  4. Compact IR synchrotron beamline design.

    PubMed

    Moreno, Thierry

    2017-03-01

    Third-generation storage rings are massively evolving due to the very compact nature of the multi-bend achromat (MBA) lattice which allows amazing decreases of the horizontal electron beam emittance, but leaves very little place for infrared (IR) extraction mirrors to be placed, thus prohibiting traditional IR beamlines. In order to circumvent this apparent restriction, an optimized optical layout directly integrated inside a SOLEIL synchrotron dipole chamber that delivers intense and almost aberration-free beams in the near- to mid-IR domain (1-30 µm) is proposed and analyzed, and which can be integrated into space-restricted MBA rings. Since the optics and chamber are interdependent, the feasibility of this approach depends on a large part on the technical ability to assemble mechanically the optics inside the dipole chamber and control their resulting stability and thermo-mechanical deformation. Acquiring this expertise should allow dipole chambers to provide almost aberration-free IR synchrotron sources on current and `ultimate' MBA storage rings.

  5. Epitopes from two soybean glycinin subunits antigenic in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Glycinin is a seed storage protein in soybean (Glycine max) that is allergenic in pigs. Glycinin is a hexamer composed of subunits consisting of a basic and acidic portion joined by disulfide bridges. There are 5 glycinin subunits designated Gy1-Gy5. Results: Twenty seven out of 30 pi...

  6. Specific Roles of NMDA Receptor Subunits in Mental Disorders

    PubMed Central

    Yamamoto, H.; Hagino, Y.; Kasai, S.; Ikeda, K.

    2015-01-01

    N-methyl-D-aspartate (NMDA) receptor plays important roles in learning and memory. NMDA receptors are a tetramer that consists of two glycine-binding subunits GluN1, two glutamate-binding subunits (i.e., GluN2A, GluN2B, GluN2C, and GluN2D), a combination of a GluN2 subunit and glycine-binding GluN3 subunit (i.e., GluN3A or GluN3B), or two GluN3 subunits. Recent studies revealed that the specific expression and distribution of each subunit are deeply involved in neural excitability, plasticity, and synaptic deficits. The present article summarizes reports on the dysfunction of NMDA receptors and responsible subunits in various neurological and psychiatric disorders, including schizophrenia, autoimmune-induced glutamatergic receptor dysfunction, mood disorders, and autism. A key role for the GluN2D subunit in NMDA receptor antagonist-induced psychosis has been recently revealed. PMID:25817860

  7. Proteopedia Entry: The Large Ribosomal Subunit of "Haloarcula Marismortui"

    ERIC Educational Resources Information Center

    Decatur, Wayne A.

    2010-01-01

    This article presents a "Proteopedia" page that shows the refined version of the structure of the "Haloarcula" large ribosomal subunit as solved by the laboratories of Thomas Steitz and Peter Moore. The landmark structure is of great impact as it is the first atomic-resolution structure of the highly conserved ribosomal subunit which harbors…

  8. Automatic switching matrix

    DOEpatents

    Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

    1982-01-01

    An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

  9. Mutational analysis of muscle nicotinic acetylcholine receptor subunit assembly

    PubMed Central

    1990-01-01

    The structural elements required for normal maturation and assembly of the nicotinic acetylcholine receptor alpha subunit were investigated by expression of mutated subunits in transfected fibroblasts. Normally, the wild-type alpha subunit acquires high affinity alpha bungarotoxin binding in a time-dependent manner; however, mutation of the 128 and/or 142 cysteines to either serine or alanine, as well as deletion of the entire 14 amino acids in this region abolished all detectable high affinity binding. Nonglycosylated subunits that had a serine to glycine mutation in the consensus sequence also did not efficiently attain high affinity binding to toxin. In contrast, mutation of the proline at position 136 to glycine or alanine, or a double mutation of the cysteines at position 192 and 193 to serines had no effect on the acquisition of high affinity toxin binding. These data suggest that a disulfide bridge between cysteines 128 and 142 and oligosaccharide addition at asparagine 141 are required for the normal maturation of alpha subunit as assayed by high affinity toxin binding. The unassembled wild-type alpha subunit expressed in fibroblasts is normally degraded with a t1/2 of 2 h; upon assembly with the delta subunit, the degradation rate slows significantly (t1/2 greater than 13 h). All mutated alpha subunits retained the capacity to assemble with a delta subunit coexpressed in fibroblasts; however, mutated alpha subunits that were not glycosylated or did not acquire high affinity toxin binding were rapidly degraded (t1/2 = 20 min to 2 h) regardless of whether or not they assembled with the delta subunit. Assembly and rapid degradation of nonglycosylated acetylcholine receptor (AChR) subunits and subunit complexes were also observed in tunicamycin- treated BC3H-1 cells, a mouse musclelike cell line that normally expresses functional AChR. Hence, rapid degradation may be one form of regulation assuring that only correctly processed and assembled subunits

  10. Geranyl diphosphate synthase large subunit, and methods of use

    DOEpatents

    Croteau, Rodney B.; Burke, Charles C.; Wildung, Mark R.

    2001-10-16

    A cDNA encoding geranyl diphosphate synthase large subunit from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase large subunit). In another aspect, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase large subunit. In yet another aspect, the present invention provides isolated, recombinant geranyl diphosphate synthase protein comprising an isolated, recombinant geranyl diphosphate synthase large subunit protein and an isolated, recombinant geranyl diphosphate synthase small subunit protein. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase.

  11. The classification of 2 -compact groups

    NASA Astrophysics Data System (ADS)

    Andersen, Kasper K. S.; Grodal, Jesper

    2009-04-01

    We prove that any connected 2 -compact group is classified by its 2 -adic root datum, and in particular the exotic 2 -compact group operatorname{DI}(4) , constructed by Dwyer-Wilkerson, is the only simple 2 -compact group not arising as the 2 -completion of a compact connected Lie group. Combined with our earlier work with Mo/ller and Viruel for p odd, this establishes the full classification of p -compact groups, stating that, up to isomorphism, there is a one-to-one correspondence between connected p -compact groups and root data over the p -adic integers. As a consequence we prove the maximal torus conjecture, giving a one-to-one correspondence between compact Lie groups and finite loop spaces admitting a maximal torus. Our proof is a general induction on the dimension of the group, which works for all primes. It refines the Andersen-Grodal-Mo/ller-Viruel methods by incorporating the theory of root data over the p -adic integers, as developed by Dwyer-Wilkerson and the authors. Furthermore we devise a different way of dealing with the rigidification problem by utilizing obstruction groups calculated by Jackowski-McClure-Oliver in the early 1990s.

  12. Foster Wheeler compact CFB boiler with INTREX

    SciTech Connect

    Hyppaenen, T.; Rainio, A.; Kauppinen, K.V.O.; Stone, J.E.

    1997-12-31

    Foster Wheeler has introduced a new COMPACT Circulating Fluidized Bed (CFB) boiler design based on the rectangular hot solids separator. The Compact design also enables easy implementation of new designs for INTREX fluid bed heat exchangers. These new products result in many benefits which affect the boiler economy and operation. After initial development of the Compact CFB design it has been applied in demonstration and industrial scale units. The performance of Compact CFB has been proved to be equivalent to conventional Foster Wheeler CFB has been proved to be equivalent to conventional Foster Wheeler CFB boilers with high availability. Several new Foster Wheeler Compact boilers are being built or already in operation. Operational experiences from different units will be discussed in this paper. There are currently Compact units with 100--150 MW{sub e} capacity under construction. With the scale-up experience with conventional CFB boilers and proven design approach and scale-up steps, Foster Wheeler will have the ability to provide large Compact CFB boilers up to 400--600 MW{sub e} capacity.

  13. A revised model for AMP-activated protein kinase structure: The alpha-subunit binds to both the beta- and gamma-subunits although there is no direct binding between the beta- and gamma-subunits.

    PubMed

    Wong, Kelly A; Lodish, Harvey F

    2006-11-24

    The 5'-AMP-activated protein kinase (AMPK) is a master sensor for cellular metabolic energy state. It is activated by a high AMP/ATP ratio and leads to metabolic changes that conserve energy and utilize alternative cellular fuel sources. The kinase is composed of a heterotrimeric protein complex containing a catalytic alpha-subunit, an AMP-binding gamma-subunit, and a scaffolding beta-subunit thought to bind directly both the alpha- and gamma-subunits. Here, we use coimmunoprecipitation of proteins in transiently transfected cells to show that the alpha2-subunit binds directly not only to the beta-subunit, confirming previous work, but also to the gamma1-subunit. Deletion analysis of the alpha2-subunit reveals that the C-terminal 386-552 residues are sufficient to bind to the beta-subunit. The gamma1-subunit binds directly to the alpha2-subunit at two interaction sites, one within the catalytic domain consisting of alpha2 amino acids 1-312 and a second within residues 386-552. Binding of the alpha2 and the gamma1-subunits was not affected by 400 mum AMP or ATP. Furthermore, we show that the beta-subunit C terminus is essential for binding to the alpha2-subunit but, in contrast to previous work, the beta-subunit does not bind directly to the gamma1-subunit. Taken together, this study presents a new model for AMPK heterotrimer structure where through its C terminus the beta-subunit binds to the alpha-subunit that, in turn, binds to the gamma-subunit. There is no direct interaction between the beta- and gamma-subunits.

  14. The subunit composition and function of mammalian cytochrome c oxidase.

    PubMed

    Kadenbach, Bernhard; Hüttemann, Maik

    2015-09-01

    Cytochrome c oxidase (COX) from mammals and birds is composed of 13 subunits. The three catalytic subunits I-III are encoded by mitochondrial DNA, the ten nuclear-coded subunits (IV, Va, Vb, VIa, VIb, VIc, VIIa, VIIb, VIIc, VIII) by nuclear DNA. The nuclear-coded subunits are essentially involved in the regulation of oxygen consumption and proton translocation by COX, since their removal or modification changes the activity and their mutation causes mitochondrial diseases. Respiration, the basis for ATP synthesis in mitochondria, is differently regulated in organs and species by expression of tissue-, developmental-, and species-specific isoforms for COX subunits IV, VIa, VIb, VIIa, VIIb, and VIII, but the holoenzyme in mammals is always composed of 13 subunits. Various proteins and enzymes were shown, e.g., by co-immunoprecipitation, to bind to specific COX subunits and modify its activity, but these interactions are reversible, in contrast to the tightly bound 13 subunits. In addition, the formation of supercomplexes with other oxidative phosphorylation complexes has been shown to be largely variable. The regulatory complexity of COX is increased by protein phosphorylation. Up to now 18 phosphorylation sites have been identified under in vivo conditions in mammals. However, only for a few phosphorylation sites and four nuclear-coded subunits could a specific function be identified. Research on the signaling pathways leading to specific COX phosphorylations remains a great challenge for understanding the regulation of respiration and ATP synthesis in mammalian organisms. This article reviews the function of the individual COX subunits and their isoforms, as well as proteins and small molecules interacting and regulating the enzyme.

  15. Subunit structure of the follitropin receptor

    SciTech Connect

    Shin, J.

    1985-01-01

    Both of the ..cap alpha.. and ..beta.. subunits of intact human follitropin (FSH) were radioiodinated with /sup 125/I-FSH-sodium iodide and chloramine-T, and could be resolved on polyacrylamide gels (SDS-PAGE). The electrophoretic mobility of radioiodinated FSH ..cap alpha.. and ..beta.. subunits as well as the ..cap alpha beta.. dimer changed markedly depending on the concentration of reducing agents. /sup 125/I-FSH (Ka = 1.4 x 10/sup 10/ M/sup -1/), complexes to the receptor on procine granulosa cells or in Triton X-100 extracts, was affinity-crosslinked with a cleavable (nondisulfide) homobifunctional reagent, bis(2-(succinimidooxycarbonyloxy)ethyl)sulfone, solubilized in sodium dodecyl sulfate with or without reducing agents, and electrophoresed. Crosslinked samples revealed three additional bands of slower electrophoretic mobility, corresponding to 65 (unreduced 62), 83 (unreduced 76) and 117 (unreduced 110)kDa, in addition to hormone bands. Formation of the three bands requires the /sup 125/I-FSH hormone to bind specifically to the receptor with subsequent cross-linking. The rate of formation and cleavage of the cross-linked complexes indicated a sequential and incremental addition of 22, 18, and 34 kDa components to the FSH ..cap alpha beta.. dimer. The results of reduction of cross-linked complexes demonstrated the existence of disulfide linkage between the three components. FSH was photoactively derivatized with N-hydroxysuccinimide ester of 4-azidobenzolyl-glycine and radioiodinated for photoaffinity labeling. When derivatized /sup 125/I-FSH (Ka = 1.12 10/sup 10/ M/sup -1/) bound to the cell was photolyzed for cross-linking and resolved on the SDS-PAGE, two new bands (106 and 61 kDa) under reducing condition appeared in addition to the hormone bands. Upon reduction with dithiotheitol and second-dimensional electrophoresis, the unreduced 104 kDa (reduced 106 kDa) band released two small components 31 and 14 kDa.

  16. Strategy Guideline. Compact Air Distribution Systems

    SciTech Connect

    Burdick, Arlan

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  17. Model building with non-compact cosets

    NASA Astrophysics Data System (ADS)

    Croon, Djuna Lize

    2016-11-01

    We explore Goldstone boson potentials in non-compact cosets of the form SO (n , 1) / SO (n). We employ a geometric approach to find the scalar potential, and focus on the conditions under which it is compact in the large field limit. We show that such a potential is found for a specific misalignment of the vacuum. This result has applications in different contexts, such as in Composite Higgs scenarios and theories for the Early Universe. We work out an example of inflation based on a non-compact coset which makes predictions which are consistent with the current observational data.

  18. Compacting a Kentucky coal for quality logs

    SciTech Connect

    Lin, Y.; Li, Z.; Mao, S.

    1999-07-01

    A Kentucky coal was found more difficult to be compacted into large size strong logs. Study showed that compaction parameters affecting the strength of compacted coal logs could be categorized into three groups. The first group is coal inherent properties such as elasticity and coefficient of friction, the second group is machine properties such as mold geometry, and the third group is the coal mixture preparation parameters such as particle size distribution. Theoretical analysis showed that an appropriate backpressure can reduce surface cracks occurring during ejection. This has been confirmed by the experiments conducted.

  19. Na, K ATPase beta3 subunit (CD298): association with alpha subunit and expression on peripheral blood cells.

    PubMed

    Chiampanichayakul, S; Khunkaewla, P; Pata, S; Kasinrerk, W

    2006-12-01

    Beta3 subunit is described as one of the Na, K ATPase subunits. Recently, we generated a monoclonal antibody (mAb), termed P-3E10. This mAb was shown to react with the Na, K ATPase beta3 subunit or CD298. By immunofluorescence analysis using mAb P-3E10, it was found that all peripheral blood leukocytes express Na, K ATPase beta3. The presence of beta3 subunit on leukocytes is not in a quantitative polymorphic manner. Upon phytohemagglutinin or phorbol myristate acetate activation, the expression level of the Na, K ATPase beta3 subunit on activated peripheral blood mononuclear cells was not altered in comparison with those of unstimulated cells. Red blood cells (RBCs) of healthy donors showed negative reactivity with mAb P-3E10. However, more than 80% of thalassemic RBCs showed positive reactivity. By immunoprecipitation, moreover, a protein band of 55-65 kDa was precipitated from normal RBC membrane using mAb P-3E10. These results evidenced that the beta3 subunit of Na, K ATPase is expressed on RBC membrane but the epitope recognized by mAb P-3E10 is hidden in normal RBCs. Furthermore, we showed the association of beta3 subunit and alpha subunit of Na, K ATPase. This information is important for further understanding of the functional roles of this molecule.

  20. Equilibrium calculations for plasma control in CIT (Compact Ignition Tokamak)

    SciTech Connect

    Strickler, D.J.; Peng, Y-K.M. . Fusion Engineering Design Center); Pomphrey, N.; Jardin, S.C. . Plasma Physics Lab.)

    1990-01-01

    The free-boundary equilibrium code VEQ provides equilibrium data that are used by the Tokamak Simulation Code (TSC) in design and analysis of the poloidal field (PF) system for the Compact Ignition Tokamak (CIT). VEQ serves as an important design tool for locating the PF coils and defining coil current trajectories and control systems for TSC. In this report, VEQ and its role in the TSC analysis of the CIT PF system are described. Equilibrium and coil current calculations are discussed, an overview of the CIT PF system is presented, a set of reference equilibria for modeling a complete discharge in CIT is described, and the concept of a plasma shape control matrix is introduced. 9 refs., 8 figs., 7 tabs.

  1. Global chromatin fibre compaction in response to DNA damage

    SciTech Connect

    Hamilton, Charlotte; Hayward, Richard L.; Gilbert, Nick

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Robust KAP1 phosphorylation in response to DNA damage in HCT116 cells. Black-Right-Pointing-Pointer DNA repair foci are found in soluble chromatin. Black-Right-Pointing-Pointer Biophysical analysis reveals global chromatin fibre compaction after DNA damage. Black-Right-Pointing-Pointer DNA damage is accompanied by rapid linker histone dephosphorylation. -- Abstract: DNA is protected by packaging it into higher order chromatin fibres, but this can impede nuclear processes like DNA repair. Despite considerable research into the factors required for signalling and repairing DNA damage, it is unclear if there are concomitant changes in global chromatin fibre structure. In human cells DNA double strand break (DSB) formation triggers a signalling cascade resulting in H2AX phosphorylation ({gamma}H2AX), the rapid recruitment of chromatin associated proteins and the subsequent repair of damaged sites. KAP1 is a transcriptional corepressor and in HCT116 cells we found that after DSB formation by chemicals or ionising radiation there was a wave of, predominantly ATM dependent, KAP1 phosphorylation. Both KAP1 and phosphorylated KAP1 were readily extracted from cells indicating they do not have a structural role and {gamma}H2AX was extracted in soluble chromatin indicating that sites of damage are not attached to an underlying structural matrix. After DSB formation we did not find a concomitant change in the sensitivity of chromatin fibres to micrococcal nuclease digestion. Therefore to directly investigate higher order chromatin fibre structures we used a biophysical sedimentation technique based on sucrose gradient centrifugation to compare the conformation of chromatin fibres isolated from cells before and after DNA DSB formation. After damage we found global chromatin fibre compaction, accompanied by rapid linker histone dephosphorylation, consistent with fibres being more regularly folded or fibre deformation being stabilized by

  2. Compactly supported Wannier functions and algebraic K -theory

    NASA Astrophysics Data System (ADS)

    Read, N.

    2017-03-01

    In a tight-binding lattice model with n orbitals (single-particle states) per site, Wannier functions are n -component vector functions of position that fall off rapidly away from some location, and such that a set of them in some sense span all states in a given energy band or set of bands; compactly supported Wannier functions are such functions that vanish outside a bounded region. They arise not only in band theory, but also in connection with tensor-network states for noninteracting fermion systems, and for flat-band Hamiltonians with strictly short-range hopping matrix elements. In earlier work, it was proved that for general complex band structures (vector bundles) or general complex Hamiltonians—that is, class A in the tenfold classification of Hamiltonians and band structures—a set of compactly supported Wannier functions can span the vector bundle only if the bundle is topologically trivial, in any dimension d of space, even when use of an overcomplete set of such functions is permitted. This implied that, for a free-fermion tensor network state with a nontrivial bundle in class A, any strictly short-range parent Hamiltonian must be gapless. Here, this result is extended to all ten symmetry classes of band structures without additional crystallographic symmetries, with the result that in general the nontrivial bundles that can arise from compactly supported Wannier-type functions are those that may possess, in each of d directions, the nontrivial winding that can occur in the same symmetry class in one dimension, but nothing else. The results are obtained from a very natural usage of algebraic K -theory, based on a ring of polynomials in e±i kx,e±i ky,..., which occur as entries in the Fourier-transformed Wannier functions.

  3. A compact laser target designator

    NASA Astrophysics Data System (ADS)

    Lee, S. T.; Silver, M.; Barron, A.; Borthwick, A.; Morton, G.; McRae, I.; Coghill, M.; Smith, C.; Scouler, C.; Gardiner, G.; Imlach, N.; McNeill, C.; McSporran, D.; Rodgers, D.; Kerr, D.; Alexander, W.

    2016-05-01

    Lasers intended for application to man-portable and hand-held laser target designators are subject to significant constraints on size, weight, power consumption and cost. These constraints must be met while maintaining adequate performance across a challenging environmental specification. One of the challenges of operating a Nd3+:YAG laser over a broad ambient temperature range is that of diode-pump-tuning. This system is specified to operate over an ambient temperature range of -46°C to +71°C, and the system electrical power consumption requirements preclude active temperature control. As a result the laser must tolerate a 32.8nm pump wavelength range. The optical absorption of Nd3+:YAG varies dramatically over this wavelength range. This paper presents a laser that minimizes the effect of this change on laser output. A folded U-shaped geometry laser resonator is presented, made up of a corner cube at one end and a plane mirror substrate at the other. The action of the corner cube coupled with this configuration of end mirrors results in a resonator that is significantly less sensitive to misalignment of the end mirror and/or the corner cube. This Ushaped resonator is then further folded to fit the laser into a smaller volume. Insensitivity of this compact folded resonator to mirror misalignments was analyzed in Zemax via a Monte-Carlo analysis and the results of this analysis are presented. The resulting laser output energy, pulse duration and beam quality of this athermally pumped, misalignment insensitive folded laser resonator are presented over an ambient temperature range of -46°C to +71°C.

  4. Measurements of elastic moduli of pharmaceutical compacts: a new methodology using double compaction on a compaction simulator.

    PubMed

    Mazel, Vincent; Busignies, Virginie; Diarra, Harona; Tchoreloff, Pierre

    2012-06-01

    The elastic properties of pharmaceutical powders play an important role during the compaction process. The elastic behavior can be represented by Young's modulus (E) and Poisson's ratio (v). However, during the compaction, the density of the powder bed changes and the moduli must be determined as a function of the porosity. This study proposes a new methodology to determine E and v as a function of the porosity using double compaction in an instrumented compaction simulator. Precompression is used to form the compact, and the elastic properties are measured during the beginning of the main compaction. By measuring the axial and radial pressure and the powder bed thickness, E and v can be determined as a function of the porosity. Two excipients were studied, microcrystalline cellulose (MCC) and anhydrous calcium phosphate (aCP). The values of E measured are comparable to those obtained using the classical three-point bending test. Poisson's ratio was found to be close to 0.24 for aCP with only small variations with the porosity, and to increase with a decreasing porosity for MCC (0.23-0.38). The classical approximation of a value of 0.3 for ν of pharmaceutical powders should therefore be taken with caution.

  5. [A promoter responsible for over-expression of cholera toxin B subunit in cholera toxin A subunit structure gene].

    PubMed

    Cao, C; Shi, C; Li, P; Ma, Q

    1997-01-01

    A promoter sequence, which promotes the transcription of cholera toxin B subunit gene, was found in cholera toxin A subunit structure gene. The transcription starts at the adenine Located at +833, that is 456bp upstream to the A of the initiation codon ATG of cholera toxin B gene. Under the control of the promoter, cholera toxin B subunit was over-expressed as high as 200 mg/L at an optimized culture condition. The chloramphenicol acetyl transferase gene and beta-galactosidase could also be efficiently expressed under the direction of the promoter. This promoter may be responsible for the 6 fold and 7 fold higher expression level of cholera toxin B subunit than cholera toxin A subunit in V. cholerae and Escheria coli respectively. The over-expression of CTB may be useful in preparing vaccine against cholera and facilitating the construction of peptide-bearing immunogenic hybrid proteins.

  6. General expressions for the matrix elements of the tight-binding operator within the Racah-Wigner algebra*

    NASA Astrophysics Data System (ADS)

    Möller, Thomas

    2016-12-01

    General expressions for the matrix elements of the tight-binding operator are presented using the Racah-Wigner algebra, where the wave functions are expressed as coupled multiplet wave functions within a given angular momentum coupling scheme. The knowledge of all possible Slater determinants is not necessary and the matrix elements can be written as compact expressions computable with arbitrary accuracy.

  7. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry.

    PubMed

    Rey-Raap, Natalia; Gallardo, Antonio

    2012-05-01

    In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52±0.4ppb of mercury in the vapor phase, 204.16±8.9ppb of mercury in the phosphor powder, and 18.74±0.5ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  8. Regulation of the primary quinone binding conformation by the H subunit in reaction centers from Rhodobacter sphaeroides.

    PubMed

    Sun, Chang; Taguchi, Alexander T; Beal, Nathan J; O'Malley, Patrick J; Dikanov, Sergei A; Wraight, Colin A

    2015-11-19

    Unlike photosystem II (PSII) in higher plants, bacterial photosynthetic reaction centers (bRCs) from Proteobacteria have an additional peripheral membrane subunit "H". The H subunit is necessary for photosynthetic growth, but can be removed chemically in vitro. The remaining LM dimer retains its activity to perform light-induced charge separation. Here we investigate the influence of the H subunit on interactions between the primary semiquinone and the protein matrix, using a combination of site-specific isotope labeling, pulsed electron paramagnetic resonance (EPR), and density functional theory (DFT) calculations. The data reveal substantially weaker binding interactions between the primary semiquinone and the LM dimer than observed for the intact bRC; the amount of electron spin transferred to the nitrogen hydrogen bond donors is significantly reduced, the methoxy groups are more free to rotate, and the spectra indicate a heterogeneous mixture of bound semiquinone states. These results are consistent with a loosening of the primary quinone binding pocket in the absence of the H subunit.

  9. Hacking the Matrix.

    PubMed

    Czerwinski, Michael; Spence, Jason R

    2017-01-05

    Recently in Nature, Gjorevski et al. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support in vitro growth of intestinal stem cells and organoids. The hydrogel allows exquisite control over the chemical and physical in vitro niche and enables identification of regulatory properties of the matrix.

  10. Fuzzy risk matrix.

    PubMed

    Markowski, Adam S; Mannan, M Sam

    2008-11-15

    A risk matrix is a mechanism to characterize and rank process risks that are typically identified through one or more multifunctional reviews (e.g., process hazard analysis, audits, or incident investigation). This paper describes a procedure for developing a fuzzy risk matrix that may be used for emerging fuzzy logic applications in different safety analyses (e.g., LOPA). The fuzzification of frequency and severity of the consequences of the incident scenario are described which are basic inputs for fuzzy risk matrix. Subsequently using different design of risk matrix, fuzzy rules are established enabling the development of fuzzy risk matrices. Three types of fuzzy risk matrix have been developed (low-cost, standard, and high-cost), and using a distillation column case study, the effect of the design on final defuzzified risk index is demonstrated.

  11. Deep Compaction Control of Sandy Soils

    NASA Astrophysics Data System (ADS)

    Bałachowski, Lech; Kurek, Norbert

    2015-02-01

    Vibroflotation, vibratory compaction, micro-blasting or heavy tamping are typical improvement methods for the cohesionless deposits of high thickness. The complex mechanism of deep soil compaction is related to void ratio decrease with grain rearrangements, lateral stress increase, prestressing effect of certain number of load cycles, water pressure dissipation, aging and other effects. Calibration chamber based interpretation of CPTU/DMT can be used to take into account vertical and horizontal stress and void ratio effects. Some examples of interpretation of soundings in pre-treated and compacted sands are given. Some acceptance criteria for compaction control are discussed. The improvement factors are analysed including the normalised approach based on the soil behaviour type index.

  12. Steady state compact toroidal plasma production

    DOEpatents

    Turner, William C.

    1986-01-01

    Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

  13. Altered 40 S ribosomal subunits in omnipotent suppressors of yeast.

    PubMed

    Eustice, D C; Wakem, L P; Wilhelm, J M; Sherman, F

    1986-03-20

    The five suppressors SUP35, SUP43, SUP44, SUP45 and SUP46, each mapping at a different chromosomal locus in the yeast Saccharomyces cerevisiae, suppress a wide range of mutations, including representatives of all three types of nonsense mutations, UAA, UAG and UGA. We have demonstrated that ribosomes from the four suppressors SUP35, SUP44, SUP45 and SUP46 translate polyuridylate templates in vitro with higher errors than ribosomes from the normal stain, and that this misreading is substantially enhanced by the antibiotic paromomycin. Furthermore, ribosomal subunit mixing experiments established that the 40 S ribosomal subunit, and this subunit only, is responsible for the higher levels of misreading. Thus, the gene products of SUP35, SUP44, SUP45 and SUP46 are components of the 40 S subunit or are enzymes that modify the subunit. In addition, a protein from the 40 S subunit of the SUP35 suppressor has an altered electrophoretic mobility; this protein is distinct from the altered protein previously uncovered in the 40 S subunit of the SUP46 suppressor. In contrast to the ribosomes from the four suppressors SUP35, SUP44, SUP45 and SUP46, the ribosomes from the SUP43 suppressor do not significantly misread polyuridylate templates in vitro, suggesting that this locus may not encode a ribosomal component or that the misreading is highly specific.

