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Sample records for affinity capture tandem

  1. Detection of protein-protein interactions using tandem affinity purification.

    Science.gov (United States)

    Goodfellow, Ian; Bailey, Dalan

    2014-01-01

    Tandem affinity purification (TAP) is an invaluable technique for identifying interaction partners for an affinity tagged bait protein. The approach relies on the fusion of dual tags to the bait before separate rounds of affinity purification and precipitation. Frequently two specific elution steps are also performed to increase the specificity of the overall technique. In the method detailed here, the two tags used are protein G and a short streptavidin binding peptide; however, many variations can be employed. In our example the tags are separated by a cleavable tobacco etch virus protease target sequence, allowing for specific elution after the first round of affinity purification. Proteins isolated after the final elution step in this process are concentrated before being identified by mass spectrometry. The use of dual affinity tags and specific elution in this technique dramatically increases both the specificity and stringency of the pull-downs, ensuring a low level of background nonspecific interactions.

  2. Identification of protein interacting partners using tandem affinity purification.

    Science.gov (United States)

    Bailey, Dalan; Urena, Luis; Thorne, Lucy; Goodfellow, Ian

    2012-02-25

    A critical and often limiting step in understanding the function of host and viral proteins is the identification of interacting cellular or viral protein partners. There are many approaches that allow the identification of interacting partners, including the yeast two hybrid system, as well as pull down assays using recombinant proteins and immunoprecipitation of endogenous proteins followed by mass spectrometry identification(1). Recent studies have highlighted the utility of double-affinity tag mediated purification, coupled with two specific elution steps in the identification of interacting proteins. This approach, termed Tandem Affinity Purification (TAP), was initially used in yeast(2,3) but more recently has been adapted to use in mammalian cells(4-8). As proof-of-concept we have established a tandem affinity purification (TAP) method using the well-characterized eukaryotic translation initiation factor eIF4E(9,10).The cellular translation factor eIF4E is a critical component of the cellular eIF4F complex involved in cap-dependent translation initiation(10). The TAP tag used in the current study is composed of two Protein G units and a streptavidin binding peptide separated by a Tobacco Etch Virus (TEV) protease cleavage sequence. The TAP tag used in the current study is composed of two Protein G units and a streptavidin binding peptide separated by a Tobacco Etch Virus (TEV) protease cleavage sequence(8). To forgo the need for the generation of clonal cell lines, we developed a rapid system that relies on the expression of the TAP-tagged bait protein from an episomally maintained plasmid based on pMEP4 (Invitrogen). Expression of tagged murine eIF4E from this plasmid was controlled using the cadmium chloride inducible metallothionein promoter. Lysis of the expressing cells and subsequent affinity purification via binding to rabbit IgG agarose, TEV protease cleavage, binding to streptavidin linked agarose and subsequent biotin elution identified numerous

  3. Identification of proteins associated with RNA polymerase III using a modified tandem chromatin affinity purification.

    Science.gov (United States)

    Nguyen, Ngoc-Thuy-Trinh; Saguez, Cyril; Conesa, Christine; Lefebvre, Olivier; Acker, Joël

    2015-02-01

    To identify the proteins associated with the RNA polymerase III (Pol III) machinery in exponentially growing yeast cells, we developed our own tandem chromatin affinity purification procedure (TChAP) after in vivo cross-link, allowing a reproducible and good recovery of the protein bait and its associated partners. In contrast to TFIIIA that could only be purified as a free protein, this protocol allows us to capture free Pol III together with Pol III bound on its target genes. Transcription factors, elongation factors, RNA-associated proteins and proteins involved in Pol III biogenesis were identified by mass spectrometry. Interestingly, the presence of all the TFIIIB subunits found associated with Pol III together with the absence of TFIIIC and chromatin factors including histones suggest that DNA-bound Pol III purified using TChAP is mainly engaged in transcription reinitiation.

  4. Tandem affinity purification of functional TAP-tagged proteins from human cells

    NARCIS (Netherlands)

    Gregan, Juraj; Riedel, Christian G; Petronczki, Mark; Cipak, Lubos; Rumpf, Cornelia; Poser, Ina; Buchholz, Frank; Mechtler, Karl; Nasmyth, Kim

    2007-01-01

    Tandem affinity purification (TAP) is a generic two-step affinity purification protocol for isolation of TAP-tagged proteins together with associated proteins. We used bacterial artificial chromosome to heterologously express TAP-tagged murine Sgo1 protein in human HeLa cells. This allowed us to tes

  5. Affine transformations capture beak shape variation in Darwin's Finches

    Science.gov (United States)

    Brenner, Michael; Campas, Otger; Mallarino, Riccardo; Abzhanov, Arhat

    2009-11-01

    Evolution by natural selection has resulted in extraordinary morphological complexity of living organisms, whose description has thus far defied any precise mathematical characterization linked to the underlying developmental genetics. Here we demonstrate that the morphological diversity of the beaks of Darwin's finches, the classical example of adaptive morphological radiation, is quantitatively accounted for through the mathematical group of affine transformations. Specifically, we show that all beak shapes of Ground Finches (genus Geospiza) are related by scaling transformations (a subgroup of the affine group), and the same scheme occurs for all the beak shapes of Tree and Warbler finches. This analysis shows that the beak shapes within each of these groups differ only by their scales, such as length and depth, each of which is knownto be under genetic control.The complete morphological variability within the beaks of Darwin's finches can be explained by extending the scaling transformations to the entire affine group, by including shear transformations. Altogether our results suggest that the mathematical theory of groups can help decode morphological variability, and points to a potentially hierarchical structure of morphological diversity and the underlying developmental processes.

  6. Twin-column CaptureSMB: a novel cyclic process for protein A affinity chromatography.

    Science.gov (United States)

    Angarita, Monica; Müller-Späth, Thomas; Baur, Daniel; Lievrouw, Roel; Lissens, Geert; Morbidelli, Massimo

    2015-04-10

    A twin-column counter-current chromatography processes, CaptureSMB, was used for the protein A affinity capture of a monoclonal antibody (mAb). By means of sequential loading, the process improves the utilization of the stationary phase by achieving loadings much closer to the static binding capacity of the resin in comparison to batch chromatography. Using a mAb capture case study with protein A affinity chromatography, the performance and product quality obtained from CaptureSMB and batch processes were compared. The effect of the flow rate, column length and titer concentration on the process performance and product quality were evaluated. CaptureSMB showed superior performance compared to batch chromatography with respect to productivity, capacity utilization, product concentration and buffer consumption. A simplified economic evaluation showed that CaptureSMB could decrease resin costs of 10-30% depending on the manufacturing scenario.

  7. Tandem affinity purification to identify cytosolic and nuclear gβγ-interacting proteins.

    Science.gov (United States)

    Campden, Rhiannon; Pétrin, Darlaine; Robitaille, Mélanie; Audet, Nicolas; Gora, Sarah; Angers, Stéphane; Hébert, Terence E

    2015-01-01

    It has become clear in recent years that the Gβγ subunits of heterotrimeric proteins serve broad roles in the regulation of cellular activity and interact with many proteins in different subcellular locations including the nucleus. Protein affinity purification is a common method to identify and confirm protein interactions. When used in conjugation with mass spectrometry it can be used to identify novel protein interactions with a given bait protein. The tandem affinity purification (TAP) technique identifies partner proteins bound to tagged protein bait. Combined with protocols to enrich the nuclear fraction of whole cell lysate through sucrose cushions, TAP allows for purification of interacting proteins found specifically in the nucleus. Here we describe the use of the TAP technique on cytosolic and nuclear lysates to identify candidate proteins, through mass spectrometry, that bind to Gβ1 subunits.

  8. Isolation of transcription factor complexes from Arabidopsis cell suspension cultures by tandem affinity purification.

    Science.gov (United States)

    Van Leene, Jelle; Eeckhout, Dominique; Persiau, Geert; Van De Slijke, Eveline; Geerinck, Jan; Van Isterdael, Gert; Witters, Erwin; De Jaeger, Geert

    2011-01-01

    Defining protein complexes is critical to virtually all aspects of cell biology because most cellular processes are regulated by stable or more dynamic protein interactions. Elucidation of the protein-protein interaction network around transcription factors is essential to fully understand their function and regulation. In the last decade, new technologies have emerged to study protein-protein interactions under near-physiological conditions. We have developed a high-throughput tandem affinity purification (TAP)/mass spectrometry (MS) platform for cell suspension cultures to analyze protein complexes in Arabidopsis thaliana. This streamlined platform follows an integrated approach comprising generic Gateway-based vectors with high cloning flexibility, the fast generation of transgenic suspension cultures, TAP adapted for plant cells, and tandem matrix-assisted laser desorption ionization MS for the identification of purified proteins. Recently, we evaluated the GS tag, originally developed to study mammalian protein complexes, that combines two IgG-binding domains of protein G with a streptavidin-binding peptide, separated by two tobacco etch virus cleavage sites. We found that this GS tag outperforms the traditional TAP tag in plant cells, regarding both specificity and complex yield. Here, we provide detailed protocols of the GS-based TAP platform that allowed us to characterize transcription factor complexes involved in signaling in response to the plant phytohormone jasmonate.

  9. Rapid purification of circular DNA by triplex-mediated affinity capture

    Science.gov (United States)

    Ji, H.; Smith, L.M.

    1997-01-07

    A single-step capture of a target supercoiled double-stranded DNA molecule is accomplished by forming a local triple-helix among two strands of the supercoiled circular DNA and an oligonucleotide probe. The oligonucleotide is bound to an immobilizing support which facilitates the immobilization and purification of target DNA molecules. Non-target DNA molecules and other contaminating cellular material are easily removed by washing. The triple-helical structure is destabilized by raising the pH, leaving purified target DNA in the supernatant and reusable affinity capture oligonucleotide secured to the immobilizing support. 3 figs.

  10. A tandem affinity purification tag of TGA2 for isolation of interacting proteins in Arabidopsis thaliana.

    Science.gov (United States)

    Stotz, Henrik U; Findling, Simone; Nukarinen, Ella; Weckwerth, Wolfram; Mueller, Martin J; Berger, Susanne

    2014-01-01

    Tandem affinity purification (TAP) tagging provides a powerful tool for isolating interacting proteins in vivo. TAP-tag purification offers particular advantages for the identification of stimulus-induced protein interactions. Type II bZIP transcription factors (TGA2, TGA5 and TGA6) play key roles in pathways that control salicylic acid, ethylene, xenobiotic and reactive oxylipin signaling. Although proteins interacting with these transcription factors have been identified through genetic and yeast 2-hybrid screening, others are still elusive. We have therefore generated a C-terminal TAP-tag of TGA2 to isolate additional proteins that interact with this transcription factor. Three lines most highly expressing TAP-tagged TGA2 were functional in that they partially complemented reactive oxylipin-responsive gene expression in a tga2 tga5 tga6 triple mutant. TAP-tagged TGA2 in the most strongly overexpressing line was proteolytically less stable than in the other 2 lines. Only this overexpressing line could be used in a 2-step purification process, resulting in isolation of co-purifying bands of larger molecular weight than TGA2. TAP-tagged TGA2 was used to pull down NPR1, a protein known to interact with this transcription factor. Mass spectrometry was used to identify peptides that co-purified with TAP-tagged TGA2. Having generated this TGA2 TAP-tag line will therefore be an asset to researchers interested in stimulus-induced signal transduction processes.