  14. Interactions between the human RNA polymerase II subunits.

    PubMed

    Acker, J; de Graaff, M; Cheynel, I; Khazak, V; Kedinger, C; Vigneron, M

    1997-07-04

    As an initial approach to characterizing the molecular structure of the human RNA polymerase II (hRPB), we systematically investigated the protein-protein contacts that the subunits of this enzyme may establish with each other. To this end, we applied a glutathione S-transferase-pulldown assay to extracts from Sf9 insect cells, which were coinfected with all possible combinations of recombinant baculoviruses expressing hRPB subunits, either as untagged polypeptides or as glutathione S-transferase fusion proteins. This is the first comprehensive study of interactions between eukaryotic RNA polymerase subunits; among the 116 combinations of hRPB subunits tested, 56 showed significant to strong interactions, whereas 60 were negative. Within the intricate network of interactions, subunits hRPB3 and hRPB5 play a central role in polymerase organization. These subunits, which are able to homodimerize and to interact, may constitute the nucleation center for polymerase assembly, by providing a large interface to most of the other subunits.

  15. Tidal deformability of compact boson stars

    NASA Astrophysics Data System (ADS)

    Sennett, Noah; Steinhoff, Jan; Hinderer, Tanja; Buonanno, Alessandra

    2017-01-01

    Gravitational waves can be used to probe the structure of compact objects in coalescing binary systems. This structure enters the pre-merger waveform through tidal interactions between the two bodies, characterized by each object's tidal deformability. We investigate whether these effects can differentiate binary black holes from systems containing compact boson stars. We compute the tidal deformability for various boson star models, including ultracompact non-topological solitonic solutions.

  16. Development of an optimized compact test range

    NASA Astrophysics Data System (ADS)

    Dudok, Evert; Fasold, Dietmar; Steiner, Hans-Juergen

    A method of measuring the electromagnetic far field characteristics of microwave antennas is introduced by means of compact test ranges. The performances of the front-fed Cassegrain system, which avoids the usually weak cross-polarization performance of the compact range geometries, are established. The chosen manufacturing process, milling of cast-iron reflectors, guaranteed highest achievable surface accuracies, even for very large reflectors. The structural analysis showed that extremely high surface accuracies require well regulated temperature conditions of the experiment.

  17. Rotating compact star with superconducting quark matter

    SciTech Connect

    Panda, P.K.; Nataraj, H.S.

    2006-02-15

    A compact star with a superconducting quark core, a hadron crust, and a mixed phase between the two is considered. The quark-meson coupling model for hadron matter and the color-flavor-locked quark model for quark matter is used to construct the equation of state for the compact star. The effect of pairing of quarks in the color-flavor-locked phase and the mixed phase on the mass, radius, and period of the rotating star is studied.

  18. Compact Proton Accelerator for Cancer Therapy

    SciTech Connect

    Chen, Y; Paul, A C

    2007-06-12

    An investigation is being made into the feasibility of making a compact proton dielectric wall (DWA) accelerator for medical radiation treatment based on the high gradient insulation (HGI) technology. A small plasma device is used for the proton source. Using only electric focusing fields for transporting and focusing the beam on the patient, the compact DWA proton accelerator m system can deliver wide and independent variable ranges of beam currents, energies and spot sizes.

  19. Compact fission counter for DANCE

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

    2010-11-06

    and still be able to maintain a stable operation under extreme radioactivity and the ability to separate fission fragments from {alpha}'s. In the following sections, the description is given for the design and performance of this new compact PPAC, for studying the neutron-induced reactions on actinides using DANCE at LANL.

  20. Echinococcus granulosus Antigen B Structure: Subunit Composition and Oligomeric States

    PubMed Central

    Monteiro, Karina M.; Cardoso, Mateus B.; Follmer, Cristian; da Silveira, Nádya P.; Vargas, Daiani M.; Kitajima, Elliot W.; Zaha, Arnaldo; Ferreira, Henrique B.

    2012-01-01

    Background Antigen B (AgB) is the major protein secreted by the Echinococcus granulosus metacestode and is involved in key host-parasite interactions during infection. The full comprehension of AgB functions depends on the elucidation of several structural aspects that remain unknown, such as its subunit composition and oligomeric states. Methodology/Principal Findings The subunit composition of E. granulosus AgB oligomers from individual bovine and human cysts was assessed by mass spectrometry associated with electrophoretic analysis. AgB8/1, AgB8/2, AgB8/3 and AgB8/4 subunits were identified in all samples analyzed, and an AgB8/2 variant (AgB8/2v8) was found in one bovine sample. The exponentially modified protein abundance index (emPAI) was used to estimate the relative abundance of the AgB subunits, revealing that AgB8/1 subunit was relatively overrepresented in all samples. The abundance of AgB8/3 subunit varied between bovine and human cysts. The oligomeric states formed by E. granulosus AgB and recombinant subunits available, rAgB8/1, rAgB8/2 and rAgB8/3, were characterized by native PAGE, light scattering and microscopy. Recombinant subunits showed markedly distinct oligomerization behaviors, forming oligomers with a maximum size relation of rAgB8/3>rAgB8/2>rAgB8/1. Moreover, the oligomeric states formed by rAgB8/3 subunit were more similar to those observed for AgB purified from hydatid fluid. Pressure-induced dissociation experiments demonstrated that the molecular assemblies formed by the more aggregative subunits, rAgB8/2 and rAgB8/3, also display higher structural stability. Conclusions/Significance For the first time, AgB subunit composition was analyzed in samples from single hydatid cysts, revealing qualitative and quantitative differences between samples. We showed that AgB oligomers are formed by different subunits, which have distinct abundances and oligomerization properties. Overall, our findings have significantly contributed to increase the

  1. USE OF COMBUSTION SYNTHESIS IN PREPARING CERAMIC-MATRIX AND METAL-MATRIX COMPOSITE POWDERS

    SciTech Connect

    Weil, K. Scott; Hardy, John S.

    2005-03-01

    A standard combustion-based approach typically used to synthesize nanosize oxide powders has been modified to prepare composite oxide-metal powders for subsequent densification via sintering or hot-pressing into ceramic- or metal-matrix composites. Copper and cerium nitrate salts were dissolved in the appropriate ratio in water and combined with glycine, then heated to cause autoignition. The ratio of glycine-to-total nitrate concentration was found to have the largest effect on the composition, agglomerate size, crystallite size, and dispersivity of phases in the powder product. After consolidation and sintering under reducing conditions, the resulting composite compact consists of a well-dispersed mixture of sub-micron size reinforcement particles in a fine-grained matrix.

  2. Shrinking mechanism of a porous collagen matrix immersed in solution.

    PubMed

    Chen, Po-Yang; Hsieh, Hsyue-Jen; Huang, Lynn L H

    2014-12-01

    The porous structure of collagen-based matrices enables the infiltration of cells both in in vitro and clinical applications. Reconstituted porous collagen matrices often collapse when they are in contact with aqueous solutions; however, the mechanism for the collapse of the pores is not understood. We, therefore, investigated the interactions between the collagen matrix and different solutions, and discuss the mechanisms for the change in microstructure of the matrix on immersing it in solution. When a dried collagen matrix was immersed in aqueous solutions, the matrix shrunk and pores close to the surface closed. The shrinkage ratio and thickness of the compact microstructure close to the superficial area decreased with increasing ethanol content in the solution. The original porous structure of the collagen matrix was preserved when the matrix was immersed in absolute ethanol. The shrinkage of a porous collagen matrix in contact with aqueous solutions was attributed to the liquid/gas interfacial tension. The average pore diameter of the matrix also significantly affected the shrinkage of the matrix. The shrinkage of the matrix, explained using the Young-Laplace equation, was found to result from the pressure drop, and especially in the pores located superficially, leading to the collapse of the matrix microstructure. The integrity of the porous microstructure allows better penetration of cells in medical applications. The numbers of NIH/3T3 fibroblasts penetrated through the hydrated Col/PBS porous collagen matrices pre-immersed in absolute ethanol with subsequent water and DMEM culture medium replacements were significantly higher than those through matrices hydrated directly in DMEM.

  3. Compact Fuel Element Environment Test

    NASA Technical Reports Server (NTRS)

    Bradley, D. E.; Mireles, O. R.; Hickman, R. R.; Broadway, J. W.

    2012-01-01

    Deep space missions with large payloads require high specific impulse (I(sub sp)) and relatively high thrust to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average I(sub sp). Nuclear thermal rockets (NTRs) capable of high I(sub sp) thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3,000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements that employ high melting point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high-temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via noncontact radio frequency heating and expose samples to hydrogen for typical mission durations has been developed to assist in optimal material and manufacturing process selection without employing fissile material. This Technical Memorandum details the test bed design and results of testing conducted to date.

  4. NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit I sequences compared for members of the genus Taenia (Cestoda).

    PubMed

    Gasser, R B; Zhu, X; McManus, D P

    1999-12-01

    Nine members of the genus Taenia (Taenia taeniaeformis, Taenia hydatigena, Taenia pisiformis, Taenia ovis, Taenia multiceps, Taenia serialis, Taenia saginata, Taenia solium and the Asian Taenia) were characterised by their mitochondrial NADH dehydrogenase subunit 1 gene sequences and their genetic relationships were compared with those derived from the cytochrome c oxidase subunit 1 sequence data. The extent of inter-taxon sequence difference in NADH dehydrogenase subunit 1 (approximately 5.9-30.8%) was usually greater than in cytochrome c oxidase subunit 1 (approximately 2.5-18%). Although topology of the phenograms derived from NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit 1 sequence data differed, there was concordance in that T. multiceps, T. serialis (of canids), T. saginata and the Asian Taenia (of humans) were genetically most similar, and those four members were genetically more similar to T. ovis and T. solium than they were to T. hydatigena and T. pisiformis (of canids) or T. taeniaeformis (of cats). The NADH dehydrogenase subunit 1 sequence data may prove useful in studies of the systematics and population genetic structure of the Taeniidae.

  5. Intranasal immunization with influenza antigens conjugated with cholera toxin subunit B stimulates broad spectrum immunity against influenza viruses.

    PubMed

    Li, Junwei; Arévalo, Maria T; Chen, Yanping; Posadas, Olivia; Smith, Jacob A; Zeng, Mingtao

    2014-01-01

    Frequent mutation of influenza viruses keep vaccinated and non-vaccinated populations vulnerable to new infections, causing serious burdens to public health and the economy. Vaccination with universal influenza vaccines would be the best way to effectively protect people from infection caused by mismatched or unforeseen influenza viruses. Presently, there is no FDA approved universal influenza vaccine. In this study, we expressed and purified a fusion protein comprising of influenza matrix 2 protein ectodomain peptides, a centralized influenza hemagglutinin stem region, and cholera toxin subunit B. Vaccination of BALB/c mice with this novel artificial antigen resulted in potent humoral immune responses, including induction of specific IgA and IgG, and broad protection against infection by multiple influenza viruses. Furthermore, our results demonstrated that when used as a mucosal antigen, cholera toxin subunit B improved antigen-stimulated T cell and memory B cell responses.

  6. Hybrid matrix amplifier

    DOEpatents

    Martens, J.S.; Hietala, V.M.; Plut, T.A.

    1995-01-03

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N[times]M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise. 6 figures.

  7. Hybrid matrix amplifier

    DOEpatents

    Martens, Jon S.; Hietala, Vincent M.; Plut, Thomas A.

    1995-01-01

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N.times.M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise.

  8. Faces of matrix models

    NASA Astrophysics Data System (ADS)

    Morozov, A.

    2012-08-01

    Partition functions of eigenvalue matrix models possess a number of very different descriptions: as matrix integrals, as solutions to linear and nonlinear equations, as τ-functions of integrable hierarchies and as special-geometry prepotentials, as result of the action of W-operators and of various recursions on elementary input data, as gluing of certain elementary building blocks. All this explains the central role of such matrix models in modern mathematical physics: they provide the basic "special functions" to express the answers and relations between them, and they serve as a dream model of what one should try to achieve in any other field.

  9. Database on the structure of large ribosomal subunit RNA.

    PubMed Central

    De Rijk, P; Van de Peer, Y; Chapelle, S; De Wachter, R

    1994-01-01

    A database on large ribosomal subunit RNA is made available. It contains 258 sequences. It provides sequence, alignment and secondary structure information in computer-readable formats. Files can be obtained using ftp. PMID:7524023

  10. The eukaryotic RNA exosome: same scaffold but variable catalytic subunits.

    PubMed

    Lykke-Andersen, Søren; Tomecki, Rafal; Jensen, Torben Heick; Dziembowski, Andrzej

    2011-01-01

    The RNA exosome is a versatile ribonucleolytic protein complex that participates in a multitude of cellular RNA processing and degradation events. It consists of an invariable nine-subunit core that associates with a variety of enzymatically active subunits and co-factors. These contribute to or even provide the catalytic activity and substrate specificity of the complex. The S. cerevisiae exosome has been intensively studied since its discovery in 1997 and thus serves as the archetype of eukaryotic exosomes. Notably, its catalytic potential, derived exclusively from associated subunits, differs between the nuclear and cytoplasmic versions of the complex. The same holds true for other eukaryotes, however, recent discoveries from various laboratories including our own have revealed that there are variations on this theme. Here, we review the latest findings concerning catalytic subunits of eukaryotic exosomes, and we discuss the apparent need for differential composition and subcellular distribution of exosome variants.

  11. Genetic Analysis of the Cytoplasmic Dynein Subunit Families

    PubMed Central

    Pfister, K. Kevin; Shah, Paresh R; Hummerich, Holger; Russ, Andreas; Cotton, James; Annuar, Azlina Ahmad; King, Stephen M; Fisher, Elizabeth M. C

    2006-01-01

    Cytoplasmic dyneins, the principal microtubule minus-end-directed motor proteins of the cell, are involved in many essential cellular processes. The major form of this enzyme is a complex of at least six protein subunits, and in mammals all but one of the subunits are encoded by at least two genes. Here we review current knowledge concerning the subunits, their interactions, and their functional roles as derived from biochemical and genetic analyses. We also carried out extensive database searches to look for new genes and to clarify anomalies in the databases. Our analysis documents evolutionary relationships among the dynein subunits of mammals and other model organisms, and sheds new light on the role of this diverse group of proteins, highlighting the existence of two cytoplasmic dynein complexes with distinct cellular roles. PMID:16440056

  12. A process yields large quantities of pure ribosome subunits

    NASA Technical Reports Server (NTRS)

    Friedman, M.; Lu, P.; Rich, A.

    1972-01-01

    Development of process for in-vitro protein synthesis from living cells followed by dissociation of ribosomes into subunits is discussed. Process depends on dialysis or use of chelating agents. Operation of process and advantages over previous methods are outlined.

  13. Pesticide-Exposure Matrix

    Cancer.gov

    The "Pesticide-exposure Matrix" was developed to help epidemiologists and other researchers identify the active ingredients to which people were likely exposed when their homes and gardens were treated for pests in past years.

  14. In vitro and in vivo evaluation of a bondable compact for the prolonged delivery of triamcinolone acetonide to the oral cavity in patients with lichen planus.

    PubMed

    Deasy, P B; Collins, A E; Burke, F M; Shanley, D B

    1989-01-01

    Compacts weighing 40 mg and containing triamcinolone acetonide 70-90% and polyhydroxybutyric acid (PHB) 30-10% or poly (DL-lactic acid) 20% with a diameter of 5 mm were bonded onto the side-wall of molar teeth. In vitro dissolution studies showed the compacts to release 12% of drug in 30 days with an initial burst effect. Drug loading or polymer matrix type had little effect. In vivo studies in dogs showed that compacts containing 80% drug in PHB produced salivary levels of triamcinolone acetonide for 30 days. When evaluated in five patients with lichen planus resistant to conventional therapy, these compacts produce a slight clinical improvement in three subjects. Differential scanning calorimetry studies confirmed that the drug and polymer were present as a physical mix in these compacts.

  15. Subunit-Specific Trafficking of GABAA Receptors during Status Epilepticus

    PubMed Central

    Goodkin, Howard P.; Joshi, Suchitra; Mtchedlishvili, Zakaria; Brar, Jasmit; Kapur, Jaideep

    2010-01-01

    It is proposed that a reduced surface expression of GABAA receptors (GABARs) contributes to the pathogenesis of status epilepticus (SE), a condition characterized by prolonged seizures. This hypothesis was based on the finding that prolonged epileptiform bursting (repetitive bursts of prolonged depolarizations with superimposed action potentials) in cultures of dissociated hippocampal pyramidal neurons (dissociated cultures) results in the increased intracellular accumulation of GABARs. However, it is not known whether this rapid modification in the surface-expressed GABAR pool results from selective, subunit-dependent or nonselective, subunit-independent internalization of GABARs. In hippocampal slices obtained from animals undergoing prolonged SE (SE-treated slices), we found that the surface expression of the GABARβ2/3 and γ2 subunits was reduced, whereas that of the δ subunit was not. Complementary electrophysiological recordings from dentate granule cells in SE-treated slices demonstrated a reduction in GABAR-mediated synaptic inhibition, but not tonic inhibition. A reduction in the surface expression of the γ2 subunit, but not the δ subunit was also observed in dissociated cultures and organotypic hippocampal slice cultures when incubated in an elevated KCl external medium or an elevated KCl external medium supplemented with NMDA, respectively. Additional studies demonstrated that the reduction in the surface expression of the γ2 subunit was independent of direct ligand binding of the GABAR. These findings demonstrate that the regulation of surface-expressed GABAR pool during SE is subunit-specific and occurs independent of ligand binding. The differential modulation of the surface expression of GABARs during SE has potential implications for the treatment of this neurological emergency. PMID:18322097

  16. F-subunit reinforces torque generation in V-ATPase.

    PubMed

    Kishikawa, Jun-ichi; Seino, Akihiko; Nakanishi, Atsuko; Tirtom, Naciye Esma; Noji, Hiroyuki; Yokoyama, Ken; Hayashi, Kumiko

    2014-09-01

    Vacuolar-type H(+)-pumping ATPases (V-ATPases) perform remarkably diverse functions in eukaryotic organisms. They are present in the membranes of many organelles and regulate the pH of several intracellular compartments. A family of V-ATPases is also present in the plasma membranes of some bacteria. Such V-ATPases function as ATP-synthases. Each V-ATPase is composed of a water-soluble domain (V1) and a membrane-embedded domain (Vo). The ATP-driven rotary unit, V[Formula: see text], is composed of A, B, D, and F subunits. The rotary shaft (the DF subcomplex) rotates in the central cavity of the A3B3-ring (the catalytic hexamer ring). The D-subunit, which has a coiled-coil domain, penetrates into the ring, while the F-subunit is a globular-shaped domain protruding from the ring. The minimal ATP-driven rotary unit of V[Formula: see text] is comprised of the A3B3D subunits, and we therefore investigated how the absence of the globular-shaped F-subunit affects the rotary torque generation of V[Formula: see text]. Using a single-molecule technique, we observed the motion of the rotary motors. To obtain the torque values, we then analyzed the measured motion trajectories based on the fluctuation theorem, which states that the law of entropy production in non-equilibrium conditions and has been suggested as a novel and effective method for measuring torque. The measured torque of A3B3D was half that of the wild-type V1, and full torque was recovered in the mutant V1, in which the F-subunit was genetically fused with the D-subunit, indicating that the globular-shaped F-subunit reinforces torque generation in V1.

  17. Functional Polymer Matrix Fibers

    DTIC Science & Technology

    2007-11-02

    the carbon nanofibers led to the deterioration of the polymeric cellulose structure. Extensive research on the surface treatment of carbon nanofibers...1 November 2003 - 14-Mar-05 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER FA8655-03-1-3042 Functional Polymer Matrix Fibres 5b. GRANT NUMBER 5c. PROGRAM...MARYLABONE RD LONDON NWl 5TH PERFORMANCE REPORT Project title: Functional polymer matrix fibers Period of performance: 1 November 2003 - 31 October 2004

  18. Horizontal membrane-intrinsic α-helices in the stator a-subunit of an F-type ATP synthase.

    PubMed

    Allegretti, Matteo; Klusch, Niklas; Mills, Deryck J; Vonck, Janet; Kühlbrandt, Werner; Davies, Karen M

    2015-05-14

    ATP, the universal energy currency of cells, is produced by F-type ATP synthases, which are ancient, membrane-bound nanomachines. F-type ATP synthases use the energy of a transmembrane electrochemical gradient to generate ATP by rotary catalysis. Protons moving across the membrane drive a rotor ring composed of 8-15 c-subunits. A central stalk transmits the rotation of the c-ring to the catalytic F1 head, where a series of conformational changes results in ATP synthesis. A key unresolved question in this fundamental process is how protons pass through the membrane to drive ATP production. Mitochondrial ATP synthases form V-shaped homodimers in cristae membranes. Here we report the structure of a native and active mitochondrial ATP synthase dimer, determined by single-particle electron cryomicroscopy at 6.2 Å resolution. Our structure shows four long, horizontal membrane-intrinsic α-helices in the a-subunit, arranged in two hairpins at an angle of approximately 70° relative to the c-ring helices. It has been proposed that a strictly conserved membrane-embedded arginine in the a-subunit couples proton translocation to c-ring rotation. A fit of the conserved carboxy-terminal a-subunit sequence places the conserved arginine next to a proton-binding c-subunit glutamate. The map shows a slanting solvent-accessible channel that extends from the mitochondrial matrix to the conserved arginine. Another hydrophilic cavity on the lumenal membrane surface defines a direct route for the protons to an essential histidine-glutamate pair. Our results provide unique new insights into the structure and function of rotary ATP synthases and explain how ATP production is coupled to proton translocation.

  19. Composite Matrix Experimental Combustor

    DTIC Science & Technology

    1994-04-01

    Preliminary (Macro) Combustor Design ............................. 28 4.1 Preliminary Design Study-Early Concept Combustion System ............. 28 4.2...provided in Appendix B. 4.1 PRELIMINARY DESIGN STUDY-EARLY CONCEPT COMBUSTION SYSTEM The preliminary design effort resulted in the selection of the early...overall flowpath. The concept I combustor is a compact, annular, reverse-flow design incorporating a single row of primary combustion air holes and a

  20. Optical coherency matrix tomography

    PubMed Central

    Kagalwala, Kumel H.; Kondakci, H. Esat; Abouraddy, Ayman F.; Saleh, Bahaa E. A.

    2015-01-01

    The coherence of an optical beam having multiple degrees of freedom (DoFs) is described by a coherency matrix G spanning these DoFs. This optical coherency matrix has not been measured in its entirety to date—even in the simplest case of two binary DoFs where G is a 4 × 4 matrix. We establish a methodical yet versatile approach—optical coherency matrix tomography—for reconstructing G that exploits the analogy between this problem in classical optics and that of tomographically reconstructing the density matrix associated with multipartite quantum states in quantum information science. Here G is reconstructed from a minimal set of linearly independent measurements, each a cascade of projective measurements for each DoF. We report the first experimental measurements of the 4 × 4 coherency matrix G associated with an electromagnetic beam in which polarization and a spatial DoF are relevant, ranging from the traditional two-point Young’s double slit to spatial parity and orbital angular momentum modes. PMID:26478452

  1. Transcription Activator Interactions with Multiple SWI/SNF Subunits

    PubMed Central

    Neely, Kristen E.; Hassan, Ahmed H.; Brown, Christine E.; Howe, LeAnn; Workman, Jerry L.

    2002-01-01

    We have previously shown that the yeast SWI/SNF complex stimulates in vitro transcription from chromatin templates in an ATP-dependent manner. SWI/SNF function in this regard requires the presence of an activator with which it can interact directly, linking activator recruitment of SWI/SNF to transcriptional stimulation. In this study, we determine the SWI/SNF subunits that mediate its interaction with activators. Using a photo-cross-linking label transfer strategy, we show that the Snf5, Swi1, and Swi2/Snf2 subunits are contacted by the yeast acidic activators, Gcn4 and Hap4, in the context of the intact native SWI/SNF complex. In addition, we show that the same three subunits can interact individually with acidic activation domains, indicating that each subunit contributes to binding activators. Furthermore, mutations that reduce the activation potential of these activators also diminish its interaction with each of these SWI/SNF subunits. Thus, three distinct subunits of the SWI/SNF complex contribute to its interactions with activation domains. PMID:11865042

  2. Transcriptional regulators of Na,K-ATPase subunits

    PubMed Central

    Li, Zhiqin; Langhans, Sigrid A.

    2015-01-01

    The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic α-subunit, the β-subunit and the FXYD proteins, are controlled extensively during development and to accommodate physiological needs. The spatial and temporal expression of Na,K-ATPase is partially regulated at the transcriptional level. Numerous transcription factors, hormones, growth factors, lipids, and extracellular stimuli modulate the transcription of the Na,K-ATPase subunits. Moreover, epigenetic mechanisms also contribute to the regulation of Na,K-ATPase expression. With the ever growing knowledge about diseases associated with the malfunction of Na,K-ATPase, this review aims at summarizing the best-characterized transcription regulators that modulate Na,K-ATPase subunit levels. As abnormal expression of Na,K-ATPase subunits has been observed in many carcinoma, we will also discuss transcription factors that are associated with epithelial-mesenchymal transition, a crucial step in the progression of many tumors to malignant disease. PMID:26579519

  3. Diagnostics of soil compaction in steppe zone

    NASA Astrophysics Data System (ADS)

    Sorokin, Alexey; Kust, German

    2014-05-01

    Land degradation and desertification are among the major challenges in steppe zone, and leads the risks of food security in affected areas. Soil compaction is one of the basic reasons of degradation of arable land. The processes of soil compaction have different genesis. Knowledge of soil compaction mechanisms and their early diagnostics permit to accurately forecast velocity and degree of degradation processes as well as to undertake effective preventive measures and land reclamation activities. Manifestations of soil compaction and degradation of soil structure due to vertic, alkaline and and mechanical (agro-) compaction, as well as caused by combination of these processes in irrigated and rainfed conditions were studied in four model plots in Krasnodar and Saratov regions of Russia. Typic chernozems, solonetz and kashtanozem solonetz, south chernozem and dark-kashtanozem soils were under investigation. Morphological (mesomorphological, micromorphological and microtomographic) features, as well as number of physical (particle size analyses, water-peptizable clays content (WPC), swelling and shrinking, bulk density and moisture), chemical (humus, pH, CAC, EC), and mineralogical (clay fraction) properties were investigated. Method for grouping soil compaction types by morphological features was proposed. It was shown that: - overcompacted chernozems with vertic features has porosity close to natural chernozems (about 40%), but they had the least pore diameter (7-12 micron) among studied soils. Solonetzic soils had the least amount of "pore-opening" (9%). - irrigation did not lead to the degradation of soil structure on micro-level. - "mechanically" (agro-) compacted soils retained an intra-aggregate porosity. - studied soils are characterized by medium and heavy particle size content (silt [<0.1mm] of 30-60%). Subsoil horizons of chernozems with vertic and alkaline features were the heaviest by particle size content. - the share of WPC to clay ratio was 40% in

  4. 78 FR 20355 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ... this session of the Council should notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr... (502) 581-1234. FOR FURTHER INFORMATION CONTACT: Inquiries may be addressed to Mr. Gary S. Barron, FBI...-2803, facsimile (304) 625-2868. Dated: March 26, 2013. Gary S. Barron, FBI Compact Officer,...

  5. 77 FR 60475 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... address this session of the Council should notify the Federal Bureau Of Investigation (FBI) Compact..., FBI Compact Officer, Module D3, 1000 Custer Hollow Road, Clarksburg, West Virginia 26306, telephone (304) 625-2803, facsimile (304) 625-2868. Dated: September 19, 2012. Gary S. Barron, FBI...

  6. 78 FR 61384 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... Council should notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr. Gary S. Barron at... (813) 289- 8200. FOR FURTHER INFORMATION CONTACT: Inquiries may be addressed to Mr. Gary S. Barron, FBI...-2803, facsimile (304) 625-2868. Dated: September 25, 2013. Gary S. Barron, FBI Compact...