  11. A tandem affinity purification tag of TGA2 for isolation of interacting proteins in Arabidopsis thaliana.

    Science.gov (United States)

    Stotz, Henrik U; Findling, Simone; Nukarinen, Ella; Weckwerth, Wolfram; Mueller, Martin J; Berger, Susanne

    2014-08-19

    Tandem affinity purification (TAP) tagging provides a powerful tool for isolating interacting proteins in vivo. TAP-tag purification offers particular advantages for the identification of stimulus-induced protein interactions. Type II bZIP transcription factors (TGA2, TGA5 and TGA6) play key roles in pathways that control salicylic acid, ethylene, xenobiotic and reactive oxylipin signaling. Although proteins interacting with these transcription factors have been identified through genetic and yeast two-hybrid screening, others are still elusive. We have therefore generated a C-terminal TAP-tag of TGA2 to isolate additional proteins that interact with this transcription factor. Three lines most highly expressing TAP-tagged TGA2 were functional in that they partially complemented reactive oxylipin-responsive gene expression in a tga2 tga5 tga6 triple mutant. TAP-tagged TGA2 in the most strongly overexpressing line was proteolytically less stable than in the other two lines. Only this overexpressing line could be used in a two-step purification process, resulting in isolation of co-purifying bands of larger molecular weight than TGA2. TAP-tagged TGA2 was used to pull down NPR1, a protein known to interact with this transcription factor. Mass spectrometry was used to identify peptides that co-purified with TAP-tagged TGA2. Having generated this TGA2 TAP-tag line will therefore be an asset to researchers interested in stimulus-induced signal transduction processes.

  12. Radio frequency plasma polymer coatings for affinity capture MALDI mass spectrometry.

    Science.gov (United States)

    Li, Meiling; Timmons, Richard B; Kinsel, Gary R

    2005-01-01

    Surface modification of MALDI probes is an attractive approach for combining bioaffinity isolation of targeted biomolecules with mass spectrometric analysis of the captured species. In this work, we demonstrate that a polymer thin film, produced by pulsed rf plasma polymerization of allylamine and deposited directly on a MALDI probe, can be subsequently biotinylated to develop a bioaffinity capture MALDI probe. The synthesis and characterization of the probe by XPS, FT-IR, and AFM is described, and the selective isolation of avidin from a three-component mixture of avidin, lysozyme, and cytochrome c is presented. These initial results offer encouragement for the further exploration of rf plasma polymer deposition as a novel approach for the development of on-probe affinity capture MALDI probes.

  13. Density Gradient Ultracentrifugation to Isolate Endogenous Protein Complexes after Affinity Capture.

    Science.gov (United States)

    Fernandez-Martinez, Javier; LaCava, John; Rout, Michael P

    2016-07-01

    This protocol describes the isolation of native protein complexes by density gradient ultracentrifugation. The outcome of an affinity capture and native elution experiment is generally a mixture of (1) the complex(es) associated with the protein of interest under the specific conditions of capture, (2) fragments of the complex generated by degradation or disassembly during the purification procedure, and (3) the protease or reagent used to natively elute the sample. To separate these components and isolate a homogeneous complex, an additional step of purification is required. Rate-zonal density gradient ultracentrifugation is a reliable and powerful technique for separating particles based on their hydrodynamic volume. The density gradient is generated by mixing low- and high-density solutions of a suitable low-molecular-weight inert solute (e.g., sucrose or glycerol). The gradient is formed in a solvent that could be any of the solvents used for the affinity capture and native elution and should help to preserve the structure and activity of the assembly.

  14. Development of an epoxy-based monolith used for the affinity capturing of Escherichia coli bacteria.

    Science.gov (United States)

    Peskoller, Caroline; Niessner, Reinhard; Seidel, Michael

    2009-05-01

    An epoxy-based monolith has been developed for use as hydrophilic support in bioseparation. This monolith is produced by self-polymerization of polyglycerol-3-glycidyl ether in organic solvents as porogens at room temperature within 1 h. One receives a highly cross-linked structure that provides useful mechanical properties. The porosity and pore diameter can be controlled by varying the composition of the porogen. In this work, an epoxy-based monolith with a high porosity (79%) and large pore size (22 microm) is prepared and used in affinity capturing of bacterial cells. These features allow the passage of bacterial cells through the column. As affinity ligand polymyxin B is used, which allows the binding of gram-negative bacteria. The efficiency of the monolithic affinity column is studied with Escherichia coli spiked in water. Bacterial cells are concentrated on the column at pH 4 and eluted with a recovery of 97+/-3% in 200 microL by changing the pH value without impairing viability of bacteria. The dynamic capacity for the monolithic column is nearly independent of the flow rate (4x10(9)cells/column). Thereby, it is possible to separate and enrich gram-negative bacterial cells, such as E. coli, with high flow rates (10 mL/min) and low back pressure (<1 bar) in a volume as low as 200 microL compatible for real-time polymerase chain reaction, microarray formats, and biosensors.

  15. Discovery of protein complexes with core-attachment structures from Tandem Affinity Purification (TAP) data.

    Science.gov (United States)

    Wu, Min; Li, Xiao-Li; Kwoh, Chee-Keong; Ng, See-Kiong; Wong, Limsoon

    2012-09-01

    Many cellular functions involve protein complexes that are formed by multiple interacting proteins. Tandem Affinity Purification (TAP) is a popular experimental method for detecting such multi-protein interactions. However, current computational methods that predict protein complexes from TAP data require converting the co-complex relationships in TAP data into binary interactions. The resulting pairwise protein-protein interaction (PPI) network is then mined for densely connected regions that are identified as putative protein complexes. Converting the TAP data into PPI data not only introduces errors but also loses useful information about the underlying multi-protein relationships that can be exploited to detect the internal organization (i.e., core-attachment structures) of protein complexes. In this article, we propose a method called CACHET that detects protein complexes with Core-AttaCHment structures directly from bipartitETAP data. CACHET models the TAP data as a bipartite graph in which the two vertex sets are the baits and the preys, respectively. The edges between the two vertex sets represent bait-prey relationships. CACHET first focuses on detecting high-quality protein-complex cores from the bipartite graph. To minimize the effects of false positive interactions, the bait-prey relationships are indexed with reliability scores. Only non-redundant, reliable bicliques computed from the TAP bipartite graph are regarded as protein-complex cores. CACHET constructs protein complexes by including attachment proteins into the cores. We applied CACHET on large-scale TAP datasets and found that CACHET outperformed existing methods in terms of prediction accuracy (i.e., F-measure and functional homogeneity of predicted complexes). In addition, the protein complexes predicted by CACHET are equipped with core-attachment structures that provide useful biological insights into the inherent functional organization of protein complexes. Our supplementary material can

  16. Application of a novel affinity adsorbent for the capture and purification of recombinant factor VIII compounds.

    Science.gov (United States)

    McCue, Justin T; Selvitelli, Keith; Walker, Joshua

    2009-11-06

    Recombinant Factor VIII (FVIII) therapies have been created to provide treatment for Hemophilia A, an inherited bleeding disorder caused by mutation in the FVIII gene. A major challenge in the purification of recombinant FVIII molecules is the development of an affinity chromatography step. Such a step must be highly specific and selective for the FVIII molecule, but also must be designed appropriately to ensure the FVIII molecule can be effectively recovered without resorting to harsh elution conditions which may be harmful to the product. Additionally, it is desirable to have affinity adsorbents designed to be reusable over a large number of column cycles while maintaining consistent purification performance. In this work, we describe the use of VIIISelect, a commercially available affinity adsorbent designed specifically for the purification of FVIII compounds. The VIIISelect adsorbent consists of a 13kDa recombinant protein ligand attached to a cross-linked agarose base matrix. The structure of the recombinant ligand is based upon Camelid-derived single domain antibody fragments. The VIIISelect adsorbent is produced using a process free of animal-derived raw materials, which is a highly desirable attribute for adsorbents used in the purification processes of recombinant protein therapeutics. The VIIISelect adsorbent was used as the initial capture column to purify a FVIII compound directly from clarified cell culture fluid prior to further downstream purification. The purification performance of the VIIISelect was evaluated, which included measurement of the static binding capacity, dynamic binding capacity, product recovery, impurity clearance, and adsorbent reuse. Following laboratory-scale process development, the VIIISelect adsorbent was scaled up and used in the large scale manufacturing of a FVIII compound.

  17. An improved toolbox to unravel the plant cellular machinery by tandem affinity purification of Arabidopsis protein complexes.

    Science.gov (United States)

    Van Leene, Jelle; Eeckhout, Dominique; Cannoot, Bernard; De Winne, Nancy; Persiau, Geert; Van De Slijke, Eveline; Vercruysse, Leen; Dedecker, Maarten; Verkest, Aurine; Vandepoele, Klaas; Martens, Lennart; Witters, Erwin; Gevaert, Kris; De Jaeger, Geert

    2015-01-01

    Tandem affinity purification coupled to mass spectrometry (TAP-MS) is one of the most advanced methods to characterize protein complexes in plants, giving a comprehensive view on the protein-protein interactions (PPIs) of a certain protein of interest (bait). The bait protein is fused to a double affinity tag, which consists of a protein G tag and a streptavidin-binding peptide separated by a very specific protease cleavage site, allowing highly specific protein complex isolation under near-physiological conditions. Implementation of this optimized TAP tag, combined with ultrasensitive MS, means that these experiments can be performed on small amounts (25 mg of total protein) of protein extracts from Arabidopsis cell suspension cultures. It is also possible to use this approach to isolate low abundant protein complexes from Arabidopsis seedlings, thus opening perspectives for the exploration of protein complexes in a plant developmental context. Next to protocols for efficient biomass generation of seedlings (∼7.5 months), we provide detailed protocols for TAP (1 d), and for sample preparation and liquid chromatography-tandem MS (LC-MS/MS; ∼5 d), either from Arabidopsis seedlings or from cell cultures. For the identification of specific co-purifying proteins, we use an extended protein database and filter against a list of nonspecific proteins on the basis of the occurrence of a co-purified protein among 543 TAP experiments. The value of the provided protocols is illustrated through numerous applications described in recent literature.

  18. TANDEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Tandem Van de Graaff facility provides researchers with beams of more than 40 different types of ions - atoms that have been stripped of their electrons. One of...

  19. A study of resonance electron capture ionization on a quadrupole tandem mass spectrometer.

    Science.gov (United States)

    Wei, J; Liu, S; Fedoreyev, S A; Voinov, V G

    2000-01-01

    Procedures that allow the realization of resonance electron capture (REC) mode on a commercial triple-quadrupole mass spectrometer, after some simple modifications, are described. REC mass spectrometry (MS) and tandem mass spectrometry (MS/MS) experiments were performed and spectra for some compounds were recorded. In particular, the charge-remote fragmentation (CRF) spectra of [M - H](-) ions of docosanoic and docosenoic acids under low-energy collisionally activated dissociation (CAD) conditions were obtained, and showed that there were no significant differences for [M - H](-) ions produced at different resonances (i.e. for [M - H](-) ions with different structures). This observation was explained on the basis of results obtained from deuterium-labeled fatty acids, which showed that different CRF ions (but with the same m/z value in the absence of labels) could be produced by different mechanisms, and all of them were obviously realized under CAD conditions that made spectra practically indistinguishable. The other example, which compared the REC-MS/MS spectrum of [M - H](-) ions and EI-MS/MS spectrum of M(+.) ions of daidzein, demonstrated the potential of the REC-MS/MS technique for more complex structure elucidation.

  20. Isolation of ubiquitinated substrates by tandem affinity purification of E3 ligase-polyubiquitin-binding domain fusions (ligase traps).