  7. Soil Compaction Investigation. Report No. 3: Compaction Studies on Sand Subgrade

    DTIC Science & Technology

    1949-10-01

    TRACKING After Com.J2actlon ~Dr~) After Com:12action ~Wet) After Grading Prior to Com11action Water Dry Water Dry Water Dry Compaction Number of...Water Dry Water Dry Depth Content Density , Depth Content Density , Ft ; Lb/CuFt Cam;paction Ft ! Lb/CuFt Compaction Before SoeJ.d.ns 5-Min Soaking

  8. COMPACT PROTON INJECTOR AND FIRST ACCELERATOR SYSTEM TEST FOR COMPACT PROTON DIELECTRIC WALL CANCER THERAPY ACCELERATOR

    SciTech Connect

    Chen, Y; Guethlein, G; Caporaso, G; Sampayan, S; Blackfield, D; Cook, E; Falabella, S; Harris, J; Hawkins, S; Nelson, S; Poole, B; Richardson, R; Watson, J; Weir, J; Pearson, D

    2009-04-23

    A compact proton accelerator for cancer treatment is being developed by using the high-gradient dielectric insulator wall (DWA) technology [1-4]. We are testing all the essential DWA components, including a compact proton source, on the First Article System Test (FAST). The configuration and progress on the injector and FAST will be presented.

  9. MMP-7 cleaves the NR1 NMDA receptor subunit and modifies NMDA receptor function

    PubMed Central

    Szklarczyk, Arek; Ewaleifoh, Osefame; Beique, Jean-Claude; Wang, Yue; Knorr, David; Haughey, Norman; Malpica, Tanya; Mattson, Mark P.; Huganir, Richard; Conant, Katherine

    2008-01-01

    Matrix metalloproteinases (MMPs) are zinc-dependent enzymes that play a role in the inflammatory response. These enzymes have been well studied in the context of cancer biology and inflammation. Recent studies, however, suggest that these enzymes also play roles in brain development and neurodegenerative disease. Select MMPs can target proteins critical to synaptic structure and neuronal survival, including integrins and cadherins. Here, we show that one member of the MMP family, MMP-7, which may be released from cells, including microglia, can target a protein critical to synaptic function. Through analysis of extracts from murine cortical slice preparations, we show that MMP-7 cleaves the NR1 subunit of the N-methyl-d-aspartate (NMDA) receptor to generate an N-terminal fragment of ∼65 kDa. Moreover, studies with recombinant protein show that MMP-7-mediated cleavage of NR1 occurs at amino acid 517, which is extracellular and just distal to the first transmembrane domain. Data suggest that NR2A, which shares sequence homology with NR1, is also cleaved following treatment of slices with MMP-7, while select AMPA receptor subunits are not. Consistent with a potential effect of MMP-7 on ligand binding, additional experiments demonstrate that NMDA-mediated calcium flux is significantly diminished by MMP-7 pretreatment of cultures. In addition, the AMPA/NMDA ratio is increased by MMP-7 pretreatment. These data suggest that synaptic function may be altered in neurological conditions associated with increased levels of MMP-7.—Szklarczyk, A., Ewaleifoh, O., Beique, J.-C., Wang, Y., Knorr, D., Haughey, N., Malpica, T., Mattson, M. P., Huganir, R., Conant, K. MMP-7 cleaves the NR1 NMDA receptor subunit and modifies NMDA receptor function. PMID:18644839

  10. Expression and functional analysis of a cytoplasmic domain variant of the beta 1 integrin subunit.

    PubMed

    Balzac, F; Belkin, A M; Koteliansky, V E; Balabanov, Y V; Altruda, F; Silengo, L; Tarone, G

    1993-04-01

    We have previously described a variant form of the integrin beta 1 subunit (beta 1B)1 characterized by an altered sequence at the cytoplasmic domain. Using polyclonal antibodies to a synthetic peptide corresponding to the unique sequence of the beta 1B, we analyzed the expression of this molecule in human tissues and cultured cells. Western blot analysis showed that the beta 1B is expressed in skin and liver and, in lower amounts, in skeletal and cardiac muscles. The protein was not detectable in brain, kidney, and smooth muscle. In vitro cultured keratinocytes and hepatoma cells are positive, but fibroblasts, endothelial cells, and smooth muscle cells are negative. An astrocytoma cell line derived from immortalized fetal astrocytes was found to express beta 1B. In these cells beta 1B represent integral of 30% of the beta 1 and form heterodimers with alpha 1 and alpha 5 subunits. To investigate the functional properties of beta 1B, the full-length cDNA coding for this molecule was transfected into CHO cells. Stable transfectants were selected and the beta 1B was identified by a mAb that discriminate between the transfected human protein and the endogenous hamster beta 1A. Immunoprecipitation experiments indicated that the beta 1B was exported at the cell surface in association with the endogenous hamster alpha subunits. The alpha 5/beta 1B complex bound to a fibronectin-affinity matrix and was specifically released by RGD-containing peptides. Thus beta 1B and beta 1A are similar as far as the alpha/beta association and fibronectin binding are concerned. The two proteins differ, however, in their subcellular localization. Immunofluorescence studies indicated, in fact, that beta 1B, in contrast to beta 1A, does not localize in focal adhesions. The restricted tissue distribution and the distinct subcellular localization, suggest that beta 1B has unique functional properties.

  11. Expression and functional analysis of a cytoplasmic domain variant of the beta 1 integrin subunit

    PubMed Central

    1993-01-01

    We have previously described a variant form of the integrin beta 1 subunit (beta 1B)1 characterized by an altered sequence at the cytoplasmic domain. Using polyclonal antibodies to a synthetic peptide corresponding to the unique sequence of the beta 1B, we analyzed the expression of this molecule in human tissues and cultured cells. Western blot analysis showed that the beta 1B is expressed in skin and liver and, in lower amounts, in skeletal and cardiac muscles. The protein was not detectable in brain, kidney, and smooth muscle. In vitro cultured keratinocytes and hepatoma cells are positive, but fibroblasts, endothelial cells, and smooth muscle cells are negative. An astrocytoma cell line derived from immortalized fetal astrocytes was found to express beta 1B. In these cells beta 1B represent integral of 30% of the beta 1 and form heterodimers with alpha 1 and alpha 5 subunits. To investigate the functional properties of beta 1B, the full- length cDNA coding for this molecule was transfected into CHO cells. Stable transfectants were selected and the beta 1B was identified by a mAb that discriminate between the transfected human protein and the endogenous hamster beta 1A. Immunoprecipitation experiments indicated that the beta 1B was exported at the cell surface in association with the endogenous hamster alpha subunits. The alpha 5/beta 1B complex bound to a fibronectin-affinity matrix and was specifically released by RGD-containing peptides. Thus beta 1B and beta 1A are similar as far as the alpha/beta association and fibronectin binding are concerned. The two proteins differ, however, in their subcellular localization. Immunofluorescence studies indicated, in fact, that beta 1B, in contrast to beta 1A, does not localize in focal adhesions. The restricted tissue distribution and the distinct subcellular localization, suggest that beta 1B has unique functional properties. PMID:7681433

  12. DNA compaction by azobenzene-containing surfactant

    SciTech Connect

    Zakrevskyy, Yuriy; Kopyshev, Alexey; Lomadze, Nino; Santer, Svetlana

    2011-08-15

    We report on the interaction of cationic azobenzene-containing surfactant with DNA investigated by absorption and fluorescence spectroscopy, dynamic light scattering, and atomic force microscopy. The properties of the surfactant can be controlled with light by reversible switching of the azobenzene unit, incorporated into the surfactant tail, between a hydrophobic trans (visible irradiation) and a hydrophilic cis (UV irradiation) configuration. The influence of the trans-cis isomerization of the azobenzene on the compaction process of DNA molecules and the role of both isomers in the formation and colloidal stability of DNA-surfactant complexes is discussed. It is shown that the trans isomer plays a major role in the DNA compaction process. The influence of the cis isomer on the DNA coil configuration is rather small. The construction of a phase diagram of the DNA concentration versus surfactant/DNA charge ratio allows distancing between three major phases: colloidally stable and unstable compacted globules, and extended coil conformation. There is a critical concentration of DNA above which the compacted globules can be hindered from aggregation and precipitation by adding an appropriate amount of the surfactant in the trans configuration. This is because of the compensation of hydrophobicity of the globules with an increasing amount of the surfactant. Below the critical DNA concentration, the compacted globules are colloidally stable and can be reversibly transferred with light to an extended coil state.

  13. Strategy Guideline: Compact Air Distribution Systems

    SciTech Connect

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  14. Counterintuitive compaction behavior of clopidogrel bisulfate polymorphs.

    PubMed

    Khomane, Kailas S; More, Parth K; Bansal, Arvind K

    2012-07-01

    Being a density violator, clopidogrel bisulfate (CLP) polymorphic system (forms I and II) allows us to study individually the impact of molecular packing (true density) and thermodynamic properties such as heat of fusion on the compaction behavior. These two polymorphs of CLP were investigated for in-die and out-of-die compaction behavior using CTC profile, Heckel, and Walker equations. Compaction studies were performed on a fully instrumented rotary tabletting machine. Detailed examinations of the molecular packing of each form revealed that arrangement of the sulfate anion differs significantly in both crystal forms, thus conferring different compaction behavior to two forms. Close cluster packing of molecules in form I offers a rigid structure, which has poor compressibility and hence resists deformation under compaction pressure. This results into lower densification, higher yield strength, and mean yield pressure, as compared with form II at a given pressure. However, by virtue of higher bonding strength, form I showed superior tabletability, despite its poor compressibility and deformation behavior. Form I, having higher true density and lower heat of fusion showed higher bonding strength. Hence, true density and not heat of fusion can be considered predictor of bonding strength of the pharmaceutical powders.

  15. Ultra-Compact Motor Controller

    NASA Technical Reports Server (NTRS)

    Townsend, William T.; Crowell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

    2012-01-01

    knowledge by each motor controller of the state of all the motors in the system at 500 Hz also allows parallel processing of higher-level kinematic matrix calculations.

  16. 77 FR 22805 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ..., concerning the date and location of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). The document listed... Privacy Compact; Correction AGENCY: Federal Bureau of Investigation. ACTION: Notice; Correction....

  17. Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments

    SciTech Connect

    Nihei, K.T.; Nakagawa, S.; Reverdy, F.; Meyer, L.R.; Duranti, L.; Ball, G.

    2010-12-15

    Sediments undergoing compaction typically exhibit transversely isotropic (TI) elastic properties. We present a new experimental apparatus, the phased array compaction cell, for measuring the TI elastic properties of clay-rich sediments during compaction. This apparatus uses matched sets of P- and S-wave ultrasonic transducers located along the sides of the sample and an ultrasonic P-wave phased array source, together with a miniature P-wave receiver on the top and bottom ends of the sample. The phased array measurements are used to form plane P-waves that provide estimates of the phase velocities over a range of angles. From these measurements, the five TI elastic constants can be recovered as the sediment is compacted, without the need for sample unloading, recoring, or reorienting. This paper provides descriptions of the apparatus, the data processing, and an application demonstrating recovery of the evolving TI properties of a compacting marine sediment sample.

  18. Investigation of the Capability of Compact Polarimetric SAR Interferometry to Estimate Forest Height

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Xie, Lei; Wang, Chao; Chen, Jiehong

    2013-08-01

    The main objective of this paper is to investigate the capability of compact Polarimetric SAR Interferometry (C-PolInSAR) on forest height estimation. For this, the pseudo fully polarimetric interferomteric (F-PolInSAR) covariance matrix is firstly reconstructed, then the three- stage inversion algorithm, hybrid algorithm, Music and Capon algorithm are applied to both C-PolInSAR covariance matrix and pseudo F-PolInSAR covariance matrix. The availability of forest height estimation is demonstrated using L-band data generated by simulator PolSARProSim and X-band airborne data acquired by East China Research Institute of Electronic Engineering, China Electronics Technology Group Corporation.

  19. Effect of the Compaction Pressure and Ni Content on the Modified Aluminum-Based Perovskite Synthesis Designed to Immobilize the Radioactive Waste in Combustion Mode

    NASA Astrophysics Data System (ADS)

    Tarasova, E. S.; Dolmatov, O. Yu; Isachenko, D. S.; Permikin, A. A.; Semenov, A. O.

    2016-06-01

    The article deals with the synthesis of perovskite-like ceramics matrix material for immobilization of radioactive waste by SHS method. The dependence of the compaction pressure on the synthesis of the samples was established. Synthesis conditions for the matrix with the desired properties of the composition were determined that is acceptable for reliable isolation of radionuclides throughout the long-term storage of waste. The maximum amount of aluminum perovskite is observed when the initial mixture compaction pressure equal to 30 MPa and 25% wt. Nickel.

  20. Activation analysis of the compact ignition tokamak

    SciTech Connect

    Selcow, E.C.

    1986-01-01

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak.

  1. Lacunary Fourier Series for Compact Quantum Groups

    NASA Astrophysics Data System (ADS)

    Wang, Simeng

    2017-02-01

    This paper is devoted to the study of Sidon sets, {Λ(p)}-sets and some related notions for compact quantum groups. We establish several different characterizations of Sidon sets, and in particular prove that any Sidon set in a discrete group is a strong Sidon set in the sense of Picardello. We give several relations between Sidon sets, {Λ(p)}-sets and lacunarities for L p -Fourier multipliers, generalizing a previous work by Blendek and Michalic̆ek. We also prove the existence of {Λ(p)}-sets for orthogonal systems in noncommutative L p -spaces, and deduce the corresponding properties for compact quantum groups. Central Sidon sets are also discussed, and it turns out that the compact quantum groups with the same fusion rules and the same dimension functions have identical central Sidon sets. Several examples are also included.

  2. Impacts by Compact Ultra Dense Objects

    NASA Astrophysics Data System (ADS)

    Birrell, Jeremey; Labun, Lance; Rafelski, Johann

    2012-03-01

    We propose to search for nuclear density or greater compact ultra dense objects (CUDOs), which could constitute a significant fraction of the dark matter [1]. Considering their high density, the gravitational tidal forces are significant and atomic-density matter cannot stop an impacting CUDO, which punctures the surface of the target body, pulverizing, heating and entraining material near its trajectory through the target [2]. Because impact features endure over geologic timescales, the Earth, Moon, Mars, Mercury and large asteroids are well-suited to act as time-integrating CUDO detectors. There are several potential candidates for CUDO structure such as strangelet fragments or more generally dark matter if mechanisms exist for it to form compact objects. [4pt] [1] B. J. Carr, K. Kohri, Y. Sendouda, & J.'i. Yokoyama, Phys. Rev. D81, 104019 (2010). [0pt] [2] L. Labun, J. Birrell, J. Rafelski, Solar System Signatures of Impacts by Compact Ultra Dense Objects, arXiv:1104.4572.

  3. Compaction dynamics of wet granular packings

    NASA Astrophysics Data System (ADS)

    Vandewalle, Nicolas; Ludewig, Francois; Fiscina, Jorge E.; Lumay, Geoffroy

    2013-03-01

    The extremely slow compaction dynamics of wet granular assemblies has been studied experimentally. The cohesion, due to capillary bridges between neighboring grains, has been tuned using different liquids having specific surface tension values. The characteristic relaxation time for compaction τ grows strongly with cohesion. A kinetic model, based on a free volume kinetic equations and the presence of a capillary energy barrier (due to liquid bridges), is able to reproduce quantitatively the experimental curves. This model allows one to describe the cohesion in wet granular packing. The influence of relative humidity (RH) on the extremely slow compaction dynamics of a granular assembly has also been investigated in the range 20 % - 80 % . Triboelectric and capillary condensation effects have been introduced in the kinetic model. Results confirm the existence of an optimal condition at RH ~ 45 % for minimizing cohesive interactions between glass beads.

  4. Hall MHD Equilibrium of Accelerated Compact Toroids

    NASA Astrophysics Data System (ADS)

    Howard, S. J.; Hwang, D. Q.; Horton, R. D.; Evans, R. W.; Brockington, S. J.

    2007-11-01

    We examine the structure and dynamics of the compact toroid's magnetic field. The compact toroid is dramatically accelerated by a large rail-gun Lorentz force density equal to j xB. We use magnetic data from the Compact Toroid Injection Experiment to answer the question of exactly where in the system j xB has nonzero values, and to what extent we can apply the standard model of force-free equilibrium. In particular we present a method of analysis of the magnetic field probe signals that allows direct comparison to the predictions of the Woltjer-Taylor force-free model and Turner's generalization of magnetic relaxation in the presence of a non-zero Hall term and fluid vorticity.

  5. NMR structure and functional characteristics of the hydrophilic N terminus of the potassium channel beta-subunit Kvbeta1.1.

    PubMed

    Wissmann, R; Baukrowitz, T; Kalbacher, H; Kalbitzer, H R; Ruppersberg, J P; Pongs, O; Antz, C; Fakler, B

    1999-12-10

    Rapid N-type inactivation of voltage-dependent potassium (Kv) channels controls membrane excitability and signal propagation in central neurons and is mediated by protein domains (inactivation gates) occluding the open channel pore from the cytoplasmic side. Inactivation domains (ID) are donated either by the pore-forming alpha-subunit or certain auxiliary beta-subunits. Upon coexpression, Kvbeta1.1 was found to endow non-inactivating members of the Kv1alpha family with fast inactivation via its unique N terminus. Here we investigated structure and functional properties of the Kvbeta1.1 N terminus (amino acids 1-62, betaN-(1-62)) using NMR spectroscopy and patch clamp recordings. betaN-(1-62) showed all hallmarks of N-type inactivation: it inactivated non-inactivating Kv1.1 channels when applied to the cytoplasmic side as a synthetic peptide, and its interaction with the alpha-subunit was competed with tetraethylammonium and displayed an affinity in the lower micromolar range. In aequous and physiological salt solution, betaN-(1-62) showed no well defined three-dimensional structure, it rather existed in a fast equilibrium of multiple weakly structured states. These structural and functional properties of betaN-(1-62) closely resemble those of the "unstructured" ID from Shaker B, but differ markedly from those of the compactly folded ID of the Kv3.4 alpha-subunit.

  6. Hybrid Rubisco of tomato large subunits and tobacco small subunits is functional in tobacco plants.

    PubMed

    Zhang, Xing-Hai; Webb, James; Huang, Yi-Hong; Lin, Li; Tang, Ri-Sheng; Liu, Aimin

    2011-03-01

    Biogenesis of functional ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in plants requires specific assembly in the chloroplast of the imported, cytosol-synthesized small subunits (SS) with the chloroplast-made large subunits (LS). Accumulating evidence indicates that chloroplasts (plastids) generally have a low tolerance for assembling foreign or modified Rubisco. To explore Rubisco engineering, we created two lines of transplastomic tobacco plants whose rbcL gene was replaced by tomato-derived rbcL: plant LLS2 with Rubisco composed of tobacco SS and Q437R LS and plant LLS4 with a hybrid Rubisco of tobacco SS and tomato LS (representing four substitutions of Y226F, A230T, S279T and Q437R from tobacco LS). Plant LLS2 exhibited similar phenotypes as the wild type. Plant LLS4 showed lower chlorophyll and Rubisco levels particularly in young emerging leaves, lower photosynthesis rates and biomass during early stages of development, but was able to reach reproductive maturity and somewhat wild type-like phenotype under ambient CO₂ condition. In vitro assays detected similar carboxylase activity and RuBP affinity in LLS2 and LLS4 plants as in wild type. Our studies demonstrated that tomato LS was sufficiently assembled with tobacco SS into functional Rubisco. The hybrid Rubisco of tomato LS and tobacco SS can drive photosynthesis that supports photoautotrophic growth and reproduction of tobacco plants under ambient CO₂ and light conditions. We discuss the effect of these residue substitutions on Rubisco activity and the possible attribution of chlorophyll deficiency to the in planta photosynthesis performance in the hybrid Rubisco plants.

  7. Explaining compact groups as change alignments

    NASA Technical Reports Server (NTRS)

    Mamon, Gary A.

    1990-01-01

    The physical nature of the apparently densest groups of galaxies, known as compact groups is a topic of some recent controversy, despite the detailed observations of a well-defined catalog of 100 isolated compact groups compiled by Hickson (1982). Whereas many authors have espoused the view that compact groups are bound systems, typically as dense as they appear in projection on the sky (e.g., Williams & Rood 1987; Sulentic 1987; Hickson & Rood 1988), others see them as the result of chance configurations within larger systems, either in 1D (chance alignments: Mamon 1986; Walke & Mamon 1989), or in 3D (transient cores: Rose 1979). As outlined in the companion review to this contribution (Mamon, in these proceedings), the implication of Hickson's compact groups (HCGs) being dense bound systems is that they would then constitute the densest isolated systems of galaxies in the Universe and the privileged site for galaxy interactions. In a previous paper (Mamon 1986), the author reviewed the arguments given for the different theories of compact groups. Since then, a dozen papers have been published on the subject, including a thorough and perceptive review by White (1990), thus more than doubling the amount written on the subject. Here, the author first enumerates the arguments that he brought up in 1986 substantiating the chance alignment hypothesis, then he reviews the current status of the numerous recent arguments arguing against chance alignments and/or for the bound dense group hypothesis (both for the majority of HCGs but not all of them), and finally he reconsiders each one of these anti-chance alignment arguments and shows that, rather than being discredited, the chance alignment hypothesis remains a fully consistent explanation for the nature of compact groups.

  8. Observational properties of compact groups of galaxies

    NASA Technical Reports Server (NTRS)

    Hickson, Paul

    1990-01-01

    Compact groups are small, relatively isolated, systems of galaxies with projected separations comparable to the diameters of the galaxies themselves. Two well-known examples are Stephan's Quintet (Stephan, 1877) and Seyfert's Sextet (Seyfert 1948a,b). In groups such as these, the apparent space density of galaxies approaches 10(exp 6) Mpc(sub -3), denser even than the cores of rich clusters. The apparent unlikeliness of the chance occurrence of such tight groupings lead Ambartsumyan (1958, 1975) to conclude that compact groups must be physically dense systems. This view is supported by clear signs of galaxy interactions that are seen in many groups. Spectroscopic observations reveal that typical relative velocities of galaxies in the groups are comparable to their internal stellar velocities. This should be conducive to strong gravitational interactions - more so than in rich clusters, where galaxy velocities are typically much higher. This suggests that compact groups could be excellent laboratories in which to study galaxy interactions and their effects. Compact groups often contain one or more galaxies whose redshift differs greatly from those of the other group members. If these galaxies are at the same distance as the other members, either entire galaxies are being ejected at high velocities from these groups, or some new physical phenomena must be occurring. If their redshifts are cosmological, we must explain why so many discordant galaxies are found in compact groups. In recent years much progress has been made in addressing these questions. Here, the author discusses the current observational data on compact groups and their implications.

  9. Portable compact cold atoms clock topology

    NASA Astrophysics Data System (ADS)

    Pechoneri, R. D.; Müller, S. T.; Bueno, C.; Bagnato, V. S.; Magalhães, D. V.

    2016-07-01

    The compact frequency standard under development at USP Sao Carlos is a cold atoms system that works with a distributed hardware system principle and temporal configuration of the interrogation method of the atomic sample, in which the different operation steps happen in one place: inside the microwave cavity. This type of operation allows us to design a standard much more compact than a conventional one, where different interactions occur in the same region of the apparatus. In this sense, it is necessary to redefine all the instrumentation associated with the experiment. This work gives an overview of the topology we are adopting for the new system.

  10. Remote vacuum compaction of compressible hazardous waste

    DOEpatents

    Coyne, Martin J.; Fiscus, Gregory M.; Sammel, Alfred G.

    1998-01-01

    A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

  11. Compact Focal Plane Assembly for Planetary Science

    NASA Technical Reports Server (NTRS)

    Brown, Ari; Aslam, Shahid; Huang, Wei-Chung; Steptoe-Jackson, Rosalind

    2013-01-01

    A compact radiometric focal plane assembly (FPA) has been designed in which the filters are individually co-registered over compact thermopile pixels. This allows for construction of an ultralightweight and compact radiometric instrument. The FPA also incorporates micromachined baffles in order to mitigate crosstalk and low-pass filter windows in order to eliminate high-frequency radiation. Compact metal mesh bandpass filters were fabricated for the far infrared (FIR) spectral range (17 to 100 microns), a game-changing technology for future planetary FIR instruments. This fabrication approach allows the dimensions of individual metal mesh filters to be tailored with better than 10- micron precision. In contrast, conventional compact filters employed in recent missions and in near-term instruments consist of large filter sheets manually cut into much smaller pieces, which is a much less precise and much more labor-intensive, expensive, and difficult process. Filter performance was validated by integrating them with thermopile arrays. Demonstration of the FPA will require the integration of two technologies. The first technology is compact, lightweight, robust against cryogenic thermal cycling, and radiation-hard micromachined bandpass filters. They consist of a copper mesh supported on a deep reactive ion-etched silicon frame. This design architecture is advantageous when constructing a lightweight and compact instrument because (1) the frame acts like a jig and facilitates filter integration with the FPA, (2) the frame can be designed so as to maximize the FPA field of view, (3) the frame can be simultaneously used as a baffle for mitigating crosstalk, and (4) micron-scale alignment features can be patterned so as to permit high-precision filter stacking and, consequently, increase the filter bandwidth and sharpen the out-of-band rolloff. The second technology consists of leveraging, from another project, compact and lightweight Bi0.87Sb0.13/Sb arrayed thermopiles

  12. Features of the compact photon storage ring

    NASA Astrophysics Data System (ADS)

    Yamada, Hironari; Tsutsui, Hiroshi; Shimoda, Koichi; Mima, Kunioki

    1993-07-01

    The compact photon storage ring (PhSR) is a hybrid machine that features both linac driven FEL and storage ring driven FEL. The lasing condition is determined by the exactly circular electron storage ring, but a continuous electron injection is possible without disturbing the lasing. An effect of coherent synchrotron radiation takes an important role in the lasing. It is found that the compact PhSR is promising in lasing up to a wavelength of less than 10 μm with 10 A accumulated current.

  13. Momentum compaction and phase slip factor

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2010-10-01

    Section 2.3.11 of the Handbook of Accelerator Physics and Engineering on Landau damping is updated. The slip factor and its higher orders are given in terms of the various orders of the momentum compaction. With the aid of a simplified FODO lattice, formulas are given for the alteration of the lower orders of the momentum compaction by various higher multipole magnets. The transition to isochronicity is next demonstrated. Formulas are given for the extraction of the first three orders of the slip factor from the measurement of the synchrotron tune while changing the rf frequency. Finally bunch-length compression experiments in semi-isochronous rings are reported.

  14. Remote vacuum compaction of compressible hazardous waste

    DOEpatents

    Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

    1998-10-06

    A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

  15. COMPACT ACCELERATOR CONCEPT FOR PROTON THERAPY

    SciTech Connect

    Caporaso, G; Sampayan, S; Chen, Y; Harris, J; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Nunnally, W; Paul, A; Poole, B; Rhodes, M; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J

    2006-08-18

    A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is being developed as a compact flash x-ray radiography source. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be presented.

  16. Compact, Robust Chips Integrate Optical Functions

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Located in Bozeman, Montana, AdvR Inc. has been an active partner in NASA's Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs. Langley Research Center engineers partnered with AdvR through the SBIR program to develop new, compact, lightweight electro-optic components for remote sensing systems. While the primary customer for this technology will be NASA, AdvR foresees additional uses for its NASA-derived circuit chip in the fields of academic and industrial research anywhere that compact, low-cost, stabilized single-frequency lasers are needed.

  17. Subunit structure of a class A aspartate transcarbamoylase from Pseudomonas fluorescens.

    PubMed Central

    Bergh, S T; Evans, D R

    1993-01-01

    The class A aspartate transcarbamoylase (ATCase, EC 2.1.3.2) from Pseudomonas fluorescens was purified to homogeneity with retention of full catalytic and regulatory functions. Careful determinations under conditions that minimized proteolysis showed that the molecule is a 1:1 stoichiometric complex of two polypeptide chains of 34 and 45 kDa. Pyridoxal phosphate is a competitive inhibitor of the enzyme (Ki = 1 microM). Reduction of the pyridoxal phosphate enzyme adduct with sodium boro[3H]hydride showed that the active site is located on the 34-kDa polypeptide. Affinity labeling with 5'-[p-(fluorosulfonyl)benzoyl]adenosine, an ATP analog, suggested that the regulatory site is also located on the 34-kDa species. While the function of the 45-kDa subunit is unknown, neither carbamoyl phosphate synthetase nor dihydroorotase activities are associated with the ATCase. The molecular mass of the enzyme was determined by gel filtration, sedimentation velocity, and electron microscopy to be 464 kDa. Thus the enzyme is composed of six copies of the 34-kDa polypeptide and six copies of the 45-kDa polypeptide. The molecule has a Stokes' ratio of 70.9 A and a frictional ratio of 1.37, suggesting a compact globular shape. We propose that the P. fluorescens ATCase is composed of two trimers of 34-kDa catalytic chains and is likely to be a D3 dodecamer with an arrangement of subunits analogous to that of the class B ATCase molecules. Images Fig. 2 Fig. 3 Fig. 5 PMID:8234318

  18. NOX Activation by Subunit Interaction and Underlying Mechanisms in Disease

    PubMed Central

    Rastogi, Radhika; Geng, Xiaokun; Li, Fengwu; Ding, Yuchuan

    2017-01-01

    Nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase (NOX) is an enzyme complex with the sole function of producing superoxide anion and reactive oxygen species (ROS) at the expense of NADPH. Vital to the immune system as well as cellular signaling, NOX is also involved in the pathologies of a wide variety of disease states. Particularly, it is an integral player in many neurological diseases, including stroke, TBI, and neurodegenerative diseases. Pathologically, NOX produces an excessive amount of ROS that exceed the body’s antioxidant ability to neutralize them, leading to oxidative stress and aberrant signaling. This prevalence makes it an attractive therapeutic target and as such, NOX inhibitors have been studied and developed to counter NOX’s deleterious effects. However, recent studies of NOX have created a better understanding of the NOX complex. Comprised of independent cytosolic subunits, p47-phox, p67-phox, p40-phox and Rac, and membrane subunits, gp91-phox and p22-phox, the NOX complex requires a unique activation process through subunit interaction. Of these subunits, p47-phox plays the most important role in activation, binding and translocating the cytosolic subunits to the membrane and anchoring to p22-phox to organize the complex for NOX activation and function. Moreover, these interactions, particularly that between p47-phox and p22-phox, are dependent on phosphorylation initiated by upstream processes involving protein kinase C (PKC). This review will look at these interactions between subunits and with PKC. It will focus on the interaction involving p47-phox with p22-phox, key in bringing the cytosolic subunits to the membrane. Furthermore, the implication of these interactions as a target for NOX inhibitors such as apocynin will be discussed as a potential avenue for further investigation, in order to develop more specific NOX inhibitors based on the inhibition of NOX assembly and activation. PMID:28119569

  19. Protein Expression of Proteasome Subunits in Elderly Patients with Schizophrenia

    PubMed Central

    Scott, Madeline R; Rubio, Maria D; Haroutunian, Vahram; Meador-Woodruff, James H

    2016-01-01

    The ubiquitin proteasome system (UPS) is a major regulator of protein processing, trafficking, and degradation. While protein ubiquitination is utilized for many cellular processes, one major function of this system is to target proteins to the proteasome for degradation. In schizophrenia, studies have found UPS transcript abnormalities in both blood and brain, and we have previously reported decreased protein expression of ubiquitin-associated proteins in brain. To test whether the proteasome is similarly dysregulated, we measured the protein expression of proteasome catalytic subunits as well as essential subunits from proteasome regulatory complexes in 14 pair-matched schizophrenia and comparison subjects in superior temporal cortex. We found decreased expression of Rpt1, Rpt3, and Rpt6, subunits of the 19S regulatory particle essential for ubiquitin-dependent degradation by the proteasome. Additionally, the α subunit of the 11S αβ regulatory particle, which enhances proteasomal degradation of small peptides and unfolded proteins, was also decreased. Haloperidol-treated rats did not have altered expression of these subunits, suggesting the changes we observed in schizophrenia are likely not due to chronic antipsychotic treatment. Interestingly, expression of the catalytic subunits of both the standard and immunoproteasome were unchanged, suggesting the abnormalities we observed may be specific to the complexed state of the proteasome. Aging has significant effects on the proteasome, and several subunits (20S β2, Rpn10, Rpn13, 11Sβ, and 11Sγ) were significantly correlated with subject age. These data provide further evidence of dysfunction of the ubiquitin-proteasome system in schizophrenia, and suggest that altered proteasome activity may be associated with the pathophysiology of this illness. PMID:26202105

  20. The effect of shearing on the buoyant migration of melt in compacting-dissolution channels

    NASA Astrophysics Data System (ADS)

    Baltzell, C.; Parmentier, E.; Liang, Y.; Tirupathi, S.

    2013-12-01

    Melt migration in the mantle by porous flow through compacting, high porosity dissolution channels may occur in a variety of settings including both the upwelling mantle beneath spreading centers and the flowing mantle wedge at convergent plate boundaries. Such channels may form by a positive feedback between dissolution and melt percolation. Previous studies [1, 2] have considered the compacting-dissolution channels in the presence of a uniform upwelling mantle flow. In this study the analysis of mantle flow beneath the plate boundaries was extended by introducing a horizontal shearing component. A numerical experiment was formulated using the finite element software deal.II [3] applying a high order Discontinuous Galerkin (DG) method to examine melt flow in a deforming, porous matrix. The conditions are similar to those in [2] except the addition of a prescribed horizontal shear component in the solid matrix. Melt migration occurs within a rectangular domain subject to horizontal periodic boundary conditions. Initially a Gaussian perturbation in the porosity at the base extends vertically through the domain defining a melt channel. By varying the shear and upwelling rates, the porosity and matrix dissolution were examined to determine the behavior of the channel and melt flow. Models of buoyant melt transport through dissolution channels in upwelling mantle sheared on horizontal planes show that shearing deformation introduces several effects that could have important consequences for melt migration. Shearing tends to rotate dissolution channels away from the vertical thus reducing the component of buoyancy acting along the channels and decreasing the stability of the channel. The channels remain more vertical than would be expected if they followed the matrix flow, as determined by the dissolution. Channels thus migrate horizontally relative to the mantle matrix and melt flows horizontally through dissolution channels. Evolution of the channels depends on the

  1. Structural predictions of AgfA, the insoluble fimbrial subunit of Salmonella thin aggregative fimbriae.

    PubMed

    Collinson, S K; Parker, J M; Hodges, R S; Kay, W W

    1999-07-16

    The unusually stable and multifunctional, thin aggregative fimbriae common to all Salmonella spp. are principally polymers of the fimbrin subunit, AgfA. AgfA of Salmonella enteritidis consists of two domains: a protease-sensitive, 22 amino acid residue N-terminal region and a protease-resistant, 109 residue C-terminal core. The unusual amino acid sequence of the AgfA core region comprises two-, five- and tenfold internal sequence homology patterns reflected in five conserved, 18-residue tandem repeats. These repeats have the consensus sequence, Sx5QxGx2NxAx3Q and are linked together by four or five residues, (x)xAx2. The predicted secondary structure for this unusual arrangement of tandem repeats in AgfA indicates mainly extended conformation with the beta strands linked by four to six residues. Candidate proteins of known structure with motifs of alternating beta strands and short loops were selected from folds described in SCOP as a source of coordinates for AgfA model construction. Three all-beta class motifs selected from the Serratia marcescens metalloprotease, myelin P2 protein or vitelline membrane outer protein I were used for initial AgfA homology build-up procedures ultimately resulting in three structural models; beta barrel, beta prism and parallel beta helix. The beta barrel model is a compact, albeit irregular structure, with the beta strands arranged in two antiparallel beta sheet faces. The beta prism model does not reflect the 5 or 10-fold symmetry of the AgfA primary sequence. However, the favored, parallel beta helix model is a compact coil of ten helically arranged beta strands forming two parallel beta sheet faces. This arrangement predicts a regular, potentially stable, C-terminal core region consistent with the observed tandem repeat sequences, protease-resistance and strong tendency of this fimbrin to oligomerize and aggregate. Positional conservation of amino acid residues in AgfA and the Escherichia coli AgfA homologue, CsgA, provides

  2. Generalized matrix inversion is not harder than matrix multiplication

    NASA Astrophysics Data System (ADS)

    Petkovic, Marko D.; Stanimirovic, Predrag S.

    2009-08-01

    Starting from the Strassen method for rapid matrix multiplication and inversion as well as from the recursive Cholesky factorization algorithm, we introduced a completely block recursive algorithm for generalized Cholesky factorization of a given symmetric, positive semi-definite matrix . We used the Strassen method for matrix inversion together with the recursive generalized Cholesky factorization method, and established an algorithm for computing generalized {2,3} and {2,4} inverses. Introduced algorithms are not harder than the matrix-matrix multiplication.

  3. Extracellular matrix structure.

    PubMed

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented.

  4. Matrix interdiction problem

    SciTech Connect

    Pan, Feng; Kasiviswanathan, Shiva

    2010-01-01

    In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

  5. Differential compaction behaviour of roller compacted granules of clopidogrel bisulphate polymorphs.

    PubMed

    Khomane, Kailas S; Bansal, Arvind K

    2014-09-10

    In the present work, in-die and out-of-die compaction behaviour of dry-granulated powders of clopidogrel bisulphate (CLP) polymorphs, form I and form II, was investigated using a fully instrumented rotary tablet press. Each polymorph was compacted at three different roller pressures [70.3 (S1), 105.5 (S2) and 140.6 (S3)kgf/cm(2)], and obtained granules were characterized for their physico-mechanical properties. Compaction data were analyzed for out-of-die compressibility, tabletability and compactibility profiles, and in-die Heckel, Kawakita and Walker analysis. The roller compacted granules of both forms showed markedly different tabletting behaviour. Roller pressure exhibited a trend on compaction behaviour of form I granules, whereas, in case of form II, the effect was insignificant. Tabletability of the six granule batches follows the order; I_S1>I_S2>I_S3>II_S1≈II_S2≈II_S3. In case of form I, the reduced tabletability of the granules compacted at higher roller pressure was attributed to the decreased compressibility and plastic deformation. This was confirmed by compressibility plot and various mathematical parameters derived from Heckel (Py), Kawakita (1/b) and Walker (W) equations. The reduced tabletability of form I granules was due to 'granule hardening' during roller compaction. On the other hand, insignificant effect of roller compaction on tabletting behaviour of form II granules was attributed to brittle fragmentation. The extensive fragmentation of granules offered new 'clean' surfaces and higher contact points that negated the effect of granule hardening.

  6. Matrixed business support comparison study.

    SciTech Connect

    Parsons, Josh D.

    2004-11-01

    The Matrixed Business Support Comparison Study reviewed the current matrixed Chief Financial Officer (CFO) division staff models at Sandia National Laboratories. There were two primary drivers of this analysis: (1) the increasing number of financial staff matrixed to mission customers and (2) the desire to further understand the matrix process and the opportunities and challenges it creates.

  7. Rheocasting Al Matrix Composites

    NASA Astrophysics Data System (ADS)

    Girot, F. A.; Albingre, L.; Quenisset, J. M.; Naslain, R.

    1987-11-01

    Aluminum alloy matrix composites reinforced by SiC short fibers (or whiskers) can be prepared by rheocasting, a process which consists of the incorporation and homogeneous distribution of the reinforcement by stirring within a semi-solid alloy. Using this technique, composites containing fiber volume fractions in the range of 8-15%, have been obtained for various fibers lengths (i.e., 1 mm, 3 mm and 6 mm for SiC fibers). This paper attempts to delineate the best compocasting conditions for aluminum matrix composites reinforced by short SiC (e.g Nicalon) or SiC whiskers (e.g., Tokamax) and characterize the resulting microstructures.

  8. Density matrix perturbation theory.

    PubMed

    Niklasson, Anders M N; Challacombe, Matt

    2004-05-14

    An orbital-free quantum perturbation theory is proposed. It gives the response of the density matrix upon variation of the Hamiltonian by quadratically convergent recursions based on perturbed projections. The technique allows treatment of embedded quantum subsystems with a computational cost scaling linearly with the size of the perturbed region, O(N(pert.)), and as O(1) with the total system size. The method allows efficient high order perturbation expansions, as demonstrated with an example involving a 10th order expansion. Density matrix analogs of Wigner's 2n+1 rule are also presented.

  9. The first transmembrane domain (TM1) of β2-subunit binds to the transmembrane domain S1 of α-subunit in BK potassium channels

    PubMed Central

    Morera, Francisco J.; Alioua, Abderrahmane; Kundu, Pallob; Salazar, Marcelo; Gonzalez, Carlos; Martinez, Agustin D.; Stefani, Enrico; Toro, Ligia; Latorre, Ramon

    2012-01-01

    The BK channel is one of the most broadly expressed ion channels in mammals. In many tissues, the BK channel pore-forming α-subunit is associated to an auxiliary β-subunit that modulates the voltage- and Ca2+-dependent activation of the channel. Structural components present in β-subunits that are important for the physical association with the α-subunit are yet unknown. Here, we show through co-immunoprecipitation that the intracellular C-terminus, the second transmembrane domain (TM2) and the extracellular loop of the β2-subunit are dispensable for association with the α-subunit pointing transmembrane domain 1 (TM1) as responsible for the interaction. Indeed, the TOXCAT assay for transmembrane protein–protein interactions demonstrated for the first time that TM1 of the β2-subunit physically binds to the transmembrane S1 domain of the α-subunit. PMID:22710124

  10. Alpha v integrin subunit is predominantly located in nervous tissue and skeletal muscle during mouse development.

    PubMed

    Hirsch, E; Gullberg, D; Balzac, F; Altruda, F; Silengo, L; Tarone, G

    1994-10-01

    Alpha v integrin subunit can dimerize with different beta subunits to form receptors for several matrix proteins. The function of these receptors in vivo is still largely unknown. We examined the localization of alpha v integrin during mouse development and showed that its distribution is dynamically regulated in the glia of the central nervous system and in skeletal muscle. Immunoreactivity in the neural tube was firstly localized at embryonic day 10.5 (E10.5) around cell bodies lining the lumen and along tiny fibres extending towards the outer margin. At E12.5 alpha v distribution follows the highly defined pattern of the radial glia: fascicles of immunoreactive fibres form parallel palisades, in particular along the hindbrain and the spinal cord. At E15.5, although with weaker intensity, alpha v was still detectable in radial glia fibres, and it codistributed with glial fibrillary acidic protein positive fascicles. After birth (P8) alpha v immunoreactivity in the brain and spinal cord decreased dramatically, but remained high in the radial glia of the cerebellum. In adult mice alpha v reactivity in the central nervous system disappeared. During myogenesis alpha v appears at E10.5 in myotomal cells and from E12.5 alpha v was evident in myoblasts and in myotubes. In the developing skeletal muscle of E15.5 embryos, immunoreactivity became more concentrated in the apical portion of the myotubes. In adult striated muscle the amount of alpha v subunit dramatically declined and immunostaining was no longer detectable. During development, alpha v was weakly evident in other sites including heart and endothelia of blood vessels, mesonephric tubula, smooth muscle of the digestive tract, and bronchia. Comparative analysis of the localization of alpha v, alpha 3, and alpha 5 integrin subunits indicated that alpha v has a unique and highly regulated distribution pattern. The distribution in the nervous system is consistent with a role of alpha v in neuron-glia interaction

  11. A distinct holoenzyme organization for two-subunit pyruvate carboxylase

    PubMed Central

    Choi, Philip H.; Jo, Jeanyoung; Lin, Yu-Cheng; Lin, Min-Han; Chou, Chi-Yuan; Dietrich, Lars E. P.; Tong, Liang

    2016-01-01

    Pyruvate carboxylase (PC) has important roles in metabolism and is crucial for virulence for some pathogenic bacteria. PC contains biotin carboxylase (BC), carboxyltransferase (CT) and biotin carboxyl carrier protein (BCCP) components. It is a single-chain enzyme in eukaryotes and most bacteria, and functions as a 500 kD homo-tetramer. In contrast, PC is a two-subunit enzyme in a collection of Gram-negative bacteria, with the α subunit containing the BC and the β subunit the CT and BCCP domains, and it is believed that the holoenzyme has α4β4 stoichiometry. We report here the crystal structures of a two-subunit PC from Methylobacillus flagellatus. Surprisingly, our structures reveal an α2β4 stoichiometry, and the overall architecture of the holoenzyme is strikingly different from that of the homo-tetrameric PCs. Biochemical and mutagenesis studies confirm the stoichiometry and other structural observations. Our functional studies in Pseudomonas aeruginosa show that its two-subunit PC is important for colony morphogenesis. PMID:27708276

  12. Realisation of a compact methane optical clock

    SciTech Connect

    Gubin, M A; Kireev, A N; Konyashchenko, A V; Kryukov, P G; Tausenev, A V; Tyurikov, D A; Shelkovnikov, A S

    2008-07-31

    A compact optical clock based on a double-mode He-Ne/CH{sub 4} optical frequency standard and a femtosecond Er{sup 3+} fibre laser is realised and its stability against a commercial hydrogen frequency standard is measured. (letters)

  13. Compact, Flexible Telemetry-Coding Circuits

    NASA Technical Reports Server (NTRS)

    Katz, Richard B.; Tooley, Matthew; Settles, Beverly

    1993-01-01

    Circuits encoding binary telemetry data designed to synthesize any number of selectable codes. Designed for use aboard spacecraft, with features also making them attractive for terrestrial applications: Simple and compact relative to prior coding circuits, built with commercial integrated circuits, and incorporate protective redundancy. Output distortions minimized, and spurious attenuated and/or abbreviated output pulses eliminated.

  14. Compact range for variable-zone measurements

    DOEpatents

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-01-01

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  15. Compact range for variable-zone measurements

    DOEpatents

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-08-02

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  16. Compact range for variable-zone measurements

    DOEpatents

    Burnside, W.D.; Rudduck, R.C.; Yu, J.S.

    1987-02-27

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector. 2 figs.

  17. Soil compaction across the old rotation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluating soil compaction levels across the Old Rotation, the world’s oldest continuous cotton (Gossypium hirsutum L.) experiment, has not been conducted since the experiment transitioned to conservation tillage and high residue cover crops with and without irrigation. Our objective was to charact...

  18. Compact Electric- And Magnetic-Field Sensor

    NASA Technical Reports Server (NTRS)

    Winterhalter, Daniel; Smith, Edward

    1994-01-01

    Compact sensor measures both electric and magnetic fields. Includes both short electric-field dipole and search-coil magnetometer. Three mounted orthogonally providing triaxial measurements of electromagnetic field at frequencies ranging from near 0 to about 10 kHz.

  19. Compact Hydraulic Excavator and Support Unit

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

    Continuous-coal-mining machine maneuverable. Hydraulic coal excavator combined with chock, or roof-support structure, in self-contained unit that moves itself forward as it removes coal from seam. Unlike previous such units, new machine compact enough to be easily maneuverable; even makes small-radius right-angle turns.

  20. HI absorption in nearby compact radio galaxies

    NASA Astrophysics Data System (ADS)

    Glowacki, M.; Allison, J. R.; Sadler, E. M.; Moss, V. A.; Curran, S. J.; Musaeva, A.; Deng, C.; Parry, R.; Sligo, M. C.

    2017-01-01

    HI absorption studies yield information on both AGN feeding and feedback processes. This AGN activity interacts with the neutral gas in compact radio sources, which are believed to represent the young or recently re-triggered AGN population. We present the results of a survey for HI absorption in a sample of 66 compact radio sources at 0.040 < z < 0.096 with the Australia Telescope Compact Array. In total, we obtained seven detections, five of which are new, with a large range of peak optical depths (3% to 87%). Of the detections, 71% exhibit asymmetric, broad (ΔvFWHM > 100 km s-1) features, indicative of disturbed gas kinematics. Such broad, shallow and offset features are also found within low-excitation radio galaxies which is attributed to disturbed circumnuclear gas, consistent with early-type galaxies typically devoid of a gas-rich disk. Comparing mid-infrared colours of our galaxies with HI detections indicates that narrow and deep absorption features are preferentially found in late-type and high-excitation radio galaxies in our sample. These features are attributed to gas in galactic disks. By combining XMM-Newton archival data with 21-cm data, we find support that absorbed X-ray sources may be good tracers of HI content within the host galaxy. This sample extends previous HI surveys in compact radio galaxies to lower radio luminosities and provides a basis for future work exploring the higher redshift universe.

  1. Compact microwave cavity for hydrogen atomic clock

    NASA Technical Reports Server (NTRS)

    Zhang, Dejun; Zhang, Yan; Fu, Yigen; Zhang, Yanjun

    1992-01-01

    A summary is presented that introduces the compact microwave cavity used in the hydrogen atomic clock. Special emphasis is placed on derivation of theoretical calculating equations of main parameters of the microwave cavity. A brief description is given of several methods for discriminating the oscillating modes. Experimental data and respective calculated values are also presented.

  2. Materials needs for compact fusion reactors

    SciTech Connect

    Krakowski, R.A.

    1983-01-01

    The economic prospects for magnetic fusion energy can be dramatically improved if for the same total power output the fusion neutron first-wall (FW) loading and the system power density can be increased by factors of 3 to 5 and 10 to 30, respectively. A number of compact fusion reactor embodiments have been proposed, all of which would operate with increased FW loadings, would use thin (0.5 to 0.6 m) blankets, and would confine quasi-steady-state plasma with resistive, water-cooled copper or aluminum coils. Increased system power density (5 to 15 MWt/m/sup 3/ versus 0.3 to 0.5 MW/m/sup 3/), considerably reduced physical size of the fusion power core (FPC), and appreciably reduced economic leverage exerted by the FPC and associated physics result. The unique materials requirements anticipated for these compact reactors are outlined against the well documented backdrop provided by similar needs for the mainline approaches. Surprisingly, no single materials need that is unique to the compact systems is identified; crucial uncertainties for the compact approaches must also be addressed by the mainline approaches, particularly for in-vacuum components (FWs, limiters, divertors, etc.).

  3. Compaction and Wear Concerns on Sports Fields.

    ERIC Educational Resources Information Center

    Gillan, John

    1999-01-01

    Describes relatively simple measures athletic-facility managers can use to alleviate the turf destruction and compaction of athletic fields including seed and soil amendments and modifications on team practice. Ways of enhancing surface traction and lessen surface hardness are explored. (GR)

  4. Compact Tactile Sensors for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.; Lussy, David; Gaudiano, Frank; Hulse, Aaron; Diftler, Myron A.; Rodriguez, Dagoberto; Bielski, Paul; Butzer, Melisa

    2004-01-01

    Compact transducer arrays that measure spatial distributions of force or pressure have been demonstrated as prototypes of tactile sensors to be mounted on fingers and palms of dexterous robot hands. The pressure- or force-distribution feedback provided by these sensors is essential for the further development and implementation of robot-control capabilities for humanlike grasping and manipulation.

  5. Compact, Lightweight Servo-Controllable Brakes

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  6. Compact Radar at Empire Challenge 2011

    DTIC Science & Technology

    2011-09-01

    Harrison, Eric D. Adler, David A. Wikner , Russell W. Harris, and Ronald J. Wellman) to the Compact Radar crew (Edward A. Viveiros, Jr., Steven...RDRL SER M A ZAGHLOUL ATTN RDRL SER M B NELSON ATTN RDRL SER M C DIETLEIN ATTN RDRL SER M C PATTERSON ATTN RDRL SER M D WIKNER

  7. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2006-01-01

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars - compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.

  8. Mitotic chromosome compaction via active loop extrusion

    NASA Astrophysics Data System (ADS)

    Goloborodko, Anton; Imakaev, Maxim; Marko, John; Mirny, Leonid; MIT-Northwestern Team

    During cell division, two copies of each chromosome are segregated from each other and compacted more than hundred-fold into the canonical X-shaped structures. According to earlier microscopic observations and the recent Hi-C study, chromosomes are compacted into arrays of consecutive loops of ~100 kilobases. Mechanisms that lead to formation of such loop arrays are largely unknown. Here we propose that, during cell division, chromosomes can be compacted by enzymes that extrude loops on chromatin fibers. First, we use computer simulations and analytical modeling to show that a system of loop-extruding enzymes on a chromatin fiber self-organizes into an array of consecutive dynamic loops. Second, we model the process of loop extrusion in 3D and show that, coupled with the topo II strand-passing activity, it leads to robust compaction and segregation of sister chromatids. This mechanism of chromosomal condensation and segregation does not require additional proteins or specific DNA markup and is robust against variations in the number and properties of such loop extruding enzymes. Work at NU was supported by the NSF through Grants DMR-1206868 and MCB-1022117, and by the NIH through Grants GM105847 and CA193419. Work at MIT was supported by the NIH through Grants GM114190 R01HG003143.

  9. Compact continuum brain model for human electroencephalogram

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Shin, H.-B.; Robinson, P. A.

    2007-12-01

    A low-dimensional, compact brain model has recently been developed based on physiologically based mean-field continuum formulation of electric activity of the brain. The essential feature of the new compact model is a second order time-delayed differential equation that has physiologically plausible terms, such as rapid corticocortical feedback and delayed feedback via extracortical pathways. Due to its compact form, the model facilitates insight into complex brain dynamics via standard linear and nonlinear techniques. The model successfully reproduces many features of previous models and experiments. For example, experimentally observed typical rhythms of electroencephalogram (EEG) signals are reproduced in a physiologically plausible parameter region. In the nonlinear regime, onsets of seizures, which often develop into limit cycles, are illustrated by modulating model parameters. It is also shown that a hysteresis can occur when the system has multiple attractors. As a further illustration of this approach, power spectra of the model are fitted to those of sleep EEGs of two subjects (one with apnea, the other with narcolepsy). The model parameters obtained from the fittings show good matches with previous literature. Our results suggest that the compact model can provide a theoretical basis for analyzing complex EEG signals.

  10. Compact Apparatus For Growth Of Protein Crystals

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; Miller, Teresa Y.

    1991-01-01

    Compact apparatus proposed specifically for growth of protein crystals in microgravity also used in terrestrial laboratories to initiate and terminate growth at prescribed times automatically. Has few moving parts. Also contains no syringes difficult to clean, load, and unload and introduces contaminant silicon grease into crystallization solution. After growth of crystals terminated, specimens retrieved and transported simply.

  11. Analysis of Technology for Compact Coherent Lidar

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin

    1997-01-01

    In view of the recent advances in the area of solid state and semiconductor lasers has created new possibilities for the development of compact and reliable coherent lidars for a wide range of applications. These applications include: Automated Rendezvous and Capture, wind shear and clear air turbulence detection, aircraft wake vortex detection, and automobile collision avoidance. The work performed by the UAH personnel under this Delivery Order, concentrated on design and analyses of a compact coherent lidar system capable of measuring range and velocity of hard targets, and providing air mass velocity data. The following is the scope of this work. a. Investigate various laser sources and optical signal detection configurations in support of a compact and lightweight coherent laser radar to be developed for precision range and velocity measurements of hard and fuzzy targets. Through interaction with MSFC engineers, the most suitable laser source and signal detection technique that can provide a reliable compact and lightweight laser radar design will be selected. b. Analyze and specify the coherent laser radar system configuration and assist with its optical and electronic design efforts. Develop a system design including its optical layout design. Specify all optical components and provide the general requirements of the electronic subsystems including laser beam modulator and demodulator drivers, detector electronic interface, and the signal processor. c. Perform a thorough performance analysis to predict the system measurement range and accuracy. This analysis will utilize various coherent laser radar sensitivity formulations and different target models.

  12. Investigation of HMA compactability using GPR technique

    NASA Astrophysics Data System (ADS)

    Plati, Christina; Georgiou, Panos; Loizos, Andreas

    2014-05-01

    In-situ field density is often regarded as one of the most important controls used to ensure that an asphalt pavement being placed is of high quality. The achieved density results from the effectiveness of the applied compaction mode on the Hot Mix Asphalt (HMA) layer. It is worthwhile mentioning that the proper compaction of HMA increases pavement fatigue life, decreases the amount of permanent deformation or rutting, reduces the amount of oxidation or aging, decreases moisture damage or stripping, increases strength and internal stability, and may decrease slightly the amount of low-temperature cracking that may occur in the mix. Conventionally, the HMA density in the field is assessed by direct destructive methods, including through the cutting of samples or drilling cores. These methods are characterized by a high accuracy, although they are intrusive and time consuming. In addition, they provide local information, i.e. information only for the exact test location. To overcome these limitations, the use of non-intrusive techniques is often recommended. The Ground Penetrating Radar (GPR) technique is an example of a non-intrusive technique that has been increasingly used for pavement investigations over the years. GPR technology is practical and application-oriented with the overall design concept, as well as the hardware, usually dependent on the target type and the material composing the target and its surroundings. As the sophistication of operating practices increases, the technology matures and GPR becomes an intelligent sensor system. The intelligent sensing deals with the expanded range of GPR applications in pavements such as determining layer thickness, detecting subsurface distresses, estimating moisture content, detecting voids and others. In addition, the practice of using GPR to predict in-situ field density of compacted asphalt mixture material is still under development and research; however the related research findings seem to be promising

  13. Matrix Embedded Organic Synthesis

    NASA Astrophysics Data System (ADS)

    Kamakolanu, U. G.; Freund, F. T.