    Science.gov (United States)

    Mark, Kevin G; Loveless, Theresa B; Toczyski, David P

    2016-02-01

    Ubiquitination is an essential protein modification that influences eukaryotic processes ranging from substrate degradation to nonproteolytic pathway alterations, including DNA repair and endocytosis. Previous attempts to analyze substrates via physical association with their respective ubiquitin ligases have had some success. However, because of the transient nature of enzyme-substrate interactions and rapid protein degradation, detection of substrates remains a challenge. Ligase trapping is an affinity purification approach in which ubiquitin ligases are fused to a polyubiquitin-binding domain, which allows the isolation of ubiquitinated substrates. Immunoprecipitation is first used to enrich for proteins that are bound to the ligase trap. Subsequently, affinity purification is used under denaturing conditions to capture proteins conjugated with hexahistidine-tagged ubiquitin. By using this protocol, ubiquitinated substrates that are specific for a given ligase can be isolated for mass spectrometry or western blot analysis. After cells have been collected, the described protocol can be completed in 2-3 d.

  1. Data on the identification of protein interactors with the Evening Complex and PCH1 in Arabidopsis using tandem affinity purification and mass spectrometry (TAP-MS).

    Science.gov (United States)

    Huang, He; Alvarez, Sophie; Nusinow, Dmitri A

    2016-09-01

    Tandem affinity purification coupled with mass spectrometry (TAP-MS) analysis is a powerful biochemical approach to identify protein-protein associations. Here we describe two datasets generated by a series of TAP-MS analyses to co-purify proteins associated with either ELF3 or ELF4 of the Evening Complex (EC) ("Identification of Evening Complex Associated Proteins in Arabidopsis by Affinity Purification and Mass Spectrometry" (Huang et al., 2016a) [1]) or proteins associated with PCH1, which is a newly identified output of the circadian clock to regulate photoperiodic growth in Arabidopsis thaliana ("PCH1 integrates circadian and light-signaling pathways to control photoperiod-responsive growth in Arabidopsis" (Huang et al. 2016b) [2]). We used either ELF3, ELF4 or PCH1 fused to a C-terminal tandem affinity tag (6xHis-3xFLAG) as baits and conducted purifications in various genetic mutant backgrounds. These data are discussed in recent publications [1,2], and are deposited at the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PRIDE: PXD002606 (for EC) and PRIDE: PXD003352 (for PCH1).

  2. Development of a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kreiner, A.J., E-mail: kreiner@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina)] [CONICET, Buenos Aires (Argentina); Castell, W. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Di Paolo, H. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Baldo, M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [CONICET, Buenos Aires (Argentina)

    2011-12-15

    We describe the present status of an ongoing project to develop a Tandem-ElectroStatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based (AB)-BNCT. The project final goal is a machine capable of delivering 30 mA of 2.4 MeV protons to be used in conjunction with a neutron production target based on the {sup 7}Li(p,n){sup 7}Be reaction. The machine currently being constructed is a folded TESQ with a high-voltage terminal at 0.6 MV. We report here on the progress achieved in a number of different areas.

  3. Laser capture microdissection and multiplex-tandem PCR analysis of proximal tubular epithelial cell signaling in human kidney disease.

    Directory of Open Access Journals (Sweden)

    Ray Wilkinson

    Full Text Available Interstitial fibrosis, a histological process common to many kidney diseases, is the precursor state to end stage kidney disease, a devastating and costly outcome for the patient and the health system. Fibrosis is historically associated with chronic kidney disease (CKD but emerging evidence is now linking many forms of acute kidney disease (AKD with the development of CKD. Indeed, we and others have observed at least some degree of fibrosis in up to 50% of clinically defined cases of AKD. Epithelial cells of the proximal tubule (PTEC are central in the development of kidney interstitial fibrosis. We combine the novel techniques of laser capture microdissection and multiplex-tandem PCR to identify and quantitate "real time" gene transcription profiles of purified PTEC isolated from human kidney biopsies that describe signaling pathways associated with this pathological fibrotic process. Our results: (i confirm previous in-vitro and animal model studies; kidney injury molecule-1 is up-regulated in patients with acute tubular injury, inflammation, neutrophil infiltration and a range of chronic disease diagnoses, (ii provide data to inform treatment; complement component 3 expression correlates with inflammation and acute tubular injury, (iii identify potential new biomarkers; proline 4-hydroxylase transcription is down-regulated and vimentin is up-regulated across kidney diseases, (iv describe previously unrecognized feedback mechanisms within PTEC; Smad-3 is down-regulated in many kidney diseases suggesting a possible negative feedback loop for TGF-β in the disease state, whilst tight junction protein-1 is up-regulated in many kidney diseases, suggesting feedback interactions with vimentin expression. These data demonstrate that the combined techniques of laser capture microdissection and multiplex-tandem PCR have the power to study molecular signaling within single cell populations derived from clinically sourced tissue.

  4. Laser capture microdissection and multiplex-tandem PCR analysis of proximal tubular epithelial cell signaling in human kidney disease.

    Science.gov (United States)

    Wilkinson, Ray; Wang, Xiangju; Kassianos, Andrew J; Zuryn, Steven; Roper, Kathrein E; Osborne, Andrew; Sampangi, Sandeep; Francis, Leo; Raghunath, Vishwas; Healy, Helen

    2014-01-01

    Interstitial fibrosis, a histological process common to many kidney diseases, is the precursor state to end stage kidney disease, a devastating and costly outcome for the patient and the health system. Fibrosis is historically associated with chronic kidney disease (CKD) but emerging evidence is now linking many forms of acute kidney disease (AKD) with the development of CKD. Indeed, we and others have observed at least some degree of fibrosis in up to 50% of clinically defined cases of AKD. Epithelial cells of the proximal tubule (PTEC) are central in the development of kidney interstitial fibrosis. We combine the novel techniques of laser capture microdissection and multiplex-tandem PCR to identify and quantitate "real time" gene transcription profiles of purified PTEC isolated from human kidney biopsies that describe signaling pathways associated with this pathological fibrotic process. Our results: (i) confirm previous in-vitro and animal model studies; kidney injury molecule-1 is up-regulated in patients with acute tubular injury, inflammation, neutrophil infiltration and a range of chronic disease diagnoses, (ii) provide data to inform treatment; complement component 3 expression correlates with inflammation and acute tubular injury, (iii) identify potential new biomarkers; proline 4-hydroxylase transcription is down-regulated and vimentin is up-regulated across kidney diseases, (iv) describe previously unrecognized feedback mechanisms within PTEC; Smad-3 is down-regulated in many kidney diseases suggesting a possible negative feedback loop for TGF-β in the disease state, whilst tight junction protein-1 is up-regulated in many kidney diseases, suggesting feedback interactions with vimentin expression. These data demonstrate that the combined techniques of laser capture microdissection and multiplex-tandem PCR have the power to study molecular signaling within single cell populations derived from clinically sourced tissue.

  5. Tandem Affinity Purification Approach Coupled to Mass Spectrometry to Identify Post-translational Modifications of Histones Associated with Chromatin-Binding Proteins.

    Science.gov (United States)

    Beyer, Sophie; Robin, Philippe; Ait-Si-Ali, Slimane

    2017-01-01

    Protein purification by tandem affinity purification (TAP)-tag coupled to mass spectrometry analysis is usually used to reveal protein complex composition. Here we describe a TAP-tag purification of chromatin-bound proteins along with associated nucleosomes, which allow exhaustive identification of protein partners. Moreover, this method allows exhaustive identification of the post-translational modifications (PTMs) of the associated histones. Thus, in addition to partner characterization, this approach reveals the associated epigenetic landscape that can shed light on the function and properties of the studied chromatin-bound protein.

  6. Advance chromatin extraction improves capture performance of protein A affinity chromatography.

    Science.gov (United States)

    Nian, Rui; Zhang, Wei; Tan, Lihan; Lee, Jeremy; Bi, Xeuzhi; Yang, Yuansheng; Gan, Hui Theng; Gagnon, Pete

    2016-01-29

    Practical effects of advance chromatin removal on performance of protein A affinity chromatography were evaluated using a caprylic acid-allantoin-based extraction method. Lacking this treatment, the practice of increasing loading residence time to increase capacity was shown to increase host protein contamination of the eluted IgG. Advance chromatin extraction suspended that compromise. Protein A ligand leakage from columns loaded with chromatin-extracted harvest was half the level observed on protein A columns loaded with non-extracted harvest. Columns loaded with chromatin-extracted harvest were cleaned more effectively by 50-100mM NaOH than columns loaded with non-extracted harvest that were cleaned with 250-500mM NaOH. Two protein A media with IgG capacities in excess of 50g/L were loaded with chromatin-extracted harvest, washed with 2.0M NaCl before elution, and the eluted IgG fraction titrated to pH 5.5 before microfiltration. Host protein contamination in the filtrate was reduced to protein A leakage to 0.5ppm, and aggregates to 1.0%. Caprylic acid and allantoin were both reduced below 5ppm. Step recovery of IgG was 99.4%. Addition of a single polishing step reduced residual protein A beneath the level of detection and aggregates to <0.1%. Overall process recovery including chromatin extraction was 90%.

  7. Generation of monospecific antibodies based on affinity capture of polyclonal antibodies.

    Science.gov (United States)

    Hjelm, Barbara; Forsström, Björn; Igel, Ulrika; Johannesson, Henrik; Stadler, Charlotte; Lundberg, Emma; Ponten, Fredrik; Sjöberg, Anna; Rockberg, Johan; Schwenk, Jochen M; Nilsson, Peter; Johansson, Christine; Uhlén, Mathias

    2011-11-01

    A method is described to generate and validate antibodies based on mapping the linear epitopes of a polyclonal antibody followed by sequential epitope-specific capture using synthetic peptides. Polyclonal antibodies directed towards four proteins RBM3, SATB2, ANLN, and CNDP1, potentially involved in human cancers, were selected and antibodies to several non-overlapping epitopes were generated and subsequently validated by Western blot, immunohistochemistry, and immunofluorescence. For all four proteins, a dramatic difference in functionality could be observed for these monospecific antibodies directed to the different epitopes. In each case, at least one antibody was obtained with full functionality across all applications, while other epitope-specific fractions showed no or little functionality. These results present a path forward to use the mapped binding sites of polyclonal antibodies to generate epitope-specific antibodies, providing an attractive approach for large-scale efforts to characterize the human proteome by antibodies.

  8. Affinity capture using peptide-functionalized magnetic nanoparticles to target Staphylococcus aureus

    Science.gov (United States)

    Kuo, Fang-Yin; Lin, Wei-Lien; Chen, Yu-Chie

    2016-04-01

    Staphylococcus aureus, a commonly found pathogen, can cause food poisoning and infections. Thus, it is necessary to develop analytical methods for the rapid screening of S. aureus in suspicious samples. Magnetic nanoparticles (MNPs) are widely used as affinity probes to selectively enrich target species from complex samples because of their high specific surface area and magnetic properties. The MNP surface should be functionalized to have the capability to target specific species. We herein propose a straightforward method to functionalize aluminum oxide-coated iron oxide (Fe3O4@Al2O3) MNPs with the peptide HHHHHHDEEGLFVD (D). The peptide D was comprised of three domains: polyhistidine (H6) used as the linker, DEE added as the spacer, and GLFVD used for targeting S. aureus. D was immobilized on the surface of Fe3O4@Al2O3 MNPs through H6-Al chelation. Our results showed that the D-functionalized Fe3O4@Al2O3 MNPs (D-Fe3O4 MNPs) possess the capability to target S. aureus. The selective trapping experiments were conducted under microwave-heating for only 60 s, and sufficient bacterial cells were trapped by the MNPs to be identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). We demonstrated that the D-Fe3O4@Al2O3 MNPs combined with MALDI-MS can be used to rapidly characterize trace amounts of S. aureus in complex juice and egg samples.Staphylococcus aureus, a commonly found pathogen, can cause food poisoning and infections. Thus, it is necessary to develop analytical methods for the rapid screening of S. aureus in suspicious samples. Magnetic nanoparticles (MNPs) are widely used as affinity probes to selectively enrich target species from complex samples because of their high specific surface area and magnetic properties. The MNP surface should be functionalized to have the capability to target specific species. We herein propose a straightforward method to functionalize aluminum oxide-coated iron oxide (Fe3O4@Al2O3) MNPs with the

  9. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thatar Vento, V., E-mail: Vladimir.ThatarVento@gmail.com [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina); Bergueiro, J.; Cartelli, D. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina); Valda, A.A. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, UNSAM, M. Irigoyen 3100 (1650), San Martin, Buenos Aires (Argentina); Kreiner, A.J. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, UNSAM, M. Irigoyen 3100 (1650), San Martin, Buenos Aires (Argentina)

    2011-12-15

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam.

  10. Tandem affinity purification of histones, coupled to mass spectrometry, identifies associated proteins and new sites of post-translational modification in Saccharomyces cerevisiae.

    Science.gov (United States)

    Valero, M Luz; Sendra, Ramon; Pamblanco, Mercè

    2016-03-16

    Histones and their post-translational modifications contribute to regulating fundamental biological processes in all eukaryotic cells. We have applied a conventional tandem affinity purification strategy to histones H3 and H4 of the yeast Saccharomyces cerevisiae. Mass spectrometry analysis of the co-purified proteins revealed multiple associated proteins, including core histones, which indicates that tagged histones may be incorporated to the nucleosome particle. Among the many other co-isolated proteins there are histone chaperones, elements of chromatin remodeling, of nucleosome assembly/disassembly, and of histone modification complexes. The histone chaperone Rtt106p, two members of chromatin assembly FACT complex and Psh1p, an ubiquitin ligase, were the most abundant proteins obtained with both H3-TAP and H4-TAP, regardless of the cell extraction medium stringency. Our mass spectrometry analyses have also revealed numerous novel post-translational modifications, including 30 new chemical modifications in histones, mainly by ubiquitination. We have discovered not only new sites of ubiquitination but that, besides lysine, also serine and threonine residues are targets of ubiquitination on yeast histones. Our results show the standard tandem affinity purification procedure is suitable for application to yeast histones, in order to isolate and characterize histone-binding proteins and post-translational modifications, avoiding the bias caused by histone purification from a chromatin-enriched fraction.

  11. Proteome-wide identification of novel binding partners to the oncogenic fusion gene protein, NPM-ALK, using tandem affinity purification and mass spectrometry.

    Science.gov (United States)

    Wu, Fang; Wang, Peng; Young, Leah C; Lai, Raymond; Li, Liang

    2009-02-01

    Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), an oncogenic fusion gene protein that is characteristically found in a subset of anaplastic large cell lymphomas, promotes tumorigenesis through its functional and physical interactions with various biologically important proteins. The identification of these interacting proteins has proven to be useful to further our understanding of NPM-ALK-mediated tumorigenesis. For the first time, we performed a proteome-wide identification of NPM-ALK-binding proteins using tandem affinity purification and a highly sensitive mass spectrometric technique. Tandem affinity purification is a recently developed method that carries a lower background and higher sensitivity compared with the conventional immunoprecipitation-based protein purification protocols. The NPM-ALK gene was cloned into an HB-tagged vector and expressed in GP293 cells. Three independent experiments were performed and the reproducibility of the data was 68%. The vast majority of the previously reported NPM-ALK-binding proteins were detected. We also identified proteins that are involved in various cellular processes that were not previously described in association with NPM-ALK, such as MCM6 and MSH2 (DNA repair), Nup98 and importin 8 (subcellular protein transport), Stim1 (calcium signaling), 82Fip (RNA regulation), and BAG2 (proteosome degradation). We believe that these data highlight the functional diversity of NPM-ALK and provide new research directions for the study of the biology of this oncoprotein.

  12. Profiling of drug binding proteins by monolithic affinity chromatography in combination with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Xuepei; Wang, Tongdan; Zhang, Hanzhi; Han, Bing; Wang, Lishun; Kang, Jingwu

    2014-09-12

    A new approach for proteome-wide profiling drug binding proteins by using monolithic capillary affinity chromatography in combination with HPLC-MS/MS is reported. Two immunosuppresive drugs, namely FK506 and cyclosporin A, were utilized as the experimental models for proof-of-concept. The monolithic capillary affinity columns were prepared through a single-step copolymerization of the drug derivatives with glycidyl methacrylate and ethylene dimethacrylate. The capillary chromatography with the affinity monolithic column facilitates the purification of the drug binding proteins from the cell lysate. By combining the capillary affinity column purification and the shot-gun proteomic analysis, totally 33 FK506- and 32 CsA-binding proteins including all the literature reported target proteins of these two drugs were identified. Among them, two proteins, namely voltage-dependent anion-selective channel protein 1 and serine/threonine-protein phosphatase PGAM5 were verified by using the recombinant proteins. The result supports that the monolithic capillary affinity chromatography is likely to become a valuable tool for profiling of binding proteins of small molecular drugs as well as bioactive compounds.

  13. A review of electron-capture and electron-transfer dissociation tandem mass spectrometry in polymer chemistry.

    Science.gov (United States)

    Hart-Smith, Gene

    2014-01-15

    Mass spectrometry (MS)-based studies of synthetic polymers often characterise detected polymer components using mass data alone. However when mass-based characterisations are ambiguous, tandem MS (MS/MS) offers a means by which additional analytical information may be collected. This review provides a synopsis of two particularly promising methods of dissociating polymer ions during MS/MS: electron-capture and electron-transfer dissociation (ECD and ETD, respectively). The article opens with a summary of the basic characteristics and operating principles of ECD and ETD, and relates these techniques to other methods of dissociating gas-phase ions, such as collision-induced dissociation (CID). Insights into ECD- and ETD-based MS/MS, gained from studies into proteins and peptides, are then discussed in relation to polymer chemistry. Finally, ECD- and ETD-based studies into various classes of polymer are summarised; for each polymer class, ECD- and ETD-derived data are compared to CID-derived data. These discussions identify ECD and ETD as powerful means by which unique and diagnostically useful polymer ion fragmentation data may be generated, and techniques worthy of increased utilisation by the polymer chemistry community.

  14. Chromatography on DEAE ion-exchange and Protein G affinity columns in tandem for the separation and purification of proteins.

    Science.gov (United States)

    Qi, Y; Yan, Z; Huang, J

    2001-10-30

    A high-performance liquid-chromatographic method based on coupled DEAE anion-exchange and Protein G affinity columns has been developed for the simultaneous separation and purification of immunoglobulin G and albumin from mouse serum. The diluted mouse serum was injected directly into this system, and the proteins were eluted separately from the DEAE and Protein G columns, coupled in series, by the column-switching technique. The advantages of this method are that IgG and albumin can be separated and purified simultaneously, the expensive affinity column is protected from contamination by the impurities in the mouse serum, and it is fast, selective, robust, and reproducible.

  15. Use of a tandem affinity purification assay to detect interactions between West Nile and dengue viral proteins and proteins of the mosquito vector.

    Science.gov (United States)

    Colpitts, Tonya M; Cox, Jonathan; Nguyen, Annie; Feitosa, Fabiana; Krishnan, Manoj N; Fikrig, Erol

    2011-08-15

    West Nile and dengue viruses are (re)emerging mosquito-borne flaviviruses that cause significant morbidity and mortality in man. The identification of mosquito proteins that associate with flaviviruses may provide novel targets to inhibit infection of the vector or block transmission to humans. Here, a tandem affinity purification (TAP) assay was used to identify 18 mosquito proteins that interact with dengue and West Nile capsid, envelope, NS2A or NS2B proteins. We further analyzed the interaction of mosquito cadherin with dengue and West Nile virus envelope protein using co-immunoprecipitation and immunofluorescence. Blocking the function of select mosquito factors, including actin, myosin, PI3-kinase and myosin light chain kinase, reduced both dengue and West Nile virus infection in mosquito cells. We show that the TAP method may be used in insect cells to accurately identify flaviviral-host protein interactions. Our data also provides several targets for interrupting flavivirus infection in mosquito vectors.

  16. Tandem mass spectrometry of human tryptic blood peptides calculated by a statistical algorithm and captured by a relational database with exploration by a general statistical analysis system.

    Science.gov (United States)

    Bowden, Peter; Beavis, Ron; Marshall, John

    2009-11-02

    A goodness of fit test may be used to assign tandem mass spectra of peptides to amino acid sequences and to directly calculate the expected probability of mis-identification. The product of the peptide expectation values directly yields the probability that the parent protein has been mis-identified. A relational database could capture the mass spectral data, the best fit results, and permit subsequent calculations by a general statistical analysis system. The many files of the Hupo blood protein data correlated by X!TANDEM against the proteins of ENSEMBL were collected into a relational database. A redundant set of 247,077 proteins and peptides were correlated by X!TANDEM, and that was collapsed to a set of 34,956 peptides from 13,379 distinct proteins. About 6875 distinct proteins were only represented by a single distinct peptide, 2866 proteins showed 2 distinct peptides, and 3454 proteins showed at least three distinct peptides by X!TANDEM. More than 99% of the peptides were associated with proteins that had cumulative expectation values, i.e. probability of false positive identification, of one in one hundred or less. The distribution of peptides per protein from X!TANDEM was significantly different than those expected from random assignment of peptides.

  17. Affinity labeling coupled with matrix assistant laser desorption tandem time of flight mass spectrometry for quantitative proteomies research

    Institute of Scientific and Technical Information of China (English)

    MENG Qingfang; ZHANG Yangjun; CAI Yun; QIAN Xiaohong

    2007-01-01

    A relative quantitative method for differential proteomics by cleavable isotope-coded atTmity tag (cICAT)and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-MS) was estab-lished. The accuracy and reproducibility of the method were evaluated by bovine serum albumin (BSA) digest as having a relative standard deviation of less than 30% and good reproducibility. The dynamic range was als0 evaluated by analyzing two mixtures of several standard proteins with dif-ferent concentration. The experimental results showed that in the dynamic range of 1:30, the quantitation error of the method was less than 30%. Although the quantitation error becomes very large when used beyond this range, it does not affect the derivation of information on the differential proteins. All the work provides an alternative method for differential proteomics analysis in biological samples from different origins.