    2016-05-01

    In the matrix of minerals such as olivine, a redox reaction of the low-z elements occurs. Oxygen is oxidized to the peroxy state while the low-Z-elements become chemically reduced. We assign them a formula [CxHyOzNiSj]n- and call them proto-organics.

  14. Constructing the matrix

    NASA Astrophysics Data System (ADS)

    Elliott, John

    2012-09-01

    As part of our 'toolkit' for analysing an extraterrestrial signal, the facility for calculating structural affinity to known phenomena must be part of our core capabilities. Without such a resource, we risk compromising our potential for detection and decipherment or at least causing significant delay in the process. To create such a repository for assessing structural affinity, all known systems (language parameters) need to be structurally analysed to 'place' their 'system' within a relational communication matrix. This will need to include all known variants of language structure, whether 'living' (in current use) or ancient; this must also include endeavours to incorporate yet undeciphered scripts and non-human communication, to provide as complete a picture as possible. In creating such a relational matrix, post-detection decipherment will be assisted by a structural 'map' that will have the potential for 'placing' an alien communication with its nearest known 'neighbour', to assist subsequent categorisation of basic parameters as a precursor to decipherment. 'Universal' attributes and behavioural characteristics of known communication structure will form a range of templates (Elliott, 2001 [1] and Elliott et al., 2002 [2]), to support and optimise our attempt at categorising and deciphering the content of an extraterrestrial signal. Detection of the hierarchical layers, which comprise intelligent, complex communication, will then form a matrix of calculations that will ultimately score affinity through a relational matrix of structural comparison. In this paper we develop the rationales and demonstrate functionality with initial test results.

  15. Matrix product state renormalization

    NASA Astrophysics Data System (ADS)

    Bal, M.; Rams, M. M.; Zauner, V.; Haegeman, J.; Verstraete, F.

    2016-11-01

    The truncation or compression of the spectrum of Schmidt values is inherent to the matrix product state (MPS) approximation of one-dimensional quantum ground states. We provide a renormalization group picture by interpreting this compression as an application of Wilson's numerical renormalization group along the imaginary time direction appearing in the path integral representation of the state. The location of the physical index is considered as an impurity in the transfer matrix and static MPS correlation functions are reinterpreted as dynamical impurity correlations. Coarse-graining the transfer matrix is performed using a hybrid variational ansatz based on matrix product operators, combining ideas of MPS and the multiscale entanglement renormalization ansatz. Through numerical comparison with conventional MPS algorithms, we explicitly verify the impurity interpretation of MPS compression, as put forward by V. Zauner et al. [New J. Phys. 17, 053002 (2015), 10.1088/1367-2630/17/5/053002] for the transverse-field Ising model. Additionally, we motivate the conceptual usefulness of endowing MPS with an internal layered structure by studying restricted variational subspaces to describe elementary excitations on top of the ground state, which serves to elucidate a transparent renormalization group structure ingrained in MPS descriptions of ground states.

  16. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    PubMed

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit.

  17. Dengue vaccine: an update on recombinant subunit strategies.

    PubMed

    Martin, J; Hermida, L

    2016-03-01

    Dengue is an increasing public health problem worldwide, with the four serotypes of the virus infecting over 390 million people annually. There is no specific treatment or antiviral drug for dengue, and prevention is largely limited to controlling the mosquito vectors or disrupting the human-vector contact. Despite the considerable progress made in recent years, an effective vaccine against the virus is not yet available. The development of a dengue vaccine has been hampered by many unique challenges, including the need to ensure the absence of vaccine-induced enhanced severity of disease. Recombinant protein subunit vaccines offer a safer alternative to other vaccine approaches. Several subunit vaccine candidates are presently under development, based on different structural and non-structural proteins of the virus. Novel adjuvants or immunopotentiating strategies are also being tested to improve their immunogenicity. This review summarizes the current status and development trends of subunit dengue vaccines.

  18. Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

    PubMed Central

    Baldauf, Keegan J.; Royal, Joshua M.; Hamorsky, Krystal Teasley; Matoba, Nobuyuki

    2015-01-01

    Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB). CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction. PMID:25802972

  19. Cholera toxin B: one subunit with many pharmaceutical applications.

    PubMed

    Baldauf, Keegan J; Royal, Joshua M; Hamorsky, Krystal Teasley; Matoba, Nobuyuki

    2015-03-20

    Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB). CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  20. Antigenic breadth: a missing ingredient in HSV-2 subunit vaccines?

    PubMed

    Halford, William P

    2014-06-01

    The successful human papillomavirus and hepatitis B virus subunit vaccines contain single viral proteins that represent 22 and 12%, respectively, of the antigens encoded by these tiny viruses. The herpes simplex virus 2 (HSV-2) genome is >20 times larger. Thus, a single protein subunit represents 1% of HSV-2's total antigenic breadth. Antigenic breadth may explain why HSV-2 glycoprotein subunit vaccines have failed in clinical trials, and why live HSV-2 vaccines that express 99% of HSV-2's proteome may be more effective. I review the mounting evidence that live HSV-2 vaccines offer a greater opportunity to stop the spread of genital herpes, and I consider the unfounded 'safety concerns' that have kept live HSV-2 vaccines out of U.S. clinical trials for 25 years.

  1. G alpha 12 and G alpha 13 subunits define a fourth class of G protein alpha subunits.

    PubMed Central

    Strathmann, M P; Simon, M I

    1991-01-01

    Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) are central to the signaling processes of multicellular organisms. We have explored the diversity of the G protein subunits in mammals and found evidence for a large family of genes that encode the alpha subunits. Amino acid sequence comparisons show that the different alpha subunits fall into at least three classes. These classes have been conserved in animals separated by considerable evolutionary distances; they are present in mammals, Drosophila, and nematodes. We have now obtained cDNA clones encoding two murine alpha subunits, G alpha 12 and G alpha 13, that define a fourth class. The translation products are predicted to have molecular masses of 44 kDa and to be insensitive to ADP-ribosylation by pertussis toxin. They share 67% amino acid sequence identity with each other and less than 45% identity with other alpha subunits. Their transcripts can be detected in every tissue examined, although the relative levels of the G alpha 13 message appear somewhat variable. Images PMID:1905812

  2. Subunits of the Schizosaccharomyces pombe RNA polymerase II: enzyme purification and structure of the subunit 3 gene.

    PubMed Central

    Azuma, Y; Yamagishi, M; Ishihama, A

    1993-01-01

    To improve our understanding of the structure and function of eukaryotic RNA polymerase II, we purified the enzyme from the fission yeast Schizosaccharomyces pombe. The highly purified RNA polymerase II contained more than eleven polypeptides. The sizes of the largest the second-, and the third-largest polypeptides as measured by SDS-polyacrylamide gel electrophoresis were about 210, 150, and 40 kilodaltons (kDa), respectively, and are similar to those of RPB1, 2, and 3 subunits of Saccharomyces cerevisiae RNA polymerase II. Using the degenerated primers designed after amino acid micro-sequencing of the 40 kDa third-largest polypeptide (subunit 3), we cloned the subunit 3 gene (rpb3) and determined its DNA sequence. Taken together with the sequence of parts of PCR-amplified cDNA, the predicted coding sequence of rpb3, interrupted by two introns, was found to encode a polypeptide of 297 amino acid residues in length with a molecular weight of 34 kDa. The S. pombe subunit 3 contains four structural domains conserved for the alpha-subunit family of RNA polymerase from both eukaryotes and prokaryotes. A putative leucine zipper motif was found to exist in the C-terminal proximal conserved region (domain D). Possible functions of the conserved domains are discussed. Images PMID:8367291

  3. Pressure–temperature evolution of primordial solar system solids during impact-induced compaction

    PubMed Central

    Bland, P. A.; Collins, G. S.; Davison, T. M.; Abreu, N. M.; Ciesla, F. J.; Muxworthy, A. R.; Moore, J.

    2014-01-01

    Prior to becoming chondritic meteorites, primordial solids were a poorly consolidated mix of mm-scale igneous inclusions (chondrules) and high-porosity sub-μm dust (matrix). We used high-resolution numerical simulations to track the effect of impact-induced compaction on these materials. Here we show that impact velocities as low as 1.5 km s−1 were capable of heating the matrix to >1,000 K, with pressure–temperature varying by >10 GPa and >1,000 K over ~100 μm. Chondrules were unaffected, acting as heat-sinks: matrix temperature excursions were brief. As impact-induced compaction was a primary and ubiquitous process, our new understanding of its effects requires that key aspects of the chondrite record be re-evaluated: palaeomagnetism, petrography and variability in shock level across meteorite groups. Our data suggest a lithification mechanism for meteorites, and provide a ‘speed limit’ constraint on major compressive impacts that is inconsistent with recent models of solar system orbital architecture that require an early, rapid phase of main-belt collisional evolution. PMID:25465283

  4. Stiffness of γ subunit of F(1)-ATPase.

    PubMed

    Okuno, Daichi; Iino, Ryota; Noji, Hiroyuki

    2010-11-01

    F(1)-ATPase is a molecular motor in which the γ subunit rotates inside the α(3)β(3) ring upon adenosine triphosphate (ATP) hydrolysis. Recent works on single-molecule manipulation of F(1)-ATPase have shown that kinetic parameters such as the on-rate of ATP and the off-rate of adenosine diphosphate (ADP) strongly depend on the rotary angle of the γ subunit (Hirono-Hara et al. 2005; Iko et al. 2009). These findings provide important insight into how individual reaction steps release energy to power F(1) and also have implications regarding ATP synthesis and how reaction steps are reversed upon reverse rotation. An important issue regarding the angular dependence of kinetic parameters is that the angular position of a magnetic bead rotation probe could be larger than the actual position of the γ subunit due to the torsional elasticity of the system. In the present study, we assessed the stiffness of two different portions of F(1) from thermophilic Bacillus PS3: the internal part of the γ subunit embedded in the α(3)β(3) ring, and the complex of the external part of the γ subunit and the α(3)β(3) ring (and streptavidin and magnetic bead), by comparing rotational fluctuations before and after crosslinkage between the rotor and stator. The torsional stiffnesses of the internal and remaining parts were determined to be around 223 and 73 pNnm/radian, respectively. Based on these values, it was estimated that the actual angular position of the internal part of the γ subunit is one-fourth of the magnetic bead position upon stalling using an external magnetic field. The estimated elasticity also partially explains the accommodation of the intrinsic step size mismatch between F(o) and F(1)-ATPase.

  5. Localisation of AMPK γ subunits in cardiac and skeletal muscles.

    PubMed

    Pinter, Katalin; Grignani, Robert T; Watkins, Hugh; Redwood, Charles

    2013-12-01

    The trimeric protein AMP-activated protein kinase (AMPK) is an important sensor of energetic status and cellular stress, and mutations in genes encoding two of the regulatory γ subunits cause inherited disorders of either cardiac or skeletal muscle. AMPKγ2 mutations cause hypertrophic cardiomyopathy with glycogen deposition and conduction abnormalities; mutations in AMPKγ3 result in increased skeletal muscle glycogen. In order to gain further insight into the roles of the different γ subunits in muscle and into possible disease mechanisms, we localised the γ2 and γ3 subunits, along with the more abundant γ1 subunit, by immunofluorescence in cardiomyocytes and skeletal muscle fibres. The predominant cardiac γ2 variant, γ2-3B, gave a striated pattern in cardiomyocytes, aligning with the Z-disk but with punctate staining similar to T-tubule (L-type Ca(2+) channel) and sarcoplasmic reticulum (SERCA2) markers. In skeletal muscle fibres AMPKγ3 localises to the I band, presenting a uniform staining that flanks the Z-disk, also coinciding with the position of Ca(2+) influx in these muscles. The localisation of γ2-3B- and γ3-containing AMPK suggests that these trimers may have similar functions in the different muscles. AMPK containing γ2-3B was detected in oxidative skeletal muscles which had low expression of γ3, confirming that these two regulatory subunits may be co-ordinately regulated in response to metabolic requirements. Compartmentalisation of AMPK complexes is most likely dependent on the regulatory γ subunit and this differential localisation may direct substrate selection and specify particular functional roles.

  6. Subwavelength metrological chracterization by Mueller matrix polarimeter and finite difference time domain method

    NASA Astrophysics Data System (ADS)

    Adhikari, Achyut; Dev, Kapil; Asundi, Anand

    2016-11-01

    Wire grid polarizers (WGP), are sub-wavelength gratings with applications in display projection system due to their compact size, wide field of view and long-term stability. Measurement and testing of these structures are important to optimize their use. This is done by first measuring the Mueller matrix of the WGP using a Mueller matrix polarimeter. Next the finite difference time domain (FDTD) method is used to simulate a similar Mueller matrix thus providing the period and step height of the WGP. This approach may lead to more generic determination of sub-wavelength structures including diffractive optical structures.

  7. Micelle-Based Adjuvants for Subunit Vaccine Delivery

    PubMed Central

    Trimaille, Thomas; Verrier, Bernard

    2015-01-01

    In the development of subunit vaccines with purified or recombinant antigens for cancer and infectious diseases, the design of improved and safe adjuvants able to efficiently target the antigen presenting cells, such as dendritic cells, represents a crucial challenge. Nanoparticle-based antigen delivery systems have been identified as an innovative strategy to improve the efficacy of subunit vaccines. Among them, self-assembled micellar nanoparticles from amphiphilic (macro)molecules have recently emerged as promising candidates. In this short review, we report on the recent research findings highlighting the versatility and potential of such systems in vaccine delivery. PMID:26426060

  8. Carrier subunit of plasma membrane transporter is required for oxidative folding of its helper subunit.

    PubMed

    Rius, Mònica; Chillarón, Josep

    2012-05-25

    We study the amino acid transport system b(0,+) as a model for folding, assembly, and early traffic of membrane protein complexes. System b(0,+) is made of two disulfide-linked membrane subunits: the carrier, b(0,+) amino acid transporter (b(0,+)AT), a polytopic protein, and the helper, related to b(0,+) amino acid transporter (rBAT), a type II glycoprotein. rBAT ectodomain mutants display folding/trafficking defects that lead to type I cystinuria. Here we show that, in the presence of b(0,+)AT, three disulfides were formed in the rBAT ectodomain. Disulfides Cys-242-Cys-273 and Cys-571-Cys-666 were essential for biogenesis. Cys-673-Cys-685 was dispensable, but the single mutants C673S, and C685S showed compromised stability and trafficking. Cys-242-Cys-273 likely was the first disulfide to form, and unpaired Cys-242 or Cys-273 disrupted oxidative folding. Strikingly, unassembled rBAT was found as an ensemble of different redox species, mainly monomeric. The ensemble did not change upon inhibition of rBAT degradation. Overall, these results indicated a b(0,+)AT-dependent oxidative folding of the rBAT ectodomain, with the initial and probably cotranslational formation of Cys-242-Cys-273, followed by the oxidation of Cys-571-Cys-666 and Cys-673-Cys-685, that was completed posttranslationally.

  9. Spatial Pyramid Covariance based Compact Video Code for Robust Face Retrieval in TV-series.

    PubMed

    Li, Yan; Wang, Ruiping; Cui, Zhen; Shan, Shiguang; Chen, Xilin

    2016-10-10

    We address the problem of face video retrieval in TV-series which searches video clips based on the presence of specific character, given one face track of his/her. This is tremendously challenging because on one hand, faces in TV-series are captured in largely uncontrolled conditions with complex appearance variations, and on the other hand retrieval task typically needs efficient representation with low time and space complexity. To handle this problem, we propose a compact and discriminative representation for the huge body of video data, named Compact Video Code (CVC). Our method first models the face track by its sample (i.e., frame) covariance matrix to capture the video data variations in a statistical manner. To incorporate discriminative information and obtain more compact video signature suitable for retrieval, the high-dimensional covariance representation is further encoded as a much lower-dimensional binary vector, which finally yields the proposed CVC. Specifically, each bit of the code, i.e., each dimension of the binary vector, is produced via supervised learning in a max margin framework, which aims to make a balance between the discriminability and stability of the code. Besides, we further extend the descriptive granularity of covariance matrix from traditional pixel-level to more general patchlevel, and proceed to propose a novel hierarchical video representation named Spatial Pyramid Covariance (SPC) along with a fast calculation method. Face retrieval experiments on two challenging TV-series video databases, i.e., the Big Bang Theory and Prison Break, demonstrate the competitiveness of the proposed CVC over state-of-the-art retrieval methods. In addition, as a general video matching algorithm, CVC is also evaluated in traditional video face recognition task on a standard Internet database, i.e., YouTube Celebrities, showing its quite promising performance by using an extremely compact code with only 128 bits.

  10. Study of Underwater Shock Compaction Device for Compaction of Titanium Diboride Powder

    NASA Astrophysics Data System (ADS)

    Kennedy, G. B.; Kim, Y. K.; Hokamoto, K.; Itoh, S.

    2007-06-01

    Shock compaction for powders has been used to study bulk consolidation of powder materials. Shock compaction has the advantage of processing at low temperatures and short duration to limit effects of high temperatures for long times, such as increased grain size and high energy cost. Many methods of shock loading of powders have been employed: direct contact with explosive, explosively driven flyer plates, and flyer plates launched with light gas or propellant gun. Another method, using explosives to create a shockwave in water that is in contact with a powder container, has been used extensively at Kumamoto University. This work presents a study of the development of the underwater shockwave device and investigates the water container geometry for control of parameters for shockwave peak pressure, duration, and distribution through the powder compaction process. Results of simulations for optimization of shock compaction properties are presented along with measurements from input and propagated manganin gauge pressure measurements obtained from underwater shock compaction of titanium diboride. The hardness measurements throughout the bulk of the shock compacted titanium diboride are discussed.

  11. Study of Underwater Shock Compaction Device for Compaction of Titanium Diboride

    NASA Astrophysics Data System (ADS)

    Kennedy, G. B.; Kim, Y. K.; Hokamoto, K.; Itoh, S.

    2007-12-01

    Shock compaction for powders has been used to study bulk consolidation of powder materials. Shock compaction has the advantage of processing at low temperatures and short duration to limit effects of high temperatures for long times, such as increased grain size and high energy cost. Many methods of shock loading of powders have been employed: direct contact with explosive, explosively driven flyer plates, and flyer plates launched with light gas or propellant gun. Another method, using explosives to create a shockwave in water that is then contact with a powder container, has been used extensively at Kumamoto University. This work presents a study of the development of the underwater shockwave device and investigates the water container geometry for control of parameters for shockwave peak pressure, duration, and distribution through the powder compaction process. Results of simulations for optimization of shock compaction properties are presented along with measurements from manganin gauge pressure measurements obtained from underwater shock compaction of titanium diboride. The goal of this work is to develop a better understanding of the entire compaction process to utilize the in-situ data to modify numerical simulations to predict performance.

  12. The tumor microenvironment: possible role of integrins and the extracellular matrix in tumor biological behavior of intratubular germ cell neoplasia and testicular seminomas.

    PubMed Central

    Timmer, A.; Oosterhuis, J. W.; Schraffordt Koops, H.; Sleijfer, D. T.; Szabo, B. G.; Timens, W.

    1994-01-01

    In the present study, we examined the distribution of integrin subunits and extracellular matrix proteins in normal testis, intratubular germ cell neoplasia (ITGCN), and primary and metastatic seminomas. Compared to normal testis in ITGCN, Sertoli cells showed increased expression of alpha 3, alpha 6, and beta 1 integrin subunits. Malignant intratubular germ cells stained for alpha 3, alpha 6, and beta 1 integrin subunits. Progression of ITGCN to invasive seminoma was associated with loss of alpha 3 integrin subunit expression by tumor cells. Consequent to this loss, it can be speculated that the strong expression on ITGCN may be related to the noninvasive character of the lesion as is also known from other noninvasive tumors. All tumors showed a strong expression of alpha 6 and beta 1 integrin subunits. The alpha 5 integrin subunit was weakly expressed in primary seminomas in all stages. No differences were observed in integrin expression between primary and metastatic tumors. The distribution of extracellular matrix proteins was heterogeneous and revealed clear architectural differences between seminomas that may reflect different stages of tumor stroma formation. To our knowledge, the results presented in this study provide the first information on the possible role of tumor-extracellular matrix interactions in the biological behavior of ITGCN and testicular seminomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8178927

  13. Soil microbial activity as influenced by compaction and straw mulching

    NASA Astrophysics Data System (ADS)

    Siczek, A.; Frąc, M.

    2012-02-01

    Field study was performed on Haplic Luvisol soil to determine the effects of soil compaction and straw mulching on microbial parameters of soil under soybean. Treatments with different compaction were established on unmulched and mulched with straw soil. The effect of soil compaction and straw mulching on the total bacteria number and activities of dehydrogenases, protease, alkaline and acid phosphatases was studied. The results of study indicated the decrease of enzymes activities in strongly compacted soil and their increase in medium compacted soil as compared to no-compacted treatment. Mulch application caused stimulation of the bacteria total number and enzymatic activity in the soil under all compaction levels. Compaction and mulch effects were significant for all analyzed microbial parameters (P<0.001).

  14. Sustaining the compact shape during the quick spontaneous infiltration process with Al-Ti-B4C-CuO powder mixtures

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Lee, Jung-Moo; Cho, Young-Hee; Kim, Su-Hyeon; Yu, Huashun

    2014-09-01

    Aluminum matrix composites with a high volume fraction of reinforcements are fabricated using a quick spontaneous infiltration process through a combustion reaction of an Al-Ti-B4C-CuO powder mixture in molten aluminum. A cold-compacted powder mixture in a cylindrical shape was used as a preform. The effects of the composition of the initial powder mixture on the sustaining of the compact shape were systematically examined and thereby an optimal composition for fabricating sound aluminum matrix composites was suggested. The compact shape was greatly affected by the initial composition of the powder mixture. A sufficiently high relative volume fraction of the solid particles in the compact is critical for sustaining the compact shape during the combustion reaction. The volume fraction of Al and Ti powders in the initial mixture affects whether crumbling of the compact occurs during the ignition delay time. This study can be beneficial to utilizing the Al-Ti-B4C system as to fabricate components with any desired shape.

  15. High molecular weight glutenin subunits in some durum wheat cultivars investigated by means of mass spectrometric techniques.

    PubMed

    Muccilli, Vera; Lo Bianco, Marisol; Cunsolo, Vincenzo; Saletti, Rosaria; Gallo, Giulia; Foti, Salvatore

    2011-11-23

    The primary structures of high molecular weight glutenin subunits (HMW-GS) of 5 Triticum durum Desf. cultivars (Simeto, Svevo, Duilio, Bronte, and Sant'Agata), largely cultivated in the south of Italy, and of 13 populations of the old spring Sicilian durum wheat landrace Timilia (Triticum durum Desf.) (accession nos. 1, 2, 3, 4, 7, 8, 9, 13, 14, 15, SG1, SG2, and SG3) were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and reversed-phase high performance liquid chromatography/nanoelectrospray ionization mass spectrometry (RP-HPLC/nESI-MS/MS). M(r) of the intact proteins determined by MALDI mass spectrometry showed that all the 13 populations of Timilia contained the same two HMW-GS with 75.2 kDa and 86.4 kDa, whereas the other durum wheat cultivars showed the presence of the expected HMW-GS 1By8 and 1Bx7 at 75.1 kDa and 83.1 kDa, respectively. By MALDI mass spectrometry of the tryptic digestion peptides of the isolated HMW-GS of Timilia, the 1Bx and 1By subunits were identified as the NCBInr Acc. No AAQ93629, and AAQ93633, respectively. Sequence verification for HMW-GS 1Bx and 1By both in Simeto and Timilia was obtained by MALDI mass mapping and HPLC/nESI-MSMS of the tryptic peptides. The Bx subunit of Timila presents a sequence similarity of 96% with respect to Simeto, with differences in the insertion of 3 peptides of 5, 9, and 15 amino acids, for a total insertion of 29 amino acids and 25 amino acid substitutions. These differences in the amino acidic sequence account for the determined Δm of 3294 Da between the M(r) of the 1Bx subunits in Timilia and Simeto. Sequence alignment between the two By subunits shows 10 amino acid substitutions and is consistent with the Δm of 148 Da found in the MALDI mass spectra of the intact subunits.

  16. Compact Polarimetry in a Low Frequency Spaceborne Context

    NASA Technical Reports Server (NTRS)

    Truong-Loi, M-L.; Freeman, A.; Dubois-Fernandez, P.; Pottier, E.

    2011-01-01

    Compact polarimetry has been shown to be an interesting alternative mode to full polarimetry when global coverage and revisit time are key issues. It consists on transmitting a single polarization, while receiving on two. Several critical points have been identified, one being the Faraday rotation (FR) correction and the other the calibration. When a low frequency electromagnetic wave travels through the ionosphere, it undergoes a rotation of the polarization plane about the radar line of sight for a linearly polarized wave, and a simple phase shift for a circularly polarized wave. In a low frequency radar, the only possible choice of the transmit polarization is the circular one, in order to guaranty that the scattering element on the ground is illuminated with a constant polarization independently of the ionosphere state. This will allow meaningful time series analysis, interferometry as long as the Faraday rotation effect is corrected for the return path. In full-polarimetric (FP) mode, two techniques allow to estimate the FR: Freeman method using linearly polarized data, and Bickel and Bates theory based on the transformation of the measured scattering matrix to a circular basis. In CP mode, an alternate procedure is presented which relies on the bare surface scattering properties. These bare surfaces are selected by the conformity coefficient, invariant with FR. This coefficient is compared to other published classifications to show its potential in distinguishing three different scattering types: surface, doublebounce and volume. The performances of the bare surfaces selection and FR estimation are evaluated on PALSAR and airborne data. Once the bare surfaces are selected and Faraday angle estimated over them, the correction can be applied over the whole scene. The algorithm is compared with both FP techniques. In the last part of the paper, the calibration of a CP system from the point of view of classical matrix transformation methods in polarimetry is

  17. First elevated-temperature performance testing of coated particle fuel compacts from the AGR-1 irradiation experiment

    SciTech Connect

    Charles A. Baldwin; John D. Hunn; Robert N. Morris; Fred C. Montgomery; Chinthaka M. Silva; Paul A. Demkowicz

    2014-05-01

    In the AGR-1 irradiation experiment, 72 coated-particle fuel compacts were taken to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures. This paper discusses the first post-irradiation test of these mixed uranium oxide/uranium carbide fuel compacts at elevated temperature to examine the fuel performance under a simulated depressurized conduction cooldown event. A compact was heated for 400 h at 1600 degrees C. Release of 85Kr was monitored throughout the furnace test as an indicator of coating failure, while other fission product releases from the compact were periodically measured by capturing them on exchangeable, water-cooled deposition cups. No coating failure was detected during the furnace test, and this result was verified by subsequent electrolytic deconsolidation and acid leaching of the compact, which showed that all SiC layers were still intact. However, the deposition cups recovered significant quantities of silver, europium, and strontium. Based on comparison of calculated compact inventories at the end of irradiation versus analysis of these fission products released to the deposition cups and furnace internals, the minimum estimated fractional losses from the compact during the furnace test were 1.9 x 10-2 for silver, 1.4 x 10-3 for europium, and 1.1 x 10-5 for strontium. Other post-irradiation examination of AGR-1 compacts indicates that similar fractions of europium and silver may have already been released by the intact coated particles during irradiation, and it is therefore likely that the detected fission products released from the compact in this 1600 degrees C furnace test were from residual fission products in the matrix. Gamma analysis of coated particles deconsolidated from the compact after the heating test revealed that silver content within each particle varied considerably; a result that is probably not related to the furnace test, because it has also been observed in other as-irradiated AGR-1 compacts. X

  18. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry

    SciTech Connect

    Rey-Raap, Natalia

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer New treatments for CFL are required considering the aim of Directive 202/96/CE. Black-Right-Pointing-Pointer It is shown that most of the mercury introduced into a CFL is in the phosphor powder. Black-Right-Pointing-Pointer Experimental conditions for microwave-assisted sample digestion followed by AAS measurements are described. Black-Right-Pointing-Pointer By washing the glass it is possible to reduce the concentration below legal limits. - Abstract: In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 {+-} 0.4 ppb of mercury in the vapor phase, 204.16 {+-} 8.9 ppb of mercury in the phosphor powder, and 18.74 {+-} 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  19. Conservation of complete trimethylation of lysine-43 in the rotor ring of c-subunits of metazoan adenosine triphosphate (ATP) synthases.