  18. The Aryl-Hydrocarbon Receptor Protein Interaction Network (AHR-PIN as Identified by Tandem Affinity Purification (TAP and Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Dorothy M. Tappenden

    2013-01-01

    Full Text Available The aryl-hydrocarbon receptor (AHR, a ligand activated PAS superfamily transcription factor, mediates most, if not all, of the toxicity induced upon exposure to various dioxins, dibenzofurans, and planar polyhalogenated biphenyls. While AHR-mediated gene regulation plays a central role in the toxic response to dioxin exposure, a comprehensive understanding of AHR biology remains elusive. AHR-mediated signaling starts in the cytoplasm, where the receptor can be found in a complex with the heat shock protein of 90 kDa (Hsp90 and the immunophilin-like protein, aryl-hydrocarbon receptor-interacting protein (AIP. The role these chaperones and other putative interactors of the AHR play in the toxic response is not known. To more comprehensively define the AHR-protein interaction network (AHR-PIN and identify other potential pathways involved in the toxic response, a proteomic approach was undertaken. Using tandem affinity purification (TAP and mass spectrometry we have identified several novel protein interactions with the AHR. These interactions physically link the AHR to proteins involved in the immune and cellular stress responses, gene regulation not mediated directly via the traditional AHR:ARNT heterodimer, and mitochondrial function. This new insight into the AHR signaling network identifies possible secondary signaling pathways involved in xenobiotic-induced toxicity.

  19. Functional characterization of the kinase activation loop in nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) using tandem affinity purification and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Wang, Peng; Wu, Fang; Ma, Yupo; Li, Liang; Lai, Raymond; Young, Leah C

    2010-01-01

    Previous studies have shown that the kinase activation loop (KAL) of the oncogenic fusion protein NPM-ALK regulates its overall tyrosine phosphorylation status and tumorigenicity. Using tandem affinity purification-mass spectrometry, we assessed how the KAL of NPM-ALK regulates the phosphorylation status of its individual tyrosines. Using the lysates of GP293 cells transfected with NPM-ALK, our highly reproducible results showed evidence of phosphorylation in all 3 tyrosines in KAL and 8 tyrosines outside KAL. We created 7 KAL mutants, each of which carried a Tyr-to-Phe mutation of >or=1 of the 3 tyrosines in KAL. A complete loss of the 8 phosphotyrosines outside KAL was found in 3 KAL mutants, and their oncogenicity (assessed by cell viability, colony formation, and the ability to phosphorylate effector proteins) was abrogated. A partial loss of the 8 phosphotyrosines was found in 4 KAL mutants, but their oncogenicity did not show simple correlation with the number of residual phosphotyrosines. Tyr-to-Phe mutations of each of the 8 phosphotyrosines outside KAL did not result in a significant decrease in the oncogenicity. In conclusion, we have provided details of how the KAL in NPM-ALK regulates its tyrosine phosphorylation pattern. Our results challenge some of the current concepts regarding the relationship between the tyrosine phosphorylation and oncogenicity of NPM-ALK.

  20. Development of high intensity ion sources for a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Igarzabal, M.; Suarez Sandin, J.C. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina); Somacal, H.R. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Thatar Vento, V. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Huck, H.; Valda, A.A. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Repetto, M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)

    2011-12-15

    Several ion sources have been developed and an ion source test stand has been mounted for the first stage of a Tandem-Electrostatic-Quadrupole facility For Accelerator-Based Boron Neutron Capture Therapy. A first source, designed, fabricated and tested is a dual chamber, filament driven and magnetically compressed volume plasma proton ion source. A 4 mA beam has been accelerated and transported into the suppressed Faraday cup. Extensive simulations of the sources have been performed using both 2D and 3D self-consistent codes.

  1. Monodisperse REPO4 (RE = Yb, Gd, Y) hollow microspheres covered with nanothorns as affinity probes for selectively capturing and labeling phosphopeptides.

    Science.gov (United States)

    Cheng, Gong; Zhang, Ji-Lin; Liu, Yan-Lin; Sun, De-Hui; Ni, Jia-Zuan

    2012-02-13

    Rare-earth phosphate microspheres with unique structures were developed as affinity probes for the selective capture and tagging of phosphopeptides. Prickly REPO(4) (RE = Yb, Gd, Y) monodisperse microspheres, that have hollow structures, low densities, high specific surface areas, and large adsorptive capacities were prepared by an ion-exchange method. The elemental compositions and crystal structures of these affinity probes were confirmed by energy-dispersive spectroscopy (EDS), powder X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The morphologies of these compounds were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen-adsorption isotherms. The potential ability of these microspheres for selectively capturing and labeling target biological molecules was evaluated by using protein-digestion analysis and a real sample as well as by comparison with the widely used TiO(2) affinity microspheres. These results show that these porous rare-earth phosphate microspheres are highly promising probes for the rapid purification and recognition of phosphopeptides.

  2. Sub-parts-per-billion determination of nitro-substituted polynuclear aromatic hydrocarbons in airborne particulate matter and soil by electron capture-Tandem mass spectrometry.

    Science.gov (United States)

    Vincenti, M; Minero, C; Pelizzetti, E; Fontana, M; De Maria, R

    1996-12-01

    A procedure for the determination of nitro-substiruted polynuclear aromatic hydrocarbons (nitro-PAH) on crude air-particulate and soil extracts is introduced. Elimination of purification and fractionation procedures was made possible by the use of both a selective ionization method, such as electron-capture chemical ionization, and a specific fragmentation process, in an experiment of tandem mass spectrometry (gas chromatography-electron capture tandem mass spectrometry). Different mass spectrometric procedures were compared. The best performance was observed when the nitro-PAH molecular ions [M](-) were mass-selected by the first analyzer under multiple reaction monitoring conditions and then fragmented to NO 2 (-) (m/z 46). Detection limits were on the order of hundreds of femtograms, as determined in extracts of real environmental samples. This corresponds approximately to 5-15 pg of nitro-PAH per cubic meter of air sampled. Calibration curves were linear over 3 orders of magnitude. Applications to contamination from motor vehicle combustion and the iron industry are briefly discussed.

  3. Affinity capture of biotinylated proteins at acidic conditions to facilitate hydrogen/deuterium exchange mass spectrometry analysis of multimeric protein complexes

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Jørgensen, Thomas J. D.; Koefoed, Klaus;

    2013-01-01

    prior to the HDX-MS experiment. However, when studying protein complexes of more than two proteins, immobilization can possibly introduce steric limitations to the interactions. Here, we present a method based on the high affinity biotin-streptavidin interaction that allows selective capture...... of biotinylated proteins even under the extreme conditions for hydrogen/deuterium exchange quenching i.e. pH 2.5 and 0 °C. This biotin-streptavidin capture strategy allows hydrogen/deuterium exchange to occur in proteins in solution and enables characterization of specific proteins in heteromultimeric protein...... complexes without interference of peptides originating from other interaction partners in the complex. The biotin-streptavidin strategy has been successfully implemented in a model system with two recombinant monoclonal antibodies that target nonoverlapping epitopes on the human epidermal growth factor...

  4. Synthesis of Biotinylated Inositol Hexakisphosphate To Study DNA Double-Strand Break Repair and Affinity Capture of IP6-Binding Proteins.

    Science.gov (United States)

    Jiao, Chensong; Summerlin, Matthew; Bruzik, Karol S; Hanakahi, Leslyn

    2015-10-20

    Inositol hexakisphosphate (IP6) is a soluble inositol polyphosphate, which is abundant in mammalian cells. Despite the participation of IP6 in critical cellular functions, few IP6-binding proteins have been characterized. We report on the synthesis, characterization, and application of biotin-labeled IP6 (IP6-biotin), which has biotin attached at position 2 of the myo-inositol ring via an aminohexyl linker. Like natural IP6, IP6-biotin stimulated DNA ligation by nonhomologous end joining (NHEJ) in vitro. The Ku protein is a required NHEJ factor that has been shown to bind IP6. We found that IP6-biotin could affinity capture Ku and other required NHEJ factors from human cell extracts, including the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), XRCC4, and XLF. Direct binding studies with recombinant proteins show that Ku is the only NHEJ factor with affinity for IP6-biotin. DNA-PKcs, XLF, and the XRCC4:ligase IV complex interact with Ku in cell extracts and likely interact indirectly with IP6-biotin. IP6-biotin was used to tether streptavidin to Ku, which inhibited NHEJ in vitro. These proof-of-concept experiments suggest that molecules like IP6-biotin might be used to molecularly target biologically important proteins that bind IP6. IP6-biotin affinity capture experiments show that numerous proteins specifically bind IP6-biotin, including casein kinase 2, which is known to bind IP6, and nucleolin. Protein binding to IP6-biotin is selective, as IP3, IP4, and IP5 did not compete for binding of proteins to IP6-biotin. Our results document IP6-biotin as a useful tool for investigating the role of IP6 in biological systems.

  5. Validation of a Liquid Chromatography Tandem Mass Spectrometry Method for Targeted Degradation Compounds of Ethanolamine Used in CO2 Capture: Application to Real Samples

    Directory of Open Access Journals (Sweden)

    Cuzuel Vincent

    2014-09-01

    Full Text Available In the field of greenhouse gas emission, a promising approach consists in CO2 storage and capture. However most of the processes are based on amine solutions which are likely to degrade and produce potentially harmful compounds. So there is a need for analytical methods to identify and quantify these products. Monoethanolamine was used as a model compound for the amines used for CO2 capture. A liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of six products of degradation of monoethanolamine (Glycine, N-(2-hydroxyethylglycine, N-glycylglycine, bicine, N,N′-bis-(2-hydroxyethyl urea (BHE Urea, and diethanolamine that were systematically detected with a LC-MS Scan method in real samples from CO2 capture and storage processes. The main difficulty of this study and its originality ly in the strategy developed to overcome the complexity of the matrix which is a mix of water and amine (70/30: the combined use of deuterated internal standards and a recent chemiometric approach to validate the method, i.e. the accuracy profile. For five compounds it was possible to validate the method with acceptance limits of 20%. This method was then successfully applied to real samples from pilot plant and lab-scale experiments.

  6. Sensitive and label-free biosensing of RNA with predicted secondary structures by a triplex affinity capture method

    Science.gov (United States)

    Carrascosa, Laura G.; Gómez-Montes, S.; Aviñó, A.; Nadal, A.; Pla, M.; Eritja, R.; Lechuga, L. M.

    2012-01-01

    A novel biosensing approach for the label-free detection of nucleic acid sequences of short and large lengths has been implemented, with special emphasis on targeting RNA sequences with secondary structures. The approach is based on selecting 8-aminoadenine-modified parallel-stranded DNA tail-clamps as affinity bioreceptors. These receptors have the ability of creating a stable triplex-stranded helix at neutral pH upon hybridization with the nucleic acid target. A surface plasmon resonance biosensor has been used for the detection. With this strategy, we have detected short DNA sequences (32-mer) and purified RNA (103-mer) at the femtomol level in a few minutes in an easy and level-free way. This approach is particularly suitable for the detection of RNA molecules with predicted secondary structures, reaching a limit of detection of 50 fmol without any label or amplification steps. Our methodology has shown a marked enhancement for the detection (18% for short DNA and 54% for RNA), when compared with the conventional duplex approach, highlighting the large difficulty of the duplex approach to detect nucleic acid sequences, especially those exhibiting stable secondary structures. We believe that our strategy could be of great interest to the RNA field. PMID:22241768

  7. SILAC-iPAC: a quantitative method for distinguishing genuine from non-specific components of protein complexes by parallel affinity capture.

    Science.gov (United States)

    Rees, Johanna S; Lilley, Kathryn S; Jackson, Antony P

    2015-02-06

    Pull-down assays can identify members of protein complexes but suffer from co-isolation of contaminants. The problem is particularly acute when the specifically interacting partners are of low-abundance and/or bind transiently with low affinity. To differentiate true interacting partners from contaminants, we have combined SILAC labelling with a proteomic method called "Interactomes by Parallel Affinity Capture" (iPAC). In our method, a cell-line stably expressing a doubly tagged target endogenous protein and its tag-less control cell-line are differentially SILAC labelled. Lysates from the two cell-lines are mixed and the tagged protein is independently purified for MS analysis using multiple affinity resins in parallel. This allows the quantitative identification of tagged proteins and their binding partners. SILAC-iPAC provides a rigorous and sensitive approach that can discriminate between genuine binding partners and contaminants, even when the contaminants in the pull-down are in large excess. We employed our method to examine the interacting partners of phosphatidyl inositol 5-phosphate 4-kinase 2β subunit (PI5P4K2β) and the Fanconi anaemia core complex in the chicken pre-B cell-line DT40. We confirmed known components of these two complexes, and we have identified new potential binding partners. Combining the iPAC approach with SILAC labelling provides a sensitive and fully quantitative method for the discrimination of specific interactions under conditions where low signal to noise ratios are unavoidable. In addition, our work provides the first characterisation of the most abundant proteins within the DT40 proteome and the non-specific DT40 'beadomes' (non-specific proteins binding to beads) for common epitope tags. Given the importance and widespread use of the DT40 cell-line, these will be important resources for the cell biology and immunology communities. Biological significance SILAC-iPAC provides an improved method for the analysis of low-affinity

  8. Ultra-fast liquid chromatography with tandem mass spectrometry determination of ochratoxin A in traditional Chinese medicines based on vortex-assisted solid-liquid microextraction and aptamer-affinity column clean-up.

    Science.gov (United States)

    Yang, Xihui; Hu, Yichen; Kong, Weijun; Chu, Xianfeng; Yang, Meihua; Zhao, Ming; Ouyang, Zhen

    2014-11-01

    A rapid, selective, and sensitive ultra-fast liquid chromatography with tandem mass spectrometry method was developed for the determination of ochratoxin A in traditional Chinese medicines based on vortex-assisted solid-liquid microextraction and aptamer-affinity column clean-up. Through optimizing the sample pretreatment procedures and chromatographic conditions, good linearity (r(2) ≥ 0.9993), low limit of detection (0.5-0.8 μg/kg), and satisfactory recovery (83.54-94.44%) expressed the good reliability and applicability of the established method in various traditional Chinese medicines. Moreover, the aptamer-affinity column, prepared in-house, showed an excellent feasibility owing to its specific identification of ochratoxin A in various kinds of selected traditional Chinese medicines. The maximum adsorption amount and applicability value were 188.96 ± 10.56 ng and 72.3%, respectively. The matrix effects were effectively eliminated, especially for m/z 404.2→358.0 of ochratoxin A. The application of the developed method for screening the natural contamination levels of ochratoxin A in 25 random traditional Chinese medicines on the market in China indicated that only eight samples were contaminated with low levels below the legal limit (5.0 μg/kg) set by the European Union. This study provided a preferred choice for the rapid and accurate monitoring of ochratoxin A in complex matrices.

  9. Simultaneous analysis of polychlorinated biphenyls and organochlorine pesticides in seawater samples by membrane-assisted solvent extraction combined with gas chromatography-electron capture detector and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Shi, Xizhi; Tang, Zigang; Sun, Aili; Zhou, Lei; Zhao, Jian; Li, Dexiang; Chen, Jiong; Pan, Daodong

    2014-12-01

    A highly efficient and environment-friendly membrane-assisted solvent extraction system combined with gas chromatography-electron capture detector was applied in the simultaneous determination of 17 polychlorinated biphenyls and organochlorine pesticides in seawater samples. Variables affecting extraction efficiency, including extraction solvent used, stirring rate, extraction time, and temperature, were optimized extensively. Under optimal extraction conditions, recoveries between 76.9% and 104.6% in seawater samples were achieved, and relative standard deviation values below 10% were obtained. The limit of detection (signal-to-noise ratio=3) and limit of quantification (signal-to-noise ratio=10) of 17 polychlorinated biphenyls and organochlorine pesticides in seawater ranged from 0.14ngL(-1) to 0.36ngL(-1) and 0.46ngL(-1) to 1.19ngL(-1), respectively. Matrix effects on extraction efficiency were evaluated by comparing with the results obtained using tap water. The extraction effect of developed membrane-assisted solvent extraction method was further demonstrated by gas chromatography-tandem mass spectrometry which can provide structural information of the analytes for more accurate identification, and results identical to those produced by gas chromatography-electron capture detector were obtained. These findings demonstrate the applicability of the developed membrane-assisted solvent extraction determination method for coupling to gas chromatography-electron capture detector or tandem mass spectrometry for determining polychlorinated biphenyls and organochlorine pesticides in seawater samples.

  10. Evaluation of immobilized metal-ion affinity chromatography and electrospray ionization tandem mass spectrometry for recovery and identification of copper(II-binding ligands in seawater using the model ligand 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Richard L Nixon

    2016-11-01

    Full Text Available Complexation by organic ligands dominates the speciation of iron (Fe, copper (Cu, and other bioactive trace metals in seawater, controlling their bioavailability and distribution in the marine environment. Several classes of high-affinity Fe-binding ligands (siderophores have been identified in seawater but the chemical structures of marine Cu-complexing ligands remain unknown. Immobilized metal-ion affinity chromatography (IMAC allows Cu ligands to be isolated from bulk dissolved organic matter (DOM in seawater and separated into fractions which can be characterized independently using electrochemical and spectroscopic techniques. Attempts have been made to combine IMAC with electrospray ionization mass spectrometry (ESI-MS to characterize marine Cu ligands, but results have proven inconclusive due to the lack of tandem mass spectrometry (MS/MS data to confirm ligand recovery. We used 8-hydroxyquinoline (8-HQ, a well-characterized model ligand that forms strong 1:2 metal:ligand complexes with Cu2+ at pH 8 (log β2 = 18.3, to evaluate Cu(II-IMAC and ESI-MS/MS for recovery and identification of copper(II-complexing ligands in seawater. One-litre samples of 0.45µm-filtered surface seawater were spiked with 8-HQ at low concentrations (up to 100 nM and fractionated by IMAC. Fractions eluted with acidified artificial seawater were desalted and re-suspended in methanol via solid-phase extraction (SPE to obtain extracts suitable for ESI-MS analysis. Recovery of 8-HQ by Cu(II-IMAC was confirmed unambiguously by MS/MS and found to average 81% based upon accurate quantitation via multiple reaction monitoring (MRM. Cu(II-IMAC fractionation of unspiked seawater using multiple UV detection wavelengths suggests an optimal fraction size of 2 mL for isolating and analyzing Cu ligands with similar properties.

  11. 串联亲和纯化技术及其在植物蛋白质组研究中的应用%Tandem affinity purification technology and its applications in plant proteomic research

    Institute of Scientific and Technical Information of China (English)

    王丰青; 吴为人; 陈新建; 李娟; 周艳; 张重义

    2013-01-01

    Tandem affinity purification (TAP) is a novel technology for protein complex purification,which has been extensively utilized for the identification or verification of protein-protein interactions and the construction of protein interaction networks.Its basic principle is that the TAP tag is fused to the target protein of interest and then the TAP-tagged protein together with any associated proteins are isolated from the host organism in two sequential affinity purification steps.Initially,TAP technology was mainly used in animals and microbes.But in recent years,more and more applications of TAP technology in plants have been reported with the emergence of new TAP tags and optimized methods,providing an efficient tool for plant proteomics.This paper briefly introduced the application of the TAP method on plants,and analyzed limiting factors in its application.%串联亲和纯化(TAP)是一项新颖的蛋白质复合物纯化技术,已被广泛应用于鉴定或验证蛋白质间的相互作用以及建立蛋白质互作网络,其基本原理是,将TAP标签融合到目标蛋白上,然后经过两步亲和纯化,获得融合蛋白及其结构关联蛋白.TAP技术最初主要在动物和微生物中应用.近几年来,随着新型标签的出现和方法的改进,TAP技术在植物中的应用逐渐增多,为植物蛋白质组学的研究提供了一个有效的手段.简要介绍TAP方法在植物中的应用情况,并对TAP方法应用的限制因素进行分析.

  12. An Inducible Retroviral Expression System for Tandem Affinity Purification Mass-Spectrometry-Based Proteomics Identifies Mixed Lineage Kinase Domain-like Protein (MLKL) as an Heat Shock Protein 90 (HSP90) Client.

    Science.gov (United States)

    Bigenzahn, Johannes W; Fauster, Astrid; Rebsamen, Manuele; Kandasamy, Richard K; Scorzoni, Stefania; Vladimer, Gregory I; Müller, André C; Gstaiger, Matthias; Zuber, Johannes; Bennett, Keiryn L; Superti-Furga, Giulio

    2016-03-01

    Tandem affinity purification-mass spectrometry (TAP-MS) is a popular strategy for the identification of protein-protein interactions, characterization of protein complexes, and entire networks. Its employment in cellular settings best fitting the relevant physiology is limited by convenient expression vector systems. We developed an easy-to-handle, inducible, dually selectable retroviral expression vector allowing dose- and time-dependent control of bait proteins bearing the efficient streptavidin-hemagglutinin (SH)-tag at their N- or C termini. Concomitant expression of a reporter fluorophore allows to monitor bait-expressing cells by flow cytometry or microscopy and enables high-throughput phenotypic assays. We used the system to successfully characterize the interactome of the neuroblastoma RAS viral oncogene homolog (NRAS) Gly12Asp (G12D) mutant and exploited the advantage of reporter fluorophore expression by tracking cytokine-independent cell growth using flow cytometry. Moreover, we tested the feasibility of studying cytotoxicity-mediating proteins with the vector system on the cell death-inducing mixed lineage kinase domain-like protein (MLKL) Ser358Asp (S358D) mutant. Interaction proteomics analysis of MLKL Ser358Asp (S358D) identified heat shock protein 90 (HSP90) as a high-confidence interacting protein. Further phenotypic characterization established MLKL as a novel HSP90 client. In summary, this novel inducible expression system enables SH-tag-based interaction studies in the cell line proficient for the respective phenotypic or signaling context and constitutes a valuable tool for experimental approaches requiring inducible or traceable protein expression.