    PubMed

    Walpole, Thomas B; Palmer, David N; Jiang, Huibing; Ding, Shujing; Fearnley, Ian M; Walker, John E

    2015-04-01

    The rotors of ATP synthases turn about 100 times every second. One essential component of the rotor is a ring of hydrophobic c-subunits in the membrane domain of the enzyme. The rotation of these c-rings is driven by a transmembrane proton-motive force, and they turn against a surface provided by another membrane protein, known as subunit a. Together, the rotating c-ring and the static subunit a provide a pathway for protons through the membrane in which the c-ring and subunit a are embedded. Vertebrate and invertebrate c-subunits are well conserved. In the structure of the bovine F1-ATPase-c-ring subcomplex, the 75 amino acid c-subunit is folded into two transmembrane α-helices linked by a short loop. Each bovine rotor-ring consists of eight c-subunits with the N- and C-terminal α-helices forming concentric inner and outer rings, with the loop regions exposed to the phospholipid head-group region on the matrix side of the inner membrane. Lysine-43 is in the loop region and its ε-amino group is completely trimethylated. The role of this modification is unknown. If the trimethylated lysine-43 plays some important role in the functioning, assembly or degradation of the c-ring, it would be expected to persist throughout vertebrates and possibly invertebrates also. Therefore, we have carried out a proteomic analysis of c-subunits across representative species from different classes of vertebrates and from invertebrate phyla. In the twenty-nine metazoan species that have been examined, the complete methylation of lysine-43 is conserved, and it is likely to be conserved throughout the more than two million extant metazoan species. In unicellular eukaryotes and prokaryotes, when the lysine is conserved it is unmethylated, and the stoichiometries of c-subunits vary from 9-15. One possible role for the trimethylated residue is to provide a site for the specific binding of cardiolipin, an essential component of ATP synthases in mitochondria.

  20. Conservation of Complete Trimethylation of Lysine-43 in the Rotor Ring of c-Subunits of Metazoan Adenosine Triphosphate (ATP) Synthases*

    PubMed Central

    Walpole, Thomas B.; Palmer, David N.; Jiang, Huibing; Ding, Shujing; Fearnley, Ian M.; Walker, John E.

    2015-01-01

    The rotors of ATP synthases turn about 100 times every second. One essential component of the rotor is a ring of hydrophobic c-subunits in the membrane domain of the enzyme. The rotation of these c-rings is driven by a transmembrane proton-motive force, and they turn against a surface provided by another membrane protein, known as subunit a. Together, the rotating c-ring and the static subunit a provide a pathway for protons through the membrane in which the c-ring and subunit a are embedded. Vertebrate and invertebrate c-subunits are well conserved. In the structure of the bovine F1-ATPase-c-ring subcomplex, the 75 amino acid c-subunit is folded into two transmembrane α-helices linked by a short loop. Each bovine rotor-ring consists of eight c-subunits with the N- and C-terminal α-helices forming concentric inner and outer rings, with the loop regions exposed to the phospholipid head-group region on the matrix side of the inner membrane. Lysine-43 is in the loop region and its ε-amino group is completely trimethylated. The role of this modification is unknown. If the trimethylated lysine-43 plays some important role in the functioning, assembly or degradation of the c-ring, it would be expected to persist throughout vertebrates and possibly invertebrates also. Therefore, we have carried out a proteomic analysis of c-subunits across representative species from different classes of vertebrates and from invertebrate phyla. In the twenty-nine metazoan species that have been examined, the complete methylation of lysine-43 is conserved, and it is likely to be conserved throughout the more than two million extant metazoan species. In unicellular eukaryotes and prokaryotes, when the lysine is conserved it is unmethylated, and the stoichiometries of c-subunits vary from 9–15. One possible role for the trimethylated residue is to provide a site for the specific binding of cardiolipin, an essential component of ATP synthases in mitochondria. PMID:25608518

  1. Complex interactions between the laminin 4 subunit and integrins regulate endothelial cell behavior in vitro and angiogenesis in vivo

    NASA Astrophysics Data System (ADS)

    Gonzalez, Annette M.; Gonzales, Meredith; Herron, G. Scott; Nagavarapu, Usha; Hopkinson, Susan B.; Tsuruta, Daisuke; Jones, Jonathan C. R.

    2002-12-01

    The 4 laminin subunit is a component of the basement membrane of blood vessels where it codistributes with the integrins v3, 31, and 61. An antibody against the G domain (residues 919-1207; G919-1207) of the 4 laminin subunit inhibits angiogenesis in a mouse-human chimeric model, indicating the functional importance of this domain. Additional support for the latter derives from the ability of recombinant G919-1207 to support endothelial cell adhesion. In particular, endothelial cell adhesion to G919-1207 is half-maximal at 1.4 nM, whereas residues 919-1018 and 1016-1207 of the G domain are poor cellular ligands. Function blocking antibodies against integrins v3 and 1 and a combination of antibodies against 3 and α6 integrin subunits inhibit endothelial cell attachment to G919-1207. Moreover, both αvβ3 and α3β1 integrin bind with high affinity to G919-1207. Together, our studies demonstrate that the G domain of laminin α4 chain is a specific, high affinity ligand for the αvβ3 and α3β1 integrin heterodimers and that these integrins, together with α6β1, function cooperatively to mediate endothelial cell-α4 laminin interaction and hence blood vessel development. We propose a model based on these data that reconcile apparent discrepancies in the recent literature with regard to the role of the αvβ3 integrin in angiogenesis. matrix | matrix receptor | blood vessels

  2. Random matrix theory

    NASA Astrophysics Data System (ADS)

    Edelman, Alan; Rao, N. Raj

    Random matrix theory is now a big subject with applications in many disciplines of science, engineering and finance. This article is a survey specifically oriented towards the needs and interests of a numerical analyst. This survey includes some original material not found anywhere else. We include the important mathematics which is a very modern development, as well as the computational software that is transforming the theory into useful practice.

  3. Compact coverings for Baire locally convex spaces

    NASA Astrophysics Data System (ADS)

    Ka[Combining Cedilla]Kol, J.; Lopez Pellicer, M.

    2007-08-01

    Very recently Tkachuk has proved that for a completely regular Hausdorff space X the space Cp(X) of continuous real-valued functions on X with the pointwise topology is metrizable, complete and separable iff Cp(X) is Baire (i.e. of the second Baire category) and is covered by a family of compact sets such that K[alpha][subset of]K[beta] if [alpha][less-than-or-equals, slant][beta]. Our general result, which extends some results of De Wilde, Sunyach and Valdivia, states that a locally convex space E is separable metrizable and complete iff E is Baire and is covered by an ordered family of relatively countably compact sets. Consequently every Baire locally convex space which is quasi-Suslin is separable metrizable and complete.

  4. Compact fast analyzer of rotary cuvette type

    DOEpatents

    Thacker, Louis H.

    1976-01-01

    A compact fast analyzer of the rotary cuvette type is provided for simultaneously determining concentrations in a multiplicity of discrete samples using either absorbance or fluorescence measurement techniques. A rigid, generally rectangular frame defines optical passageways for the absorbance and fluorescence measurement systems. The frame also serves as a mounting structure for various optical components as well as for the cuvette rotor mount and drive system. A single light source and photodetector are used in making both absorbance and fluorescence measurements. Rotor removal and insertion are facilitated by a swing-out drive motor and rotor mount. BACKGROUND OF THE INVENTION The invention relates generally to concentration measuring instruments and more specifically to a compact fast analyzer of the rotary cuvette type which is suitable for making either absorbance or fluorescence measurements. It was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

  5. Compact Neutron Sources for Energy and Security

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Kobayashi, Hitoshi

    We choose nuclear data and nuclear material inspection for energy application, and nondestructive testing of explosive and hidden nuclear materials for security application. Low energy (~100 keV) electrostatic accelerators of deuterium are commercially available for nondestructive testing. For nuclear data measurement, electrostatic ion accelerators and L-band (1.428GHz) and S-band (2.856GHz) electron linear accelerators (linacs) are used for the neutron source. Compact or mobile X-band (9.3, 11.424GHz) electron linac neutron sources are under development. A compact proton linac neutron source is used for nondestructive testing, especially water in solids. Several efforts for more neutron intensity using proton and deuteron accelerators are also introduced.

  6. Compact Neutron Sources for Energy and Security

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Kobayashi, Hitoshi

    We choose nuclear data and nuclear material inspection for energy application, and nondestructive testing of explosive and hidden nuclear materials for security application. Low energy (˜100keV) electrostatic accelerators of deuterium are commercially available for nondestructive testing. For nuclear data measurement, electrostatic ion accelerators and L-band (1.428GHz) and S-band (2.856GHz) electron linear accelerators (linacs) are used for the neutron source. Compact or mobile X-band (9.3, 11.424GHz) electron linac neutron sources are under development. A compact proton linac neutron source is used for nondestructive testing, especially water in solids. Several efforts for more neutron intensity using proton and deuteron accelerators are also introduced.

  7. Acoustic Scattering from Compact Bubble Clouds.

    NASA Astrophysics Data System (ADS)

    Schindall, Jeffrey Alan

    In this study, a simple model describing the low -frequency scattering properties of high void fraction bubble clouds in both the free field and near the ocean surface is developed. This model, which is based on an effective medium approximation and acoustically compact scatters, successfully predicts the results of the bubble cloud scattering experiment carried out at Lake Seneca in New York state for frequencies consistent with the model assumptions (Roy et al., 1992). The introduction of the surface is facilitated by the method of images and is subject to the same constraint of low-acoustic frequency imposed by the compact scatterer assumption. This model is not intended to serve as an exact replicate of oceanic bubble cloud scattering. The model herein was kept simple by design, for only then can the complex physical behavior be expressed in a simple analytical form. Simple, analytic theories facilitate the exploration of parameter space, and more importantly serve to illuminate the underlying physics.

  8. The Atacama Compact Array: An Overview

    NASA Astrophysics Data System (ADS)

    Iguchi, S.; Wilson, T. L.

    2010-01-01

    When completed, ALMA will comprise a 12-meter diameter antennas array (12-m Array) of a minimum of fifty antennas, and the ACA (Atacama Compact Array), composed of four 12-meter diameter antennas and twelve 7-meter diameter antennas. Out of the fifty antennas of the 12-m Array, one-half are provided by the North American partners of ALMA, the other half by the European partners. The sixteen antennas that will comprise the ACA are provided by the East Asian Partners of ALMA. In the last issue of the ALMA Science Newsletter, we outlined the testing of the prototype ALMA 12-meter diameter antennas and the procurement process for these antennas. In that article, only a short account was given of the antennas for the Atacama Compact Array (ACA). In the following we give an overview of the ACA, starting with an introduction to imaging using interferometers.

  9. Compact dusty clouds in a cosmic environment

    SciTech Connect

    Tsytovich, V. N.; Ivlev, A. V.; Burkert, A.; Morfill, G. E.

    2014-01-10

    A novel mechanism of the formation of compact dusty clouds in astrophysical environments is discussed. It is shown that the balance of collective forces operating in space dusty plasmas can result in the effect of dust self-confinement, generating equilibrium spherical clusters. The distribution of dust and plasma density inside such objects and their stability are investigated. Spherical dusty clouds can be formed in a broad range of plasma parameters, suggesting that this process of dust self-organization might be a generic phenomenon occurring in different astrophysical media. We argue that compact dusty clouds can represent condensation seeds for a population of small-scale, cold, gaseous clumps in the diffuse interstellar medium. They could play an important role in regulating its small-scale structure and its thermodynamical evolution.

  10. Compact inductive energy storage pulse power system.

    PubMed

    K, Senthil; Mitra, S; Roy, Amitava; Sharma, Archana; Chakravarthy, D P

    2012-05-01

    An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.

  11. Chemical Abundances of Compact Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Lee, Ting-Hui; Shaw, Richard A.; Stanghellini, letizia; Riley, Ben

    2015-08-01

    We present preliminary results from an optical spectroscopic survey of compact planetary nebulae (PNe) in the Galactic disk. This is an ongoing optical+infrared spectral survey of 150 compact PNe to build a deep sample of PN chemical abundances. We obtained optical spectra of PNe with the Southern Astrophysical Research (SOAR) Telescope and Goodman High-Throughput Spectrograph between 2012 and 2015. These data were used to calculate the nebulae diagnostics such as electron temperature and density for each PN, and to derive the elemental abundances of He, N, O Ne, S and Ar. These abundances are vital to understanding the nature of the PNe, and their low- to intermediate-mass progenitor stars.

  12. RNA isolation and fractionation with compaction agents

    NASA Technical Reports Server (NTRS)

    Murphy, J. C.; Fox, G. E.; Willson, R. C.

    2001-01-01

    A new approach to the isolation of RNA from bacterial lysates employs selective precipitation by compaction agents, such as hexammine cobalt and spermidine. Using 3.5 mM hexammine cobalt, total RNA can be selectively precipitated from a cell lysate. At a concentration of 2 mM hexammine cobalt, rRNA can be fractionated from low molecular weight RNA. The resulting RNA mixture is readily resolved to pure 5S and mixed 16S/23S rRNA by nondenaturing anion-exchange chromatography. Using a second stage of precipitation at 8 mM hexammine cobalt, the low molecular weight RNA fraction can be isolated by precipitation. Compaction precipitation was also applied to the purification of an artificial stable RNA derived from Escherichia coli 5S rRNA and to the isolation of an Escherichia coli-expressed ribozyme. Copyright 2001 Academic Press.

  13. Rapid Compact Binary Coalescence Parameter Estimation

    NASA Astrophysics Data System (ADS)

    Pankow, Chris; Brady, Patrick; O'Shaughnessy, Richard; Ochsner, Evan; Qi, Hong

    2016-03-01

    The first observation run with second generation gravitational-wave observatories will conclude at the beginning of 2016. Given their unprecedented and growing sensitivity, the benefit of prompt and accurate estimation of the orientation and physical parameters of binary coalescences is obvious in its coupling to electromagnetic astrophysics and observations. Popular Bayesian schemes to measure properties of compact object binaries use Markovian sampling to compute the posterior. While very successful, in some cases, convergence is delayed until well after the electromagnetic fluence has subsided thus diminishing the potential science return. With this in mind, we have developed a scheme which is also Bayesian and simply parallelizable across all available computing resources, drastically decreasing convergence time to a few tens of minutes. In this talk, I will emphasize the complementary use of results from low latency gravitational-wave searches to improve computational efficiency and demonstrate the capabilities of our parameter estimation framework with a simulated set of binary compact object coalescences.

  14. Sequence Compaction to Preserve Transition Frequencies

    SciTech Connect

    Pinar, Ali; Liu, C.L.

    2002-12-12

    Simulation-based power estimation is commonly used for its high accuracy despite excessive computation times. Techniques have been proposed to speed it up by compacting an input sequence while preserving its power-consumption characteristics. We propose a novel method to compact a sequence that preserves transition frequencies. We prove the problem is NP-Complete, and propose a graph model to reduce it to that of finding a heaviest weighted trail on a directed graph, along with a heuristic utilizing this model. We also propose using multiple sequences for better accuracy with even shorter sequences. Experiments showed that power dissipation can be estimated with an error of only 2.3 percent, while simulation times are reduced by 10. Proposed methods effectively preserve transition frequencies and generated solutions that are very close to an optimal. Experiments also showed that multiple sequences granted more accurate results with even shorter sequences.

  15. Dynamics and function of compact nucleosome arrays.

    PubMed

    Poirier, Michael G; Oh, Eugene; Tims, Hannah S; Widom, Jonathan

    2009-09-01

    The packaging of eukaryotic DNA into chromatin sterically occludes polymerases, recombinases and repair enzymes. How chromatin structure changes to allow their actions is unknown. We constructed defined fluorescently labeled trinucleosome arrays, allowing analysis of chromatin conformational dynamics via fluorescence resonance energy transfer (FRET). The arrays undergo reversible Mg2+-dependent folding similar to that of longer arrays studied previously. We define two intermediate conformational states in the reversible folding of the nucleosome arrays and characterize the microscopic rate constants. Nucleosome arrays are highly dynamic even when compact, undergoing conformational fluctuations on timescales in the second to microsecond range. Compact states of the arrays allow binding to DNA within the central nucleosome via site exposure. Protein binding can also drive decompaction of the arrays. Thus, our results reveal multiple modes by which spontaneous chromatin fiber dynamics allow for the invasion and action of DNA-processing protein complexes.

  16. Metal Matrix Composites

    NASA Astrophysics Data System (ADS)

    Mortensen, Andreas; Llorca, Javier

    2010-08-01

    In metal matrix composites, a metal is combined with another, often nonmetallic, phase to produce a novel material having attractive engineering attributes of its own. A subject of much research in the 1980s and 1990s, this class of materials has, in the past decade, increased significantly in variety. Copper matrix composites, layered composites, high-conductivity composites, nanoscale composites, microcellular metals, and bio-derived composites have been added to a palette that, ten years ago, mostly comprised ceramic fiber- or particle-reinforced light metals together with some well-established engineering materials, such as WC-Co cermets. At the same time, research on composites such as particle-reinforced aluminum, aided by novel techniques such as large-cell 3-D finite element simulation or computed X-ray microtomography, has served as a potent vehicle for the elucidation of the mechanics of high-contrast two-phase elastoplastic materials, with implications that range well beyond metal matrix composites.

  17. Compact spectrometer system based on a gradient grating period guided-mode resonance filter.

    PubMed

    Lin, Hsin-An; Hsu, Hsin-Yun; Chang, Chih-Wei; Huang, Cheng-Sheng

    2016-05-16

    We demonstrate a compact spectrometer system by using a gradient grating period guided-mode resonance filter-mounted on a linear photodetector array-that exhibits spatially dependent resonance characteristics; a specific incident wavelength is reflected such that the underlying array pixels measure minimum intensity. A precalibrated transmission efficiency matrix is used to determine each pixel's transmission efficiency for specific wavelengths. Unknown spectral information can be calculated from the measured intensity. Grating periods of 250-388 nm in 2-nm increments are used in each 100-cycle period. Device length is 2.23 mm. Spectral range of 506-700 nm is measurable with 1-nm resolution.

  18. A compact cascaded microring filter with two master rings and two slave rings for sensing application

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Li, Zhi-quan; Tong, Kai

    2014-01-01

    In this paper, an ultra compact cascaded microring filter consisting of two master rings with radius of 2.5 μm and two slave rings with radius of 1 μm is presented and studied theoretically. The filter with a very large free spectral range (FSR) of 206 nm, a deep extinction ratio of 23 dB, a high quality factor of 2.76×105, and greatly suppressed spurious modes of less than 0.1 dB is achieved. The spectral responses of the filter are simulated by transfer matrix method, and the results show that this filter has a great potential of sensor application.

  19. Effects of cations and cosolvents on eukaryotic ribosomal subunit conformation

    SciTech Connect

    Moore, M.N.; Spremulli, L.L.

    1985-01-01

    The effects of various cations and cosolvents on the conformation of wheat germ ribosomes and ribosomal subunits have been investigated by using the techniques of circular dichroism and differential hydrogen exchange. A class of hydrogens on both the 40S and 60S subunits exchange out more rapidly as the Mg/sup 2 +/ concentration is raised, indicating that Mg/sup 2 +/ causes a change in subunit conformation. Ca/sup 2 +/ and the polyamines produce a similar increase in the rate of hydrogen exchange. These results suggest that increases in cation concentrations permit a tightening of ribosome structure and a greater degree of internalization of the rRNA. The cosolvent glycerol causes an alteration in the CD spectrum of 80S ribosomes in both the nucleic acid and protein portions of the spectrum. Glycerol also causes a decrease in the rate of exchange of a number of hydrogens on both the 40S and 60S subunits. These results are interpreted to mean that glycerol favors a more native, less denatured structure in the ribosome.

  20. The multifaceted subunit interfaces of ionotropic glutamate receptors.

    PubMed

    Green, Tim; Nayeem, Naushaba

    2015-01-01

    The past fifteen years has seen a revolution in our understanding of ionotropic glutamate receptor (iGluR) structure, starting with the first view of the ligand binding domain (LBD) published in 1998, and in many ways culminating in the publication of the full-length structure of GluA2 in 2009. These reports have revealed not only the central role played by subunit interfaces in iGluR function, but also myriad binding sites within interfaces for endogenous and exogenous factors. Changes in the conformation of inter-subunit interfaces are central to transmission of ligand gating into pore opening (itself a rearrangement of interfaces), and subsequent closure through desensitization. With the exception of the agonist binding site, which is located entirely within individual subunits, almost all modulatory factors affecting iGluRs appear to bind to sites in subunit interfaces. This review seeks to summarize what we currently understand about the diverse roles interfaces play in iGluR function, and to highlight questions for future research.

  1. The multifaceted subunit interfaces of ionotropic glutamate receptors.

    PubMed

    Green, Tim; Nayeem, Naushaba

    2014-06-06

    The past fifteen years has seen a revolution in our understanding of ionotropic glutamate receptor (iGluR) structure, starting with the first view of the ligand binding domain (LBD) published in 1998, and in many ways culminating in the publication of the full-length structure of GluA2 in 2009. These reports have revealed not only the central role played by subunit interfaces in iGluR function, but also myriad binding sites within interfaces for endogenous and exogenous factors. Changes in the conformation of inter-subunit interfaces are central to transmission of ligand gating into pore opening (itself a rearrangement of interfaces), and subsequent closure through desensitization. With the exception of the agonist binding site, which is located entirely within individual subunits, almost all modulatory factors affecting iGluRs appear to bind to sites in subunit interfaces. This review seeks to summarize what we currently understand about the diverse roles interfaces play in iGluR function, and to highlight questions for future research.

  2. Spectroscopic properties of Carcinus aestuarii hemocyanin and its structural subunits

    NASA Astrophysics Data System (ADS)

    Dolashka-Angelova, Pavlina; Hristova, Rumiyana; Stoeva, Stanka; Voelter, Wolfgang

    1999-12-01

    Hemocyanin (Hc) of Carcinus aestuarii contains three major and one minor electrophoretically separable polypeptide chains which were purified by fast protein liquid chromatography (FPLC) ion exchange chromatography. N-terminal amino acid sequences of four structural subunits (SSs) from C. aestuarii were compared with known N-terminal sequences from other arthropodan hemocyanins. The conformational changes, induced by various treatments, were monitored by far UV, CD and fluorescence spectroscopy. The critical temperatures for the structural subunits, Tc, determined by fluorescence spectroscopy, are in the region of 52-59°C and coincide with the melting temperatures, Tm (49-55°C), determined by CD spectroscopy. The free energy of stabilization in water, Δ GDH 2O , toward guanidinium hydrochloride is about 1.3 times higher for the dodecameric Hc as compared to the isolated subunits and about one time higher for Ca1, comparing with other SSs. The studies reveal that the conformational stability of the native dodecamer towards various denaturants (temperature and guanidinium hydrochloride) indicate that the quaternary structure is stabilized by oligomerization between structural subunits, and the possibility of a structural role of the sugar mojeties cannot be excluded.

  3. Emergence of ion channel modal gating from independent subunit kinetics

    PubMed Central

    Bicknell, Brendan A.

    2016-01-01

    Many ion channels exhibit a slow stochastic switching between distinct modes of gating activity. This feature of channel behavior has pronounced implications for the dynamics of ionic currents and the signaling pathways that they regulate. A canonical example is the inositol 1,4,5-trisphosphate receptor (IP3R) channel, whose regulation of intracellular Ca2+ concentration is essential for numerous cellular processes. However, the underlying biophysical mechanisms that give rise to modal gating in this and most other channels remain unknown. Although ion channels are composed of protein subunits, previous mathematical models of modal gating are coarse grained at the level of whole-channel states, limiting further dialogue between theory and experiment. Here we propose an origin for modal gating, by modeling the kinetics of ligand binding and conformational change in the IP3R at the subunit level. We find good agreement with experimental data over a wide range of ligand concentrations, accounting for equilibrium channel properties, transient responses to changing ligand conditions, and modal gating statistics. We show how this can be understood within a simple analytical framework and confirm our results with stochastic simulations. The model assumes that channel subunits are independent, demonstrating that cooperative binding or concerted conformational changes are not required for modal gating. Moreover, the model embodies a generally applicable principle: If a timescale separation exists in the kinetics of individual subunits, then modal gating can arise as an emergent property of channel behavior. PMID:27551100

  4. Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

    PubMed Central

    Römling, Ute; Galperin, Michael Y.

    2015-01-01

    Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

  5. ATP-induced helicase slippage reveals highly coordinated subunits

    NASA Astrophysics Data System (ADS)

    Wang, Michelle D.

    2012-02-01

    Helicases are vital enzymes that carry out strand separation of duplex nucleic acids during replication, repair and recombination. T7 helicase, a model hexameric motor, has been observed to use dTTP, but not ATP, to unwind dsDNA as it translocates along ssDNA. Whether and how different subunits of the helicase coordinate their chemo-mechanical activities and DNA binding during translocation is still under debate. Here we address this question using a single-molecule approach to monitor helicase unwinding. We found that T7 helicase does in fact unwind dsDNA in the presence of ATP and that the unwinding rate is even faster than that with dTTP. However, unwinding was repeatedly interrupted by sudden slippage events, ultimately preventing unwinding over a substantial distance. This behaviour was greatly reduced with the supplement of a small amount of dTTP. These findings presented an opportunity to use nucleotide mixtures to investigate helicase subunit coordination. Our results support a model where nearly all subunits coordinate their chemo-mechanical activities and DNA binding. Such subunit coordination may be general to many ring-shaped helicases and reveals a potential mechanism for regulation of DNA unwinding during replication.

  6. A World History Sub-Unit: Teaching about Turkey.

    ERIC Educational Resources Information Center

    Lynn, Karen

    This document is a sub-unit teaching plan for world history teachers who want to use multicultural concepts in the world history curriculum. The objective explored includes a student response to the Turkish question of "Who are we"? Teacher preparation involves defining social and cultural roots and outlining periods of Turkish history.…

  7. Compact Reconfigurable HF-UHF Antennas

    DTIC Science & Technology

    2007-11-02

    7] P. J. Rainville, F. J. Harackewiez, Magnetic Tuning of a Microstrip Patch Antenna Fabricated on a Ferrite Film, IEEE Microwave and Guided Wave...Letters, 1992, Vol. 2 pp. 483-5. [8] R. K. Misra, S. S. Pattnaik, N. Das, Tuning of Microstrip Antenna on Ferrite Substrate, IEEE Transactions on...DATES COVERED Final , 01 June 1999 to 31 Dec., 2003 4. TITLE AND SUBTITLE Compact Reconfigurable HF-UHF antennas 5. FUNDING

  8. Optimal Design of Compact Spur Gear Reductions

    DTIC Science & Technology

    1992-09-01

    stress, psi Lundberg and Palmgren (1952) developed a theory for the life and pressure angle, deg capacity of ball and roller bearings . This life model is... bearings (Lundberg and Paimgren, 1952). Lundberg and Palmgren determined that the scatter in the life of a bearing can be modeled with a two-parameter...optimal design of compact spur gear reductions includes the Vf unit gradient in the feasible direction selection of bearing and shaft proportions in

  9. VLA neutral hydrogen imaging of compact groups

    NASA Technical Reports Server (NTRS)

    Williams, B. A.; Mcmahon, P. M.; Vangorkom, J. H.

    1990-01-01

    Images of the neutral hydrogen (H I) in the direction of the compact groups of galaxies, HCG 31, HCG 44, and HCG 79 are presented. The authors find in HCG 31 and HCG 79, emission contained within a cloud much larger than the galaxies as well as the entire group. The H I emission associated with HCG 44 is located within the individual galaxies but shows definite signs of tidal interactions. The authors imaged the distribution and kinematics of neutral hydrogen at the two extremes of group sizes represented in Hickson's sample. HCG 44 is at the upper limit while HCG 18, HCG 31, and HCG 79 are at the lower end. Although the number of groups that have been imaged is still very small, there may be a pattern emerging which describes the H I morphology of compact groups. The true nature of compact groups has been the subject of considerable debate and controversy. The most recent observational and theoretical evidence strongly suggests that compact groups are physically dense, dynamical systems that are in the process of merging into a single object (Williams and Rood 1987, Hickson and Rood 1988, Barnes 1989). The neutral hydrogen deficiency observed by Williams and Rood (1987) is consistent with a model in which frequent galactic collisions and interactions have heated some of the gas during the short lifetime of the group. The H I disks which are normally more extended than the luminous ones are expected to be more sensitive to collisions and to trace the galaxy's response to recent interactions. Very Large Array observations can provide in most cases the spatial resolution needed to confirm the dynamical interactions in these systems.