  13. 人肠三叶因子串联亲和层析表达载体的构建与表达%Construction and expression of trefoil factor 3 expressing vector for tandem affinity purification

    Institute of Scientific and Technical Information of China (English)

    黄建坤; 王琳; 裴一花; 刘国彦

    2015-01-01

    BACKGROUND:As a novel growth factor, human intestinal trefoil factor (TFF3) can promote cel growth and migration, and increase cel resistance to apoptosis, and it plays a great role in maintaining the mucosa integrity, mucosa protection and repairing the injured mucosa, also it has been closely related to the tumor growth and progression. With the function of mucosa repair, and as the tumor biomarker, TFF3 has a promising clinical application, but its definite interacting protein and molecular mechanism is stil unclear. OBJECTIVE:To construct and express the TFF3 recombinant protein with the tandem tag of StrepII-6×His in the target cel s for further purifying its interaction protein in the native condition based on the tandem affinity purification technique. METHODS:The DNA sequence for the tag (StrepII-TEV-6×His) and TFF3 as template was got by chemical synthesis and PCR amplification respectively. They were fused by the restriction enzyme XbaI site, and the tag sequence was located at the C terminus of TFF3 protein. TFF3-tag fusion gene was cloned into the pCDNA3.0 using EcoRI+HindIII, thus the TFF3-tag expressing vector pTFF3-C-StH was constructed and transfected transiently into gastric cel AGS by lipofectin. The recombinant TFF3-tag protein was expressed and detected by western blot assay. RESULTS AND CONCLUSION:The expressing vector pTFF3-C-StH for tandem affinity purification was constructed successful y, and was confirmed further by restriction enzyme analysis and sequenced. The recombinant TFF3-C-StH protein of TFF3-tag was expressed in the AGS cel , and showed specific antigenicity by western blot assay. Thus this work provides experimental base for further purification of the TFF3 interacting proteins.%背景:人肠三叶因子为新型的生长因子,可促进细胞生长与迁移,并使细胞具有很强抗凋亡能力,在维持胃肠黏膜完整性、黏膜保护与损伤修复发挥着重要作用,与胃肠道等多个肿瘤的发生

  14. High affinity capture and concentration of quinacrine in polymorphonuclear neutrophils via vacuolar ATPase-mediated ion trapping: Comparison with other peripheral blood leukocytes and implications for the distribution of cationic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Caroline; Gagné, Valérie; Fernandes, Maria J.G.; Marceau, François, E-mail: francois.marceau@crchul.ulaval.ca

    2013-07-15

    Many cationic drugs are concentrated in acidic cell compartments due to low retro-diffusion of the protonated molecule (ion trapping), with an ensuing vacuolar and autophagic cytopathology. In solid tissues, there is evidence that phagocytic cells, e.g., histiocytes, preferentially concentrate cationic drugs. We hypothesized that peripheral blood leukocytes could differentially take up a fluorescent model cation, quinacrine, depending on their phagocytic competence. Quinacrine transport parameters were determined in purified or total leukocyte suspensions at 37 °C. Purified polymorphonuclear leukocytes (PMNLs, essentially neutrophils) exhibited a quinacrine uptake velocity inferior to that of lymphocytes, but a consistently higher affinity (apparent K{sub M} 1.1 vs. 6.3 μM, respectively). However, the vacuolar (V)-ATPase inhibitor bafilomycin A1 prevented quinacrine transport or initiated its release in either cell type. PMNLs capture most of the quinacrine added at low concentrations to fresh peripheral blood leukocytes compared with lymphocytes and monocytes (cytofluorometry). Accumulation of the autophagy marker LC3-II occurred rapidly and at low drug concentrations in quinacrine-treated PMNLs (significant at ≥ 2.5 μM, ≥ 2 h). Lymphocytes contained more LAMP1 than PMNLs, suggesting that the mass of lysosomes and late endosomes is a determinant of quinacrine uptake V{sub max}. PMNLs, however, exhibited the highest capacity for pinocytosis (uptake of fluorescent dextran into endosomes). The selectivity of quinacrine distribution in peripheral blood leukocytes may be determined by the collaboration of a non-concentrating plasma membrane transport mechanism, tentatively identified as pinocytosis in PMNLs, with V-ATPase-mediated concentration. Intracellular reservoirs of cationic drugs are a potential source of toxicity (e.g., loss of lysosomal function in phagocytes). - Highlights: • Quinacrine is concentrated in acidic organelles via V-ATPase-mediated ion

  15. Determination of acrylamide in Chinese traditional carbohydrate-rich foods using gas chromatography with micro-electron capture detector and isotope dilution liquid chromatography combined with electrospray ionization tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yu [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China); Ren Yiping [Zhejiang Provincial Center for Disease Prevention and Control, Hangzhou 310009, Zhejiang Province (China); Zhao Hangmei [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China); Zhang Ying [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China)]. E-mail: y_zhang@zju.edu.cn

    2007-02-19

    The present study developed two analytical methods for quantification of acrylamide in complex food matrixes, such as Chinese traditional carbohydrate-rich foods. One is based on derivatization with potassium bromate and potassium bromide without clean-up prior to gas chromatography with micro-electron capture detector (GC-MECD). Alternatively, the underivatized acrylamide was detected by high-performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization mode. For both methods, the Chinese carbohydrate-rich samples were homogenized, defatted with petroleum ether and extracted with aqueous solution of sodium chloride. Recovery rates for acrylamide from spiked Chinese style foods with the spiking level of 50, 500 and 1000 {mu}g kg{sup -1} were in the range of 79-93% for the GC-MECD including derivatization and 84-97% for the HPLC-MS/MS method. Typical quantification limits of the HPLC-MSMS method were 4 {mu}g kg{sup -1} for acrylamide. The GC-MECD method achieved quantification limits of 10 {mu}g kg{sup -1} in Chinese style foods. Thirty-eight Chinese traditional foods purchased from different manufacturers were analyzed and compared with four Western style foods. Acrylamide contaminant was found in all of samples at the concentration up to 771.1 and 734.5 {mu}g kg{sup -1} detected by the GC and HPLC method, respectively. The concentrations determined with the two different quantitative methods corresponded well with each other. A convenient and fast pretreatment procedure will be optimized in order to satisfy further investigation of hundreds of samples.

  16. Determination of acrylamide in Chinese traditional carbohydrate-rich foods using gas chromatography with micro-electron capture detector and isotope dilution liquid chromatography combined with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Yu; Ren, Yiping; Zhao, Hangmei; Zhang, Ying

    2007-02-19

    The present study developed two analytical methods for quantification of acrylamide in complex food matrixes, such as Chinese traditional carbohydrate-rich foods. One is based on derivatization with potassium bromate and potassium bromide without clean-up prior to gas chromatography with micro-electron capture detector (GC-MECD). Alternatively, the underivatized acrylamide was detected by high-performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization mode. For both methods, the Chinese carbohydrate-rich samples were homogenized, defatted with petroleum ether and extracted with aqueous solution of sodium chloride. Recovery rates for acrylamide from spiked Chinese style foods with the spiking level of 50, 500 and 1000 microg kg(-1) were in the range of 79-93% for the GC-MECD including derivatization and 84-97% for the HPLC-MS/MS method. Typical quantification limits of the HPLC-MSMS method were 4 microg kg(-1) for acrylamide. The GC-MECD method achieved quantification limits of 10 microg kg(-1) in Chinese style foods. Thirty-eight Chinese traditional foods purchased from different manufacturers were analyzed and compared with four Western style foods. Acrylamide contaminant was found in all of samples at the concentration up to 771.1 and 734.5 microg kg(-1) detected by the GC and HPLC method, respectively. The concentrations determined with the two different quantitative methods corresponded well with each other. A convenient and fast pretreatment procedure will be optimized in order to satisfy further investigation of hundreds of samples.

  17. Capturing Thoughts, Capturing Minds?

    DEFF Research Database (Denmark)

    Nielsen, Janni

    2004-01-01

    Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention...

  18. A Novel Vertex Affinity for Community Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.

  19. Capture Matrices Handbook

    Science.gov (United States)

    2014-04-01

    changing the affinity ligand, we can use capture matrices to detect other chemicals such as chlorinated solvents, nerve and blister agents, pesticides...require significant chemical additives and complex equipment, generate a large secondary waste stream, and are difficult to automate. Magnetically...secondary wastes . 2 Other advantages are a large active surface area for a given mass of particles; the ability to process a solution that

  20. Affinity filtration coupled with capillary-based affinity purification for the isolation of protein complexes.

    Science.gov (United States)

    Qureshi, M S; Sheikh, Q I; Hill, R; Brown, P E; Dickman, M J; Tzokov, S B; Rice, D W; Gjerde, D T; Hornby, D P

    2013-08-01

    The isolation of complex macromolecular assemblies at the concentrations required for structural analysis represents a major experimental challenge. Here we present a method that combines the genetic power of site-specific recombination in order to selectively "tag" one or more components of a protein complex with affinity-based rapid filtration and a final step of capillary-based enrichment. This modified form of tandem affinity purification produces highly purified protein complexes at high concentrations in a highly efficient manner. The application of the method is demonstrated for the yeast Arp2/3 heptameric protein complex involved in mediating reorganization of the actin cytoskeleton.

  1. On affine rigidity

    Directory of Open Access Journals (Sweden)

    Steven J. Gortler

    2013-12-01

    Full Text Available We study the properties of affine rigidity of a hypergraph and prove a variety of fundamental results. First, we show that affine rigidity is a generic property (i.e., depends only on the hypergraph, not the particular embedding. Then we prove that a graph is generically neighborhood affinely rigid in d-dimensional space if it is (d+1-vertex-connected. We also show neighborhood affine rigidity of a graph implies universal rigidity of its squared graph.  Our results, and affine rigidity more generally, have natural applications in point registration and localization, as well as connections to manifold learning.

  2. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation proces

  3. Tandem Cylinder Noise Predictions

    Science.gov (United States)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  4. Affine Dynamics with Torsion

    CERN Document Server

    Gultekin, Kemal

    2015-01-01

    In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on determinants of the Ricci tensor, torsion tensor, Riemann tensor and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to construction of the affine connection in terms of curvature and torsion tensors. Our solutions of the dynamical equations show that curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor.

  5. Affinity in electrophoresis.

    Science.gov (United States)

    Heegaard, Niels H H

    2009-06-01

    The journal Electrophoresis has greatly influenced my approaches to biomolecular affinity studies. The methods that I have chosen as my main tools to study interacting biomolecules--native gel and later capillary zone electrophoresis--have been the topic of numerous articles in Electrophoresis. Below, the role of the journal in the development and dissemination of these techniques and applications reviewed. Many exhaustive reviews on affinity electrophoresis and affinity CE have been published in the last few years and are not in any way replaced by the present deliberations that are focused on papers published by the journal.

  6. Tandem mobile robot system

    Energy Technology Data Exchange (ETDEWEB)

    Buttz, James H. (Albuquerque, NM); Shirey, David L. (Albuquerque, NM); Hayward, David R. (Albuquerque, NM)

    2003-01-01

    A robotic vehicle system for terrain navigation mobility provides a way to climb stairs, cross crevices, and navigate across difficult terrain by coupling two or more mobile robots with a coupling device and controlling the robots cooperatively in tandem.

  7. Affine dynamics with torsion

    Energy Technology Data Exchange (ETDEWEB)

    Gueltekin, Kemal [Izmir Institute of Technology, Department of Physics, Izmir (Turkey)

    2016-03-15

    In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on the determinants of the Ricci tensor, the torsion tensor, the Riemann tensor, and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to the construction of the affine connection in terms of the curvature and torsion tensors. Our solutions of the dynamical equations show that the curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor. (orig.)

  8. Affine and degenerate affine BMW algebras: Actions on tensor space

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2012-01-01

    The affine and degenerate affine Birman-Murakami-Wenzl (BMW) algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic quantum groups and Lie algebras, respectively. Cyclotomic BMW algebras, affine and cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper we explain how the affine and degenerate affine BMW algebras are tantalizers (tensor power centralizer algebras) by defining actions of the affine braid group and the degenerate affine braid algebra on tensor space and showing that, in important cases, these actions induce actions of the affine and degenerate affine BMW algebras. We then exploit the connection to quantum groups and Lie algebras to determine universal parameters for the affine and degenerate affine BMW algebras. Finally, we show that the universal parameters are central elements--the higher Casimir elements for orthogonal and symplectic enveloping algebras and quantum groups.

  9. Capturing appearance

    Science.gov (United States)

    Rushmeier, Holly E.