  10. Compact 2-D graphical representation of DNA

    NASA Astrophysics Data System (ADS)

    Randić, Milan; Vračko, Marjan; Zupan, Jure; Novič, Marjana

    2003-05-01

    We present a novel 2-D graphical representation for DNA sequences which has an important advantage over the existing graphical representations of DNA in being very compact. It is based on: (1) use of binary labels for the four nucleic acid bases, and (2) use of the 'worm' curve as template on which binary codes are placed. The approach is illustrated on DNA sequences of the first exon of human β-globin and gorilla β-globin.

  11. Growing Magnetic Fields in Central Compact Objects

    NASA Astrophysics Data System (ADS)

    Bernal, C. G.; Page, D.

    2011-10-01

    We study the effects of growth models of magnetic fields in Central Compact Objects (CCOs). Such a field evolution is not a new idea (Blandford, Applegate, & Hernquist 1983) but the evolutionary implications not have been followed up completely (Michel 1994). We discussed the new class of neutron stars which belong to five main types that have mainly been recognized in the last ten years. The possibility that a rapid weakly magnetized pulsar might have formed in SN1987A is commented.

  12. Iterative solution of high order compact systems

    SciTech Connect

    Spotz, W.F.; Carey, G.F.

    1996-12-31

    We have recently developed a class of finite difference methods which provide higher accuracy and greater stability than standard central or upwind difference methods, but still reside on a compact patch of grid cells. In the present study we investigate the performance of several gradient-type iterative methods for solving the associated sparse systems. Both serial and parallel performance studies have been made. Representative examples are taken from elliptic PDE`s for diffusion, convection-diffusion, and viscous flow applications.

  13. Compact, Automated, Frequency-Agile Microspectrofluorimeter

    NASA Technical Reports Server (NTRS)

    Fernandez, Salvador M.; Guignon, Ernest F.

    1995-01-01

    Compact, reliable, rugged, automated cell-culture and frequency-agile microspectrofluorimetric apparatus developed to perform experiments involving photometric imaging observations of single live cells. In original application, apparatus operates mostly unattended aboard spacecraft; potential terrestrial applications include automated or semiautomated diagnosis of pathological tissues in clinical laboratories, biomedical instrumentation, monitoring of biological process streams, and portable instrumentation for testing biological conditions in various environments. Offers obvious advantages over present laboratory instrumentation.

  14. Compact quiescent galaxies at intermediate redshifts {sup ,}

    SciTech Connect

    Hsu, Li-Yen; Stockton, Alan; Shih, Hsin-Yi

    2014-12-01

    From several searches of the area common to the Sloan Digital Sky Survey and the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we have selected 22 luminous galaxies between z ∼ 0.4 and z ∼ 0.9 that have colors and sizes similar to those of the compact quiescent galaxies at z > 2. By exploring structural parameters and stellar populations, we found that most of these galaxies actually formed most of their stars at z < 2 and are generally less compact than those found at z > 2. Several of these young objects are disk-like or possibly prolate. This lines up with several previous studies that found that massive quiescent galaxies at high redshifts often have disk-like morphologies. If these galaxies were to be confirmed to be disk-like, their formation mechanism must be able to account for both compactness and disks. On the other hand, if these galaxies were to be confirmed to be prolate, the fact that prolate galaxies do not exist in the local universe would indicate that galaxy formation mechanisms have evolved over cosmic time. We also found five galaxies forming over 80% of their stellar masses at z > 2. Three of these galaxies appear to have been modified to have spheroid-like morphologies, in agreement with the scenario of 'inside-out' buildup of massive galaxies. The remaining galaxies, SDSS J014355.21+133451.4 and SDSS J115836.93+021535.1, have truly old stellar populations and disk-like morphologies. These two objects would be good candidates for nearly unmodified compact quiescent galaxies from high redshifts that are worth future study.

  15. Compaction Characteristics of Earth-Rock Mixtures

    DTIC Science & Technology

    1991-08-01

    position unless so designated by other authorized documents. The contents of this report are not to be used for advertising, publication, or...materials. In addition, these materials are " designed " as compacted fill by assessment of their properties through laboratory testing to establish fill...very sporadic and has mostly fallen to organizations engaged in regular major design and construction activities involving these materials such as the

  16. Light, Compact Pumper for Harbor Fires

    NASA Technical Reports Server (NTRS)

    Burns, R. A.

    1983-01-01

    Report describes development of new transportable water-pumping unit for fire-fighting. Compact, self-contained unit provides fire protection at coastal and inland ports and is lighter than standard firetruck pumper of same capacity. Used to fight fires in harbors, cities, forests, refineries, chemical plants, and offshore drilling platforms. Other possible applications include cleaning up oilspills, pumping out ships, and flood control pumping.

  17. Al Ager Water Compact Unit, Nassriya, Iraq

    DTIC Science & Technology

    2008-07-22

    plant was to contain a reverse osmosis unit, an above-ground storage reservoir, a pipe network connecting to the existing water network , and a...the existing water network , and a perimeter fence for the new facility. To date, the Al Ager Water Compact Unit project results are consistent with...of 110 millimeter (mm) polyvinyl chloride (PVC), connection to the existing water network , and a perimeter fence measuring approximately 50-m x 30-m

  18. Optical Omega network: a compact implementation technique

    NASA Astrophysics Data System (ADS)

    Wong, K. W.; Cheng, L. M.

    1995-10-01

    We propose a technique for the compact implementation of an optical Omega network. This technique utilizes the concept that both the perfect-shuffle interconnection and the switching stages can be realized by the same procedures, i.e., duplicate, shift, superimpose, and mask. As a result, a single set of optics is sufficient to realize the whole Omega network in a time-multiplexed recursive manner. Optical setups were designed and a proof-of-principle experiment was performed.

  19. Compact perturbative expressions for neutrino oscillations in matter

    DOE PAGES

    Denton, Peter B.; Minakata, Hisakazu; Parke, Stephen J.

    2016-06-08

    We further develop and extend a recent perturbative framework for neutrino oscillations in uniform matter density so that the resulting oscillation probabilities are accurate for the complete matter potential versus baseline divided by neutrino energy plane. This extension also gives the exact oscillation probabilities in vacuum for all values of baseline divided by neutrino energy. The expansion parameter used is related to the ratio of the solar to the atmosphericmore » $$\\Delta m^2$$ scales but with a unique choice of the atmospheric $$\\Delta m^2$$ such that certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using a mixing matrix formulation, this framework has the exceptional feature that the neutrino oscillation probability in matter has the same structure as in vacuum, to all orders in the expansion parameter. It also contains all orders in the matter potential and $$\\sin\\theta_{13}$$. It facilitates immediate physical interpretation of the analytic results, and makes the expressions for the neutrino oscillation probabilities extremely compact and very accurate even at zeroth order in our perturbative expansion. Furthermore, the first and second order results are also given which improve the precision by approximately two or more orders of magnitude per perturbative order.« less

  20. Flow-induced compaction of soft poroelastic materials

    NASA Astrophysics Data System (ADS)

    Nijjer, Japinder S.; Hewitt, Duncan R.; Worster, M. Grae; Neufeld, Jerome A.

    2016-11-01

    Fluid flows through poroelastic materials can result in solid deformation driven by the distribution of viscous shear stresses. The porosity and permeability of the solid matrix is altered spatially through a non-trivial coupling to the fluid flow. This behaviour is studied experimentally by examining fluid flow through a packing of soft hydrogel spheres driven by an imposed pressure head. The pressure head is varied, and, for each pressure, the steady-state mass flux and solid deformation are measured. For large pressure gradients, the fluid flow is found to decrease the permeability in such a way as to produce a flux that is independent of the applied pressure gradient. Measurements of the internal deformation, obtained by particle tracking, show that the medium compacts non-uniformly, with the porosity being lower at the outlet compared to the inlet. Intriguingly, we find a reproducible hysteresis of the poroelastic deformation between increasing and decreasing increments of the applied pressure head. The experimental results are compared to a simple one-dimensional model that accounts for non-linear elasticity of the solid and non-constant permeability.

  1. Sintering and foaming of barium silicate glass powder compacts

    NASA Astrophysics Data System (ADS)

    Mueller, Ralf; Reinsch, Stefan; Agea-Blanco, Boris

    2016-10-01

    The manufacture of sintered glasses and glass-ceramics, glass matrix composites and glass-bounded ceramics or pastes is often affected by gas bubble formation. Against this background, we studied sintering and foaming of barium silicate glass powders used as SOFC sealants using different powder milling procedures. Sintering was measured by means of heating microscopy backed up by XPD, DTA, Vacuum Hot Extraction (VHE) and optical and electron microscopy. Foaming increased significantly as milling progressed. For moderately milled glass powders, subsequent storage in air could also promote foaming. Although the powder compacts were uniaxially pressed and sintered in air, the milling atmosphere sig¬ni¬ficantly affected foaming. The strength of this effect increased in the order Ar ? N2 < air < CO2. Conformingly, VHE studies revealed that the pores of foamed samples predominantly encapsulated CO2, even for powders milled in Ar and N2. Results of this study thus indicate that foaming is caused by carbonaceous species trapped on the glass powder surface. Foaming could be substantially reduced by milling in water and 10 wt% HCl.

  2. Compact perturbative expressions for neutrino oscillations in matter

    SciTech Connect

    Denton, Peter B.; Minakata, Hisakazu; Parke, Stephen J.

    2016-06-08

    We further develop and extend a recent perturbative framework for neutrino oscillations in uniform matter density so that the resulting oscillation probabilities are accurate for the complete matter potential versus baseline divided by neutrino energy plane. This extension also gives the exact oscillation probabilities in vacuum for all values of baseline divided by neutrino energy. The expansion parameter used is related to the ratio of the solar to the atmospheric $\\Delta m^2$ scales but with a unique choice of the atmospheric $\\Delta m^2$ such that certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using a mixing matrix formulation, this framework has the exceptional feature that the neutrino oscillation probability in matter has the same structure as in vacuum, to all orders in the expansion parameter. It also contains all orders in the matter potential and $\\sin\\theta_{13}$. It facilitates immediate physical interpretation of the analytic results, and makes the expressions for the neutrino oscillation probabilities extremely compact and very accurate even at zeroth order in our perturbative expansion. Furthermore, the first and second order results are also given which improve the precision by approximately two or more orders of magnitude per perturbative order.

  3. Compact hybrid optoelectrical unit for image processing and recognition

    NASA Astrophysics Data System (ADS)

    Cheng, Gang; Jin, Guofan; Wu, Minxian; Liu, Haisong; He, Qingsheng; Yuan, ShiFu

    1998-07-01

    In this paper a compact opto-electric unit (CHOEU) for digital image processing and recognition is proposed. The central part of CHOEU is an incoherent optical correlator, which is realized with a SHARP QA-1200 8.4 inch active matrix TFT liquid crystal display panel which is used as two real-time spatial light modulators for both the input image and reference template. CHOEU can do two main processing works. One is digital filtering; the other is object matching. Using CHOEU an edge-detection operator is realized to extract the edges from the input images. Then the reprocessed images are sent into the object recognition unit for identifying the important targets. A novel template- matching method is proposed for gray-tome image recognition. A positive and negative cycle-encoding method is introduced to realize the absolute difference measurement pixel- matching on a correlator structure simply. The system has god fault-tolerance ability for rotation distortion, Gaussian noise disturbance or information losing. The experiments are given at the end of this paper.

  4. Compact and robust hyperspectral camera based on compressed sensing

    NASA Astrophysics Data System (ADS)

    Žídek, K.; Denk, O.; Hlubuček, J.; Václavík, J.

    2016-11-01

    Spectrum of light which is emitted or reflected by an object carries immense amount of information about the object. A simple piece of evidence is the importance of color sensing for human vision. Combining an image acquisition with efficient measurement of light spectra for each detected pixel is therefore one of the important issues in imaging, referred as hyperspectral imaging. We demonstrate a construction of a compact and robust hyperspectral camera for the visible and near-IR spectral region. The camera was designed vastly based on off-shelf optics, yet an extensive optimization and addition of three customized parts enabled construction of the camera featuring a low f-number (F/3.9) and fully concentric optics. We employ a novel approach of compressed sensing (namely coded aperture snapshot spectral imaging, abbrev. CASSI). The compressed sensing enables to computationally extract an encoded hyperspectral information from a single camera exposition. Owing to the technique the camera lacks any moving or scanning part, while it can record the full image and spectral information in a single snapshot. Moreover, unlike the commonly used compressed sensing table-top apparatuses, the camera represents a portable device able to work outside a lab. We demonstrate the spectro-temporal reconstruction of recorded scenes based on 90×90 random matrix encoding. Finally, we discuss potential of the compressed sensing in hyperspectral camera.

  5. Glycoprotein hormone assembly in the endoplasmic reticulum: I. The glycosylated end of human alpha-subunit loop 2 is threaded through a beta-subunit hole.

    PubMed

    Xing, Yongna; Myers, Rebecca V; Cao, Donghui; Lin, Win; Jiang, Mei; Bernard, Michael P; Moyle, William R

    2004-08-20

    Glycoprotein hormone heterodimers are stabilized by their unusual structures in which a glycosylated loop of the alpha-subunit straddles a hole in the beta-subunit. This hole is formed when a cysteine at the end of a beta-subunit strand known as the "seatbelt" becomes "latched" by a disulfide to a cysteine in the beta-subunit core. The heterodimer is stabilized in part by the difficulty of threading the glycosylated end of the alpha-subunit loop 2 through this hole, a phenomenon required for subunit dissociation. Subunit combination in vitro, which occurs by the reverse process, can be accelerated by removing the alpha-subunit oligosaccharide. In cells, heterodimer assembly was thought to occur primarily by a mechanism in which the seatbelt is wrapped around the alpha-subunit after the subunits dock. Here we show that this "wraparound" process can be used to assemble disulfide cross-linked human choriogonadotropin analogs that contain an additional alpha-subunit cysteine, but only if the normal beta-subunit latch site has been removed. Normally, the seatbelt is latched before the subunits dock and assembly is completed when the glycosylated end of alpha-subunit loop 2 is threaded beneath the seatbelt. The unexpected finding that most assembly of human choriogonadotropin, human follitropin, and human thyrotropin heterodimers occurs in this fashion, indicates that threading may be an important phenomenon during protein folding and macromolecule assembly in the endoplasmic reticulum. We suggest that the unusual structures of the glycoprotein hormones makes them useful for identifying factors that influence this process in living cells.

  6. Infiltration tests on fractured compacted clay

    SciTech Connect

    McBrayer, M.C.; Mauldon, M.; Drumm, E.C.; Wilson, G.V.

    1997-05-01

    Desiccation and freeze-thaw of compacted clay barriers may result in cracks that serve as preferential flow paths. A series of infiltration tests on compacted kaolin samples was conducted to explore the importance of preferential flow paths during infiltration, and their effect on the infiltration rate. Clod size at the time of compaction was found to have a strong influence on both the rate and depth of infiltration. The authors suggest that flow and infiltration through fractured clay may be described in terms of two stages: an initial dynamic stage in which the infiltration rate is initially high but decreases rapidly due to the clay swelling and closing fractures, and a steady-state stage usually characterized by k{sub sat}, during which the infiltration rate is relatively constant. The study has shown that cracks do not fully heal upon hydration and readily reopen during subsequent dehydration. Infiltration rates during the dynamic stage of infiltration, while cracks are closing, are orders of magnitude higher than the steady-state rate used to estimate k{sub sat}, for barrier evaluation.

  7. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2014-01-01

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  8. Differentiation and compaction in the Skaergaard intrusion

    NASA Astrophysics Data System (ADS)

    Tegner, C.; Thy, P.; Holness, M.; Jakobsen, J. K.; Salmonsen, L.; Humphreys, M.; Lesher, C. E.

    2009-12-01

    Although it is largely agreed that crystallization occurs inwardly in crystal mushes along the margins of magma chambers, the efficiency and mechanisms of differentiation are contended. The fractionation paradigm hinges on mass exchange between a crystal mush and the main magma reservoir resulting in coarse-grained, refractory (cumulate) rocks of primary crystals, and complementary enrichment of incompatible elements in the main magma. Diffusion, convection, liquid immiscibility and compaction have been proposed as mechanisms driving this mass exchange. We examine the efficiency of differentiation in basaltic crystal mushes of the Skaergaard magma chamber. The contents of incompatible elements such as phosphorus and calculated final porosities are smallest in cumulate rocks at the floor (~5% final porosity above the level of magnetite-in), intermediate at the walls (~20%) and highest at the roof (~55%). Mass exchange and differentiation are thus highly efficient at the floor but inefficient at the roof. This is best explained by compaction squeezing interstitial liquid out of the crystal mush preferentially at the floor. At the walls only mush with porosity less than ~20% was able to stick rather than collapsing into the chamber, resulting in moderately efficient differentiation. We conclude that compaction moderates the final crystal mush porosity and the efficiency of magma differentiation depending on chamber dynamics.

  9. Electrothermal Defect Detection in Powder Metallurgy Compacts

    NASA Astrophysics Data System (ADS)

    Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

    2006-03-01

    Faced with increasing market pressures, metal part manufacturers have turned to new processes and fabrication technologies. One of these processes is powder metallurgy (P/M), which is employed for low-cost, high-volume precision part manufacturing. Despite many advantages, the P/M process has created a number of challenges, including the need for high-speed quality assessment and control, ideally for each compact. Consequently, sophisticated quality assurance is needed to rapidly detect flaws early in the manufacturing cycle and at minimal cost. In this paper we will discuss our progress made in designing and refining an active infrared (IR) detection system for P/M compacts. After discussing the theoretical background in terms of underlying equations and boundary conditions, analytical and numerical solutions are presented that are capable of predicting temperature responses for various defect sizes and orientations of a dynamic IR testing system. Preliminary measurements with controlled and industrial samples have shown that this active IR methodology can successfully be employed to test both green-state and sintered P/M compacts. The developed system can overcome many limitations observed with a standard IR testing methodology such as emissivity, background calibration, and contact resistance.

  10. Compact Stellar X-ray Sources

    NASA Astrophysics Data System (ADS)

    Lewin, Walter H. G.; van der Klis, Michiel

    2006-04-01

    1. Accreting neutron stars and black holes: a decade of discoveries D. Psaltis; 2. Rapid X-ray variability M. van der Klis; 3. New views of thermonuclear bursts T. Strohmayer and L. Bildsten; 4. Black hole binaries J. McClintock and R. Remillard; 5. Optical, ultraviolet and infrared observations of X-ray binaries P. Charles and M. Coe; 6. Fast X-ray transients and X-ray flashes J. Heise and J. in 't Zand; 7. Isolated neutron stars V. Kaspi, M. Roberts and A. Harding; 8. Globular cluster X-ray sources F. Verbunt and W. Lewin; 9. Jets from X-ray binaries R. Fender; 10. X-Rays from cataclysmic variables E. Kuulkers, A. Norton, A. Schwope and B. Warner; 11. Super soft sources P. Kahabka and E. van den Heuvel; 12. Compact stellar X-ray sources in normal galaxies G. Fabbiano and N. White; 13. Accretion in compact binaries A. King; 14. Soft gamma repeaters and anomalous X-ray pulsars: magnetar candidates P. Woods and C. Thompson; 15. Cosmic gamma-ray bursts, their afterglows, and their host galaxies K. Hurley, R. Sari and S. Djorgovski; 16. Formation and evolution of compact stellar X-ray sources T. Tauris and E. van den Heuvel.

  11. Compact Stellar X-ray Sources

    NASA Astrophysics Data System (ADS)

    Lewin, Walter; van der Klis, Michiel

    2010-11-01

    1. Accreting neutron stars and black holes: a decade of discoveries D. Psaltis; 2. Rapid X-ray variability M. van der Klis; 3. New views of thermonuclear bursts T. Strohmayer and L. Bildsten; 4. Black hole binaries J. McClintock and R. Remillard; 5. Optical, ultraviolet and infrared observations of X-ray binaries P. Charles and M. Coe; 6. Fast X-ray transients and X-ray flashes J. Heise and J. in 't Zand; 7. Isolated neutron stars V. Kaspi, M. Roberts and A. Harding; 8. Globular cluster X-ray sources F. Verbunt and W. Lewin; 9. Jets from X-ray binaries R. Fender; 10. X-Rays from cataclysmic variables E. Kuulkers, A. Norton, A. Schwope and B. Warner; 11. Super soft sources P. Kahabka and E. van den Heuvel; 12. Compact stellar X-ray sources in normal galaxies G. Fabbiano and N. White; 13. Accretion in compact binaries A. King; 14. Soft gamma repeaters and anomalous X-ray pulsars: magnetar candidates P. Woods and C. Thompson; 15. Cosmic gamma-ray bursts, their afterglows, and their host galaxies K. Hurley, R. Sari and S. Djorgovski; 16. Formation and evolution of compact stellar X-ray sources T. Tauris and E. van den Heuvel.

  12. Design of optics for compact star sensors

    NASA Astrophysics Data System (ADS)

    Xu, Minyi; Shi, Rongbao; Shen, Weimin

    2016-10-01

    In order to adapt to small size and low cost space platform such as mini-satellites, this paper studies the design of optics for compact star sensor. At first, the relationship between limiting magnitude and optical system specifications which includes field of view and entrance pupil diameter is analyzed, based on its Pyramid identification algorithm and signal-to-noise ratio requirement. The specifications corresponding to different limiting magnitude can be obtained after the detector is selected, and both of the complexity of optical lens and the size of baffle can be estimated. Then the range of the limiting magnitude can be determined for the miniaturization of the optical system. Taking STAR1000 CMOS detector as an example, the compact design of the optical system can be realized when the limiting magnitude is in the interval of 4.9Mv 5.5Mv. At last, the lens and baffle of a CMOS compact star sensor is optimally designed, of which length and weight is respectively 124 millimeters and 300 grams.

  13. Compact x-ray source and panel

    SciTech Connect

    Sampayon, Stephen E.

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  14. Evaluating quantitative 3-D image analysis as a design tool for low enriched uranium fuel compacts for the transient reactor test facility: A preliminary study

    SciTech Connect

    Kane, J. J.; van Rooyen, I. J.; Craft, A. E.; Roney, T. J.; Morrell, S. R.

    2016-02-05

    In this study, 3-D image analysis when combined with a non-destructive examination technique such as X-ray computed tomography (CT) provides a highly quantitative tool for the investigation of a material’s structure. In this investigation 3-D image analysis and X-ray CT were combined to analyze the microstructure of a preliminary subsized fuel compact for the Transient Reactor Test Facility’s low enriched uranium conversion program to assess the feasibility of the combined techniques for use in the optimization of the fuel compact fabrication process. The quantitative image analysis focused on determining the size and spatial distribution of the surrogate fuel particles and the size, shape, and orientation of voids within the compact. Additionally, the maximum effect of microstructural features on heat transfer through the carbonaceous matrix of the preliminary compact was estimated. The surrogate fuel particles occupied 0.8% of the compact by volume with a log-normal distribution of particle sizes with a mean diameter of 39 μm and a standard deviation of 16 μm. Roughly 39% of the particles had a diameter greater than the specified maximum particle size of 44 μm suggesting that the particles agglomerate during fabrication. The local volume fraction of particles also varies significantly within the compact although uniformities appear to be evenly dispersed throughout the analysed volume. The voids produced during fabrication were on average plate-like in nature with their major axis oriented perpendicular to the compaction direction of the compact. Finally, the microstructure, mainly the large preferentially oriented voids, may cause a small degree of anisotropy in the thermal diffusivity within the compact. α∥/α⊥, the ratio of thermal diffusivities parallel to and perpendicular to the compaction direction are expected to be no less than 0.95 with an upper bound of 1.

  15. Evaluating quantitative 3-D image analysis as a design tool for low enriched uranium fuel compacts for the transient reactor test facility: A preliminary study

    DOE PAGES

    Kane, J. J.; van Rooyen, I. J.; Craft, A. E.; ...

    2016-02-05

    In this study, 3-D image analysis when combined with a non-destructive examination technique such as X-ray computed tomography (CT) provides a highly quantitative tool for the investigation of a material’s structure. In this investigation 3-D image analysis and X-ray CT were combined to analyze the microstructure of a preliminary subsized fuel compact for the Transient Reactor Test Facility’s low enriched uranium conversion program to assess the feasibility of the combined techniques for use in the optimization of the fuel compact fabrication process. The quantitative image analysis focused on determining the size and spatial distribution of the surrogate fuel particles andmore » the size, shape, and orientation of voids within the compact. Additionally, the maximum effect of microstructural features on heat transfer through the carbonaceous matrix of the preliminary compact was estimated. The surrogate fuel particles occupied 0.8% of the compact by volume with a log-normal distribution of particle sizes with a mean diameter of 39 μm and a standard deviation of 16 μm. Roughly 39% of the particles had a diameter greater than the specified maximum particle size of 44 μm suggesting that the particles agglomerate during fabrication. The local volume fraction of particles also varies significantly within the compact although uniformities appear to be evenly dispersed throughout the analysed volume. The voids produced during fabrication were on average plate-like in nature with their major axis oriented perpendicular to the compaction direction of the compact. Finally, the microstructure, mainly the large preferentially oriented voids, may cause a small degree of anisotropy in the thermal diffusivity within the compact. α∥/α⊥, the ratio of thermal diffusivities parallel to and perpendicular to the compaction direction are expected to be no less than 0.95 with an upper bound of 1.« less

  16. In situ strengths of matrix in a composite

    NASA Astrophysics Data System (ADS)

    Huang, Zheng-Ming; Xin, Li-Min

    2017-02-01

    A major obstacle to achieving reasonable strength prediction of a composite only from its constituent information is in the determination of in situ strengths of the matrix. One can measure only the original strengths of the pure matrix, on the basis of which the predicted transverse strengths of a unidirectional (UD) composite are far from reality. It is impossible to reliably measure matrix in situ strengths. This paper focuses on the correlation between in situ and original strengths. Stress concentrations in a matrix owing to the introduction of fibers are attributed to the strength variation. Once stress concentration factors (SCFs) are obtained, the matrix in situ strengths are assigned as the original counterparts divided by them. Such an SCF cannot be defined following a classical approach. All of the relevant issues associated with determining it are systematically addressed in this paper. Analytical expressions for SCFs under transverse tension, transverse compression, and transverse shear are derived. Closed-form and compact formulas for all of the uniaxial strengths of a UD composite are first presented in this paper. Their application to strength predictions of a number of typical UD composites demonstrates the correctness of these formulas.

  17. Generation and enumeration of compact conformations on the two-dimensional triangular and three-dimensional fcc lattices

    NASA Astrophysics Data System (ADS)

    Peto, Myron; Sen, Taner Z.; Jernigan, Robert L.; Kloczkowski, Andrzej

    2007-07-01

    We enumerated all compact conformations within simple geometries on the two-dimensional (2D) triangular and three-dimensional (3D) face centered cubic (fcc) lattice. These compact conformations correspond mathematically to Hamiltonian paths and Hamiltonian circuits and are frequently used as simple models of proteins. The shapes that were studied for the 2D triangular lattice included m ×n parallelograms, regular equilateral triangles, and various hexagons. On the 3D fcc lattice we generated conformations for a limited class of skewed parallelepipeds. Symmetries of the shape were exploited to reduce the number of conformations. We compared surface to volume ratios against protein length for compact conformations on the 3D cubic lattice and for a selected set of real proteins. We also show preliminary work in extending the transfer matrix method, previously developed by us for the 2D square and the 3D cubic lattices, to the 2D triangular lattice. The transfer matrix method offers a superior way of generating all conformations within a given geometry on a lattice by completely avoiding attrition and reducing this highly complicated geometrical problem to a simple algebraic problem of matrix multiplication.

  18. Binding interactions with the complementary subunit of nicotinic receptors.

    PubMed

    Blum, Angela P; Van Arnam, Ethan B; German, Laurel A; Lester, Henry A; Dougherty, Dennis A

    2013-03-08

    The agonist-binding site of nicotinic acetylcholine receptors (nAChRs) spans an interface between two subunits of the pentameric receptor. The principal component of this binding site is contributed by an α subunit, and it binds the cationic moiety of the nicotinic pharmacophore. The other part of the pharmacophore, a hydrogen bond acceptor, has recently been shown to bind to the complementary non-α subunit via the backbone NH of a conserved Leu. This interaction was predicted by studies of ACh-binding proteins and confirmed by functional studies of the neuronal (CNS) nAChR, α4β2. The ACh-binding protein structures further suggested that the hydrogen bond to the backbone NH is mediated by a water molecule and that a second hydrogen bonding interaction occurs between the water molecule and the backbone CO of a conserved Asn, also on the non-α subunit. Here, we provide new insights into the nature of the interactions between the hydrogen bond acceptor of nicotinic agonists and the complementary subunit backbone. We studied both the nAChR of the neuromuscular junction (muscle-type) and a neuronal subtype, (α4)2(β4)3. In the muscle-type receptor, both ACh and nicotine showed a strong interaction with the Leu NH, but the potent nicotine analog epibatidine did not. This interaction was much attenuated in the α4β4 receptor. Surprisingly, we found no evidence for a functionally significant interaction with the backbone carbonyl of the relevant Asn in either receptor with an array of agonists.

  19. The centromere-kinetochore complex: a repeat subunit model

    PubMed Central

    1991-01-01

    The three-dimensional structure of the kinetochore and the DNA/protein composition of the centromere-kinetochore region was investigated using two novel techniques, caffeine-induced detachment of unreplicated kinetochores and stretching of kinetochores by hypotonic and/or shear forces generated in a cytocentrifuge. Kinetochore detachment was confirmed by EM and immunostaining with CREST autoantibodies. Electron microscopic analyses of serial sections demonstrated that detached kinetochores represented fragments derived from whole kinetochores. This was especially evident for the seven large kinetochores in the male Indian muntjac that gave rise to 80-100 fragments upon detachment. The kinetochore fragments, all of which interacted with spindle microtubules and progressed through the entire repertoire of mitotic movements, provide evidence for a subunit organization within the kinetochore. Further support for a repeat subunit model was obtained by stretching or uncoiling the metaphase centromere-kinetochore complex by hypotonic treatments. When immunostained with CREST autoantibodies and subsequently processed for in situ hybridization using synthetic centromere probes, stretched kinetochores displayed a linear array of fluorescent subunits arranged in a repetitive pattern along a centromeric DNA fiber. In addition to CREST antigens, each repetitive subunit was found to bind tubulin and contain cytoplasmic dynein, a microtubule motor localized in the zone of the corona. Collectively, the data suggest that the kinetochore, a plate-like structure seen by EM on many eukaryotic chromosomes is formed by the folding of a linear DNA fiber consisting of tandemly repeated subunits interspersed by DNA linkers. This model, unlike any previously proposed, can account for the structural and evolutional diversity of the kinetochore and its relationship to the centromere of eukaryotic chromosomes of many species. PMID:1828250

  20. Expression of glutamate receptor subunits in human cancers.

    PubMed

    Stepulak, Andrzej; Luksch, Hella; Gebhardt, Christine; Uckermann, Ortrud; Marzahn, Jenny; Sifringer, Marco; Rzeski, Wojciech; Staufner, Christian; Brocke, Katja S; Turski, Lechoslaw; Ikonomidou, Chrysanthy

    2009-10-01

    Emerging evidence suggests a role for glutamate and its receptors in the biology of cancer. This study was designed to systematically analyze the expression of ionotropic and metabotropic glutamate receptor subunits in various human cancer cell lines, compare expression levels to those in human brain tissue and, using electrophysiological techniques, explore whether cancer cells respond to glutamate receptor agonists and antagonists. Expression analysis of glutamate receptor subunits NR1-NR3B, GluR1-GluR7, KA1, KA2 and mGluR1-mGluR8 was performed by means of RT-PCR in human rhabdomyosarcoma/medulloblastoma (TE671), neuroblastoma (SK-NA-S), thyroid carcinoma (FTC 238), lung carcinoma (SK-LU-1), astrocytoma (MOGGCCM), multiple myeloma (RPMI 8226), glioma (U87-MG and U343), lung carcinoma (A549), colon adenocarcinoma (HT 29), T cell leukemia cells (Jurkat E6.1), breast carcinoma (T47D) and colon adenocarcinoma (LS180). Analysis revealed that all glutamate receptor subunits were differentially expressed in the tumor cell lines. For the majority of tumors, expression levels of NR2B, GluR4, GluR6 and KA2 were lower compared to human brain tissue. Confocal imaging revealed that selected glutamate receptor subunit proteins were expressed in tumor cells. By means of patch-clamp analysis, it was shown that A549 and TE671 cells depolarized in response to application of glutamate agonists and that this effect was reversed by glutamate receptor antagonists. This study reveals that glutamate receptor subunits are differentially expressed in human tumor cell lines at the mRNA and the protein level, and that their expression is associated with the formation of functional channels. The potential role of glutamate receptor antagonists in cancer therapy is a feasible goal to be explored in clinical trials.

  1. Targeting signals and subunit interactions in coated vesicle adaptor complexes

    PubMed Central

    1995-01-01

    There are two clathrin-coated vesicle adaptor complexes in the cell, one associated with the plasma membrane and one associated with the TGN. The subunit composition of the plasma membrane adaptor complex is alpha-adaptin, beta-adaptin, AP50, and AP17; while that of the TGN adaptor complex is gamma-adaptin, beta'-adaptin, AP47, and AP19. To search for adaptor targeting signals, we have constructed chimeras between alpha-adaptin and gamma-adaptin within their NH2-terminal domains. We have identified stretches of sequence in the two proteins between amino acids approximately 130 and 330-350 that are essential for targeting. Immunoprecipitation reveals that this region determines whether a construct coassemblies with AP50 and AP17, or with AP47 and AP19. These observations suggest that these other subunits may play an important role in targeting. In contrast, beta- and beta'-adaptins are clearly not involved in this event. Chimeras between the alpha- and gamma-adaptin COOH-terminal domains reveal the presence of a second targeting signal. We have further investigated the interactions between the adaptor subunits using the yeast two-hybrid system. Interactions can be detected between the beta/beta'-adaptins and the alpha/gamma- adaptins, between the beta/beta'-adaptins and the AP50/AP47 subunits, between alpha-adaptin and AP17, and between gamma-adaptin and AP19. These results indicate that the adaptor subunits act in concert to target the complex to the appropriate membrane. PMID:7593184

  2. Heterotrimeric G protein subunit Gγ13 is critical to olfaction

    PubMed Central

    Li, Feng; Ponissery-Saidu, Samsudeen; Yee, Karen; Wang, Hong; Chen, Meng-Ling; Iguchi, Naoko; Zhang, Genhua; Jiang, Ping; Reisert, Johannes; Huang, Liquan

    2013-01-01

    The activation of G-protein-coupled olfactory receptors on the olfactory sensory neurons (OSNs) triggers a signaling cascade, which is mediated by a heterotrimeric G protein consisting of α, β and γ subunits. Although its α subunit, Gαolf, has been identified and well characterized, the identities of its β and γ subunits and their function in olfactory signal transduction, however, have not been well established yet. We and others have found the expression of Gγ13 in the olfactory epithelium, particularly in the cilia of the OSNs. In this study, we generated a conditional gene knockout mouse line to specifically nullify Gγ13 expression in the olfactory marker protein-expressing OSNs. Immunohistochemical and Western blot results showed that Gγ13 subunit was indeed eliminated in the mutant mice’s olfactory epithelium. Intriguingly, Gαolf, β1 subunits, Ric-8B and CEP290 proteins were also absent in the epithelium whereas the presence of the effector enzyme adenylyl cyclase III remained largely unaltered. Electro-olfactogram studies showed that the mutant animals had greatly reduced responses to a battery of odorants including three presumable pheromones. Behavioral tests indicated that the mutant mice had a remarkably reduced ability to perform an odor-guided search task although their motivation and agility seemed normal. Our results indicate that Gαolf exclusively forms a functional heterotrimeric G protein with Gβ1 and Gγ13 in OSNs, mediating olfactory signal transduction. The identification of the olfactory G protein’s βγ moiety has provided a novel approach to understanding the feedback regulation of olfactory signal transduction pathways as well as the control of subcellular structures of OSNs. PMID:23637188

  3. Sharp Estimates in Ruelle Theorems for Matrix Transfer Operators

    NASA Astrophysics Data System (ADS)

    Campbell, J.; Latushkin, Y.

    A matrix coefficient transfer operator , on the space of -sections of an m-dimensional vector bundle over n-dimensional compact manifold is considered. The spectral radius of is estimated bya; and the essential spectral radius by Here is the set of ergodic f-invariant measures, and for is the measure-theoretic entropy of f, is the largest Lyapunov exponent of the cocycle over f generated by , and is the smallest Lyapunov exponent of the differential of f.

  4. On the Matrix Exponential Function

    ERIC Educational Resources Information Center

    Hou, Shui-Hung; Hou, Edwin; Pang, Wan-Kai

    2006-01-01

    A novel and simple formula for computing the matrix exponential function is presented. Specifically, it can be used to derive explicit formulas for the matrix exponential of a general matrix A satisfying p(A) = 0 for a polynomial p(s). It is ready for use in a classroom and suitable for both hand as well as symbolic computation.

  5. Roll compaction of mannitol: compactability study of crystalline and spray-dried grades.

    PubMed

    Wagner, Carl Moritz; Pein, Miriam; Breitkreutz, Jörg

    2013-09-10

    Purpose of this project was to investigate the roll compaction behavior of various mannitol grades. Therefore, five spray-dried grades as well as unprocessed β-d-mannitol were roll compacted with different compaction forces. The resulting granules were characterized with regard to their particle size distribution, flow properties, and BET surface area and compressed to tablets. Granules of unprocessed mannitol, even when applying high compaction forces during dry granulation, were characterized by a high amount of fines (about 21%), a small surface area (0.83 m(2)/g), and solely fair flowability (ffc=7.2). Tablets revealed either high friability or insufficient disintegration behavior. However, the use of spray-dried mannitol led to better results. Granules showed improved flow properties and a reduced amount of fines. Robust tablets with low friability were produced. Within the various spray-dried grades huge differences concerning the compactability were observed. Large BET surface areas of the granules resulted in advanced tensile strengths of the tablets, but acceptable disintegration behavior was maintained. These findings are relevant for the development of mannitol based drug formulations, in particular (oro)dispersible tablets containing a low dose or poor flowing active pharmaceutical ingredient, where direct compression is inappropriate and a granulation process prior to tableting is mandatory.

  6. Investigation on the Thermal Crack Evolution and Oxidation Effect of Compacted Graphite Iron Under Thermal Shock

    NASA Astrophysics Data System (ADS)

    Wang, Xiaosong; Zhang, Weizheng; Guo, Bingbin

    2015-09-01

    For a better understanding of the thermal fatigue behavior in compacted graphite cast iron (CGI), the cyclic thermal shock test is carried out through alternating induction heating and water quenching. The optical and scanning electron microscopy observations are used to examine the cracks and oxidation behavior on the cross section and heating surface of the material specimen, respectively. The results show that the thermal cracks in CGI initiate at the graphite phases mostly, and the multi-sourced thermal cracks would result in stable cracks morphology finally through crack shielding effect. In the oxidation analysis, it is found that the oxidation of graphite is selective, and the graphite is the potential channels for oxygen diffusion from the outside into the matrix, resulting in local oxidation of matrix around graphite and continuous oxygen diffusion paths in the microstructure. Thermal cracks nucleate from the oxidation holes at graphite caused by decarburization, and they prefer to propagate and coalesce by penetrating the oxide bridges.

  7. Characterisation of a BC501A compact neutron spectrometer for fusion research

    NASA Astrophysics Data System (ADS)

    Tardini, G.; Gagnon-Moisan, F.; Zimbal, A.

    2016-10-01

    The compact neutron spectrometer used at the ASDEX Upgrade tokamak is characterised to obtain its response matrix. This paper describes the characterisation procedure and the derived response matrix, based on a campaign at the PTB ion accelerator facility (PIAF) and on the subsequent time-of-flight (TOF) analysis of neutrons from a field with a broad energy distribution. The response of mono-energetic neutrons generated at the PIAF is used as reference for the TOF analysis. The detector's response functions for spectrum deconvolution are obtained by Gaussian broadening of the simulated responses to fit the experimental ones, using a maximum-entropy ansatz. In this way, the response functions are smooth enough to ensure a reliable unfolding of pulse height spectra into neutron emission spectra, which provide information on the fast ion velocity distribution in neutral beam heated tokamak plasmas.

  8. Summary Report for the Initiation of Compact Development for Particles with 425-micron Kernels

    SciTech Connect

    Pappano, Peter J

    2007-09-01

    The purpose of this research was the initiation of overcoating TRISO particles with 425 {micro}m kernels. In the AGR-1 task, the overcoating process was optimized for particles with an outer diameter (OD) of 780 {micro}m and a 350 {micro}m kernel. Therefore it needed to be determined how well the overcoating process used to fabricate AGR-1 compacts would perform on particles with an 855 {micro}m OD and a 425 {micro}m kernel. The matrix properties and overcoating procedures were altered from the AGR-1 processes in order to attempt to optimize the overcoating of TRISO particles with 425 {micro}m kernels. This report summarizes the changes that were made to the matrix and the overcoating process in order to achieve successful overcoating of the larger particles.

  9. The cellulose resource matrix.

    PubMed

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  10. The MUC1 Extracellular Domain Subunit Is Found in Nuclear Speckles and Associates with Spliceosomes

    PubMed Central

    Kumar, Priyadarsina; Ji, Jennifer W.; Martsching, Lindsay; Douglas, Gordon C.

    2012-01-01

    MUC1 is a large transmembrane glycoprotein and oncogene expressed by epithelial cells and overexpressed and underglycosylated in cancer cells. The MUC1 cytoplasmic subunit (MUC1-C) can translocate to the nucleus and regulate gene expression. It is frequently assumed that the MUC1 extracellular subunit (MUC1-N) does not enter the nucleus. Based on an unexpected observation that MUC1 extracellular domain antibody produced an apparently nucleus-associated staining pattern in trophoblasts, we have tested the hypothesis that MUC1-N is expressed inside the nucleus. Three different antibodies were used to identify MUC1-N in normal epithelial cells and tissues as well as in several cancer cell lines. The results of immunofluorescence and confocal microscopy analyses as well as subcellular fractionation, Western blotting, and siRNA/shRNA studies, confirm that MUC1-N is found within nuclei of all cell types examined. More detailed examination of its intranuclear distribution using a proximity ligation assay, subcellular fractionation, and immunoprecipitation suggests that MUC1-N is located in nuclear speckles (interchromatin granule clusters) and closely associates with the spliceosome protein U2AF65. Nuclear localization of MUC1-N was abolished when cells were treated with RNase A and nuclear localization was altered when cells were incubated with the transcription inhibitor 5,6-dichloro-1-b-d-ribofuranosylbenzimidazole (DRB). While MUC1-N predominantly associated with speckles, MUC1-C was present in the nuclear matrix, nucleoli, and the nuclear periphery. In some nuclei, confocal microscopic analysis suggest that MUC1-C staining is located close to, but only partially overlaps, MUC1-N in speckles. However, only MUC1-N was found in isolated speckles by Western blotting. Also, MUC1-C and MUC1-N distributed differently during mitosis. These results suggest that MUC1-N translocates to the nucleus where it is expressed in nuclear speckles and that MUC1-N and MUC1-C have

  11. Expressions of integrin subunits in osteoblasts during weightlessness simulation using clionstat

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Wang, B.; Zhao, D.; Nie, J.; Li, Y.

    Space flight experiments and studies carried out in altered gravity environments have revealed that exposure to altered gravity conditions results in (mal)adaptation of cellular function. In the present study, we used a clinostat to generate a vector-averaged gravity to simulate weightlessness environment. We then observed the responses of rat calvarial osteoblasts subsequent to rotation at 30 revolutions per minute (rpm) for 72 h. We found that the gene expressions of three integrin subunits started to change from 24 h of rotation in clinostat but not in stationary cultures. The decreased percent changes of integrin a5 mRNA at 24, 48 and 72 h were 11.3 +/- 2.6%, 18.7 +/- 4.2% and 9.8 +/ - 2.1%, respectively. The same trend was saw in the expression of integrin av mRNA as 23.0 +/- 4.7%, 12.3 +/- 1.6% and 16.7 +/- 3.2%, respectively. Moreover, the expressions of integrin ß1 mRNA in different periods were also declined with the percent changes of 15.3 +/- 1.3%, 11.4 +/- 1.2% and 26.4 +/- 5.5%, respectively. All cells contain membrane-anchored attachment proteins able to recognize specific chemical motifs in the extracellular macromolecules forming the supporting scaffold, made of various types of collagen, adhesive glycoproteins, elastin, proteoglycans, etc. These cell-matrix interactions are mainly mediated by receptors of the integrins family, heterodimeric molecules made of an extracellular domain connected through a transmembrane sequence to an intracytoplasmic tail. Our results suggest that vector-averaged gravity causes alterations of signal transduction and integrin-mediated cell adhesion in osteoblasts by altering the gene expressions of several crucial integrin subunits. These alterations might contribute to the pathogenesis of osteoporotic bone loss as observed in actual space flights.

  12. Catalytic Subunit 1 of Protein Phosphatase 2A Is a Subunit of the STRIPAK Complex and Governs Fungal Sexual Development

    PubMed Central

    Beier, Anna; Krisp, Christoph; Wolters, Dirk A.

    2016-01-01

    ABSTRACT The generation of complex three-dimensional structures is a key developmental step for most eukaryotic organisms. The details of the molecular machinery controlling this step remain to be determined. An excellent model system to study this general process is the generation of three-dimensional fruiting bodies in filamentous fungi like Sordaria macrospora. Fruiting body development is controlled by subunits of the highly conserved striatin-interacting phosphatase and kinase (STRIPAK) complex, which has been described in organisms ranging from yeasts to humans. The highly conserved heterotrimeric protein phosphatase PP2A is a subunit of STRIPAK. Here, catalytic subunit 1 of PP2A was functionally characterized. The Δpp2Ac1 strain is sterile, unable to undergo hyphal fusion, and devoid of ascogonial septation. Further, PP2Ac1, together with STRIPAK subunit PRO22, governs vegetative and stress-related growth. We revealed in vitro catalytic activity of wild-type PP2Ac1, and our in vivo analysis showed that inactive PP2Ac1 blocks the complementation of the sterile deletion strain. Tandem affinity purification, followed by mass spectrometry and yeast two-hybrid analysis, verified that PP2Ac1 is a subunit of STRIPAK. Further, these data indicate links between the STRIPAK complex and other developmental signaling pathways, implying the presence of a large interconnected signaling network that controls eukaryotic developmental processes. The insights gained in our study can be transferred to higher eukaryotes and will be important for understanding eukaryotic cellular development in general. PMID:27329756

  13. Supported Molecular Matrix Electrophoresis.

    PubMed

    Matsuno, Yu-Ki; Kameyama, Akihiko

    2015-01-01

    Mucins are difficult to separate using conventional gel electrophoresis methods such as SDS-PAGE and agarose gel electrophoresis, owing to their large size and heterogeneity. On the other hand, cellulose acetate membrane electrophoresis can separate these molecules, but is not compatible with glycan analysis. Here, we describe a novel membrane electrophoresis technique, termed "supported molecular matrix electrophoresis" (SMME), in which a porous polyvinylidene difluoride (PVDF) membrane filter is used to achieve separation. This description includes the separation, visualization, and glycan analysis of mucins with the SMME technique.

  14. Downregulation of the δ-Subunit Reduces Mitochondrial ATP Synthase Levels, Alters Respiration, and Restricts Growth and Gametophyte Development in Arabidopsis[W][OA

    PubMed Central

    Geisler, Daniela A.; Päpke, Carola; Obata, Toshihiro; Nunes-Nesi, Adriano; Matthes, Annemarie; Schneitz, Kay; Maximova, Eugenia; Araújo, Wagner L.; Fernie, Alisdair R.; Persson, Staffan

    2012-01-01

    The mitochondrial ATP synthase (F1Fo complex) is an evolutionary conserved multimeric protein complex that synthesizes the main bulk of cytosolic ATP, but the regulatory mechanisms of the subunits are only poorly understood in plants. In yeast, the δ-subunit links the membrane-embedded Fo part to the matrix-facing central stalk of F1. We used genetic interference and an inhibitor to investigate the molecular function and physiological impact of the δ-subunit in Arabidopsis thaliana. Delta mutants displayed both male and female gametophyte defects. RNA interference of delta resulted in growth retardation, reduced ATP synthase amounts, and increased alternative oxidase capacity and led to specific long-term increases in Ala and Gly levels. By contrast, inhibition of the complex using oligomycin triggered broad metabolic changes, affecting glycolysis and the tricarboxylic acid cycle, and led to a successive induction of transcripts for alternative respiratory pathways and for redox and biotic stress-related transcription factors. We conclude that (1) the δ-subunit is essential for male gametophyte development in Arabidopsis, (2) a disturbance of the ATP synthase appears to lead to an early transition phase and a long-term metabolic steady state, and (3) the observed long-term adjustments in mitochondrial metabolism are linked to reduced growth and deficiencies in gametophyte development. PMID:22805435

  15. Compact moving least squares: An optimization framework for generating high-order compact meshless discretizations

    NASA Astrophysics Data System (ADS)

    Trask, Nathaniel; Maxey, Martin; Hu, Xiaozhe

    2016-12-01

    A generalization of the optimization framework typically used in moving least squares is presented that provides high-order approximation while maintaining compact stencils and a consistent treatment of boundaries. The approach, which we refer to as compact moving least squares, resembles the capabilities of compact finite differences but requires no structure in the underlying set of nodes. An efficient collocation scheme is used to demonstrate the capabilities of the method to solve elliptic boundary value problems in strong form stably without the need for an expensive weak form. The flexibility of the approach is demonstrated by using the same framework to both solve a variety of elliptic problems and to generate implicit approximations to derivatives. Finally, an efficient preconditioner is presented for the steady Stokes equations, and the approach's efficiency and high order of accuracy is demonstrated for domains with curvi-linear boundaries.

  16. Arrangement of Kv1 alpha subunits dictates sensitivity to tetraethylammonium.

    PubMed

    Al-Sabi, Ahmed; Shamotienko, Oleg; Dhochartaigh, Sorcha Ni; Muniyappa, Nagesh; Le Berre, Marie; Shaban, Hamdy; Wang, Jiafu; Sack, Jon T; Dolly, J Oliver

    2010-09-01

    Shaker-related Kv1 channels contain four channel-forming alpha subunits. Subfamily member Kv1.1 often occurs oligomerized with Kv1.2 alpha subunits in synaptic membranes, and so information was sought on the influence of their positions within tetramers on the channels' properties. Kv1.1 and 1.2 alpha genes were tandem linked in various arrangements, followed by expression as single-chain proteins in mammalian cells. As some concatenations reported previously seemed not to reliably position Kv1 subunits in their assemblies, the identity of expressed channels was methodically evaluated. Surface protein, isolated by biotinylation of intact transiently transfected HEK-293 cells, gave Kv1.1/1.2 reactivity on immunoblots with electrophoretic mobilities corresponding to full-length concatenated tetramers. There was no evidence of protein degradation, indicating that concatemers were delivered intact to the plasmalemma. Constructs with like genes adjacent (Kv1.1-1.1-1.2-1.2 or Kv1.2-1.2-1.1-1.1) yielded delayed-rectifying, voltage-dependent K(+) currents with activation parameters and inactivation kinetics slightly different from the diagonally positioned genes (Kv1.1-1.2-1.1-1.2 or 1.2-1.1-1.2-1.1). Pore-blocking petidergic toxins, alpha dendrotoxin, agitoxin-1, tityustoxin-Kalpha, and kaliotoxin, were unable to distinguish between the adjacent and diagonal concatamers. Unprecedentedly, external application of the pore-blocker tetraethylammonium (TEA) differentially inhibited the adjacent versus diagonal subunit arrangements, with diagonal constructs having enhanced susceptibility. Concatenation did not directly alter the sensitivities of homomeric Kv1.1 or 1.2 channels to TEA or the toxins. TEA inhibition of currents generated by channels made up from dimers (Kv1.1-1.2 and/or Kv1.2-1.1) was similar to the adjacently arranged constructs. These collective findings indicate that assembly of alpha subunits can be directed by this optimized concatenation, and that subunit

  17. Mechanism of β4 Subunit Modulation of BK Channels

    PubMed Central

    Wang, Bin; Rothberg, Brad S.; Brenner, Robert

    2006-01-01

    Large-conductance (BK-type) Ca2+-activated potassium channels are activated by membrane depolarization and cytoplasmic Ca2+. BK channels are expressed in a broad variety of cells and have a corresponding diversity in properties. Underlying much of the functional diversity is a family of four tissue-specific accessory subunits (β1–β4). Biophysical characterization has shown that the β4 subunit confers properties of the so-called “type II” BK channel isotypes seen in brain. These properties include slow gating kinetics and resistance to iberiotoxin and charybdotoxin blockade. In addition, the β4 subunit reduces the apparent voltage sensitivity of channel activation and has complex effects on apparent Ca2+ sensitivity. Specifically, channel activity at low Ca2+ is inhibited, while at high Ca2+, activity is enhanced. The goal of this study is to understand the mechanism underlying β4 subunit action in the context of a dual allosteric model for BK channel gating. We observed that β4's most profound effect is a decrease in Po (at least 11-fold) in the absence of calcium binding and voltage sensor activation. However, β4 promotes channel opening by increasing voltage dependence of Po-V relations at negative membrane potentials. In the context of the dual allosteric model for BK channels, we find these properties are explained by distinct and opposing actions of β4 on BK channels. β4 reduces channel opening by decreasing the intrinsic gating equilibrium (L0), and decreasing the allosteric coupling between calcium binding and voltage sensor activation (E). However, β4 has a compensatory effect on channel opening following depolarization by shifting open channel voltage sensor activation (Vho) to more negative membrane potentials. The consequence is that β4 causes a net positive shift of the G-V relationship (relative to α subunit alone) at low calcium. At higher calcium, the contribution by Vho and an increase in allosteric coupling to Ca2+ binding (C

  18. Lie-algebraic solutions of the type IIB matrix model

    NASA Astrophysics Data System (ADS)

    Chatzistavrakidis, Athanasios

    2011-11-01

    A systematic search for Lie-algebra solutions of the type IIB matrix model is performed. Our survey is based on the classification of all Lie algebras for dimensions up to five and of all nilpotent Lie algebras of dimension six. It is shown that Lie-type solutions of the equations of motion of the type IIB matrix model exist and they correspond to certain nilpotent and solvable Lie algebras. Their representation in terms of Hermitian matrices is discussed in detail. These algebras give rise to certain noncommutative spaces for which the corresponding star products are provided. Finally the issue of constructing quantized compact nilmanifolds and solvmanifolds based on the above algebras is addressed.

  19. Bedaquiline Targets the ε Subunit of Mycobacterial F-ATP Synthase.

    PubMed

    Kundu, Subhashri; Biukovic, Goran; Grüber, Gerhard; Dick, Thomas

    2016-11-01

    The tuberculosis drug bedaquiline inhibits mycobacterial F-ATP synthase by binding to its c subunit. Using the purified ε subunit of the synthase and spectroscopy, we previously demonstrated that the drug interacts with this protein near its unique tryptophan residue. Here, we show that replacement of ε's tryptophan with alanine resulted in bedaquiline hypersusceptibility of the bacteria. Overexpression of the wild-type ε subunit caused resistance. These results suggest that the drug also targets the ε subunit.

  20. Bedaquiline Targets the ε Subunit of Mycobacterial F-ATP Synthase

    PubMed Central

    Kundu, Subhashri; Biukovic, Goran; Grüber, Gerhard

    2016-01-01

    The tuberculosis drug bedaquiline inhibits mycobacterial F-ATP synthase by binding to its c subunit. Using the purified ε subunit of the synthase and spectroscopy, we previously demonstrated that the drug interacts with this protein near its unique tryptophan residue. Here, we show that replacement of ε's tryptophan with alanine resulted in bedaquiline hypersusceptibility of the bacteria. Overexpression of the wild-type ε subunit caused resistance. These results suggest that the drug also targets the ε subunit. PMID:27620476