    2005-01-01

    For computer graphics applications, capturing the appearance parameters of objects (reflectance, transmittance and small scale surface structures), is as important as capturing the overall shape. We briefly review recent approaches developed by the computer graphics community to solve this problem. Excellent results have been obtained by various researchers measuring spatially varying reflectance functions for some classes of objects. We will consider some challenges from two of the remaining problematic classes of objects. First we will describe our experience scanning and modeling the throne of Tutankhamen. The major difficulties in this case were that the base shape was a highly detailed non-convex geometry with complex topology, and the shape was covered by optically uncooperative gold and silver. Then we will discuss some observations from our ongoing project to scan and model historic buildings on the Yale campus. The major difficulties in this second case are quantity of data and the lack of control over acquisition conditions.

  10. Affinity Purification of Protein Complexes Using TAP Tags

    Science.gov (United States)

    Gerace, Erica; Moazed, Danesh

    2016-01-01

    This protocol is used for the isolation and analysis of protein complexes using the tandem affinity purification (TAP) tag system. The protocol describes the purification of a protein fused to a TAP tag comprised of two protein A domains and the calmodulin binding peptide separated by a TEV cleavage site. This is a powerful technique for rapid purification of protein complexes and the analysis of their stoichiometric composition, posttranslational modifications, structure, and functional activities. PMID:26096502

  11. Affine Sphere Relativity

    Science.gov (United States)

    Minguzzi, E.

    2016-11-01

    We investigate spacetimes whose light cones could be anisotropic. We prove the equivalence of the structures: (a) Lorentz-Finsler manifold for which the mean Cartan torsion vanishes, (b) Lorentz-Finsler manifold for which the indicatrix (observer space) at each point is a convex hyperbolic affine sphere centered on the zero section, and (c) pair given by a spacetime volume and a sharp convex cone distribution. The equivalence suggests to describe (affine sphere) spacetimes with this structure, so that no algebraic-metrical concept enters the definition. As a result, this work shows how the metric features of spacetime emerge from elementary concepts such as measure and order. Non-relativistic spacetimes are obtained replacing proper spheres with improper spheres, so the distinction does not call for group theoretical elements. In physical terms, in affine sphere spacetimes the light cone distribution and the spacetime measure determine the motion of massive and massless particles (hence the dispersion relation). Furthermore, it is shown that, more generally, for Lorentz-Finsler theories non-differentiable at the cone, the lightlike geodesics and the transport of the particle momentum over them are well defined, though the curve parametrization could be undefined. Causality theory is also well behaved. Several results for affine sphere spacetimes are presented. Some results in Finsler geometry, for instance in the characterization of Randers spaces, are also included.

  12. Affine stochastic mortality

    NARCIS (Netherlands)

    D.F. Schrager

    2006-01-01

    We propose a new model for stochastic mortality. The model is based on the literature on affine term structure models. It satisfies three important requirements for application in practice: analytical tractibility, clear interpretation of the factors and compatibility with financial option pricing m

  13. A generic protocol for the purification and characterization of water-soluble complexes of affinity-tagged proteins and lipids.

    Science.gov (United States)

    Maeda, Kenji; Poletto, Mattia; Chiapparino, Antonella; Gavin, Anne-Claude

    2014-09-01

    Interactions between lipids and proteins in the aqueous phases of cells contribute to many aspects of cell physiology. Here we describe a detailed protocol to systematically characterize in vivo-assembled complexes of soluble proteins and lipids. Saccharomyces cerevisiae strains expressing physiological amounts of a protein of interest fused to the tandem-affinity purification (TAP) tag are first lysed in the absence of detergent to capture intact protein-lipid complexes. The affinity-purified complexes (typically 30-50 kDa) are subjected to analytical size-exclusion chromatography (SEC) to remove contaminating lipids that elute at the void volume (>600 kDa), in order to achieve sufficient signal-to-background lipid ratios. Proteins in the SEC fractions are then analyzed by denaturing gel electrophoresis. Lipidomics techniques such as high-performance thin-layer chromatography or gas or liquid chromatography-mass spectrometry can then be applied to measure the elution profiles of lipids and to pinpoint the true interactors co-eluting with the TAP fusions. The procedure (starting from cell lysis) requires 2 d, and it can easily be adapted to other organisms.

  14. Affinity Monolith-Integrated Microchips for Protein Purification and Concentration.

    Science.gov (United States)

    Gao, Changlu; Sun, Xiuhua; Wang, Huaixin; Qiao, Wei; Hu, Bo

    2016-01-01

    Affinity chromatography is a valuable method to purify and concentrate minute amount of proteins. Monoliths with epoxy groups for affinity immobilization were prepared by direct in-situ photopolymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in porogenic solvents consisting of 1-dodecanol and cyclohexanol. By integrating affinity monoliths onto a microfluidic system, targeted biomolecules can be captured and retained on affinity column, while other biomolecules having no specific interactions toward the immobilized ligands flow through the microchannel. Therefore, proteins which remain on the affinity column are purified and concentrated, and then eluted by appropriate solutions and finally, separated by microchip capillary electrophoresis. This integrated microfluidic device has been applied to the purification and separation of specific proteins (FITC-labeled human serum albumin and IgG) in a mixture.

  15. Improved methodology for the affinity isolation of human protein complexes expressed at near endogenous levels

    DEFF Research Database (Denmark)

    Domanski, Michal; Molloy, Kelly; Jiang, Hua;

    2012-01-01

    An efficient and reliable procedure for the capture of affinity-tagged proteins and associated complexes from human cell lines is reported. Through multiple optimizations, high yield and low background affinity-purifications are achieved from modest quantities of human cells expressing endogenous......-level tagged proteins. Isolations of triple-FLAG and GFP-tagged fusion proteins involved in RNA metabolism are presented.......An efficient and reliable procedure for the capture of affinity-tagged proteins and associated complexes from human cell lines is reported. Through multiple optimizations, high yield and low background affinity-purifications are achieved from modest quantities of human cells expressing endogenous...

  16. Affine and degenerate affine BMW algebras: The center

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2011-01-01

    The degenerate affine and affine BMW algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic Lie algebras and quantum groups, respectively. Cyclotomic BMW algebras, affine Hecke algebras, cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper the theory is unified by treating the orthogonal and symplectic cases simultaneously; we make an exact parallel between the degenerate affine and affine cases via a new algebra which takes the role of the affine braid group for the degenerate setting. A main result of this paper is an identification of the centers of the affine and degenerate affine BMW algebras in terms of rings of symmetric functions which satisfy a "cancellation property" or "wheel condition" (in the degenerate case, a reformulation of a result of Nazarov). Miraculously, these same rings also arise in Schubert calculus, as the cohomology and K-theory of isotropic Grassmanians and symplectic loop Grassmanians. We also establish new inte...

  17. Flow field interactions between two tandem cyclists

    Science.gov (United States)

    Barry, Nathan; Burton, David; Sheridan, John; Thompson, Mark; Brown, Nicholas A. T.

    2016-12-01

    Aerodynamic drag is the primary resistive force acting on cyclists at racing speeds. Many events involve cyclists travelling in very close proximity. Previous studies have shown that interactions result in significant drag reductions for inline cyclists. However, the interaction between cyclist leg position (pedalling) and the vortical flow structures that contribute significantly to the drag on an isolated cyclist has not previously been quantified or described for tandem cyclists of varying separation. To this end, scale model cyclists were constructed for testing in a water channel for inline tandem configurations. Particle image velocimetry was used to capture time-averaged velocity fields around two tandem cyclists. Perhaps surprisingly, the wake of a trailing cyclist maintains strong similarity to the characteristic wake of a single cyclist despite a significant disturbance to the upstream flow. Together with streamwise velocity measurements through the wake and upstream of the trailing cyclist, this work supports previous findings, which showed that the trailing cyclist drag reduction is primarily due to upstream sheltering effects reducing the stagnation pressure on forward-facing surfaces.

  18. Hierarchical Affinity Propagation

    CERN Document Server

    Givoni, Inmar; Frey, Brendan J

    2012-01-01

    Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...

  19. Artificial Affinity Proteins as Ligands of Immunoglobulins

    Directory of Open Access Journals (Sweden)

    Barbara Mouratou

    2015-01-01

    Full Text Available A number of natural proteins are known to have affinity and specificity for immunoglobulins. Some of them are widely used as reagents for detection or capture applications, such as Protein G and Protein A. However, these natural proteins have a defined spectrum of recognition that may not fit specific needs. With the development of combinatorial protein engineering and selection techniques, it has become possible to design artificial affinity proteins with the desired properties. These proteins, termed alternative scaffold proteins, are most often chosen for their stability, ease of engineering and cost-efficient recombinant production in bacteria. In this review, we focus on alternative scaffold proteins for which immunoglobulin binders have been identified and characterized.

  20. Affinity driven social networks

    Science.gov (United States)

    Ruyú, B.; Kuperman, M. N.

    2007-04-01

    In this work we present a model for evolving networks, where the driven force is related to the social affinity between individuals of a population. In the model, a set of individuals initially arranged on a regular ordered network and thus linked with their closest neighbors are allowed to rearrange their connections according to a dynamics closely related to that of the stable marriage problem. We show that the behavior of some topological properties of the resulting networks follows a non trivial pattern.

  1. Purely affine Gravity

    CERN Document Server

    Skirzewski, Aureliano

    2014-01-01

    We develop a topological theory of gravity with torsion where metric has a dynamical rather than a kinematical origin. This approach towards gravity resembles pre-geometrical approaches in which a fundamental metric does not exist, but the affine connection gives place to a local inertial structure. Such feature reminds us of Mach's principle, that assumes the inertial forces should have dynamical origin. Additionally, a Newtonian gravitational force is obtained in the non-relativistic limit of the theory.

  2. Affine morphisms at zero level

    CERN Document Server

    Das, Paramita; Gupta, Ved Prakash

    2010-01-01

    Given a finite index subfactor, we show that the {\\em affine morphisms at zero level} in the affine category over the planar algebra associated to the subfactor is isomorphic to the fusion algebra of the subfactor as a *-algebra.

  3. On the Affine Isoperimetric Inequalities

    Indian Academy of Sciences (India)

    Wuyang Yu; Gangsong Leng

    2011-11-01

    We obtain an isoperimetric inequality which estimate the affine invariant -surface area measure on convex bodies. We also establish the reverse version of -Petty projection inequality and an affine isoperimetric inequality of $_{-p}K$.

  4. Affine Patches on Positroid Varieties and Affine Pipe Dreams (Thesis)

    CERN Document Server

    Snider, Michelle

    2010-01-01

    The objects of interest in this thesis are positroid varieties in the Grassmannian, which are indexed by juggling patterns. In particular, we study affine patches on these positroid varieties. Our main result corresponds these affine patches to Kazhdan-Lusztig varieties in the affine Grassmannian. We develop a new term order and study how these spaces are related to subword complexes and Stanley-Reisner ideals. We define an extension of pipe dreams to the affine case and conclude by showing how our affine pipe dreams are generalizations of Cauchon and Le diagrams.

  5. Affine and quasi-affine frames for rational dilations

    DEFF Research Database (Denmark)

    Bownik, Marcin; Lemvig, Jakob

    2011-01-01

    , the corresponding family of quasi-affine systems are frames with uniform frame bounds. We also prove a similar equivalence result between pairs of dual affine frames and dual quasi-affine frames. Finally, we uncover some fundamental differences between the integer and rational settings by exhibiting an example......In this paper we extend the investigation of quasi-affine systems, which were originally introduced by Ron and Shen [J. Funct. Anal. 148 (1997), 408-447] for integer, expansive dilations, to the class of rational, expansive dilations. We show that an affine system is a frame if, and only if...

  6. Atmospheric pressure ionization-tandem mass spectrometry of the phenicol drug family.

    Science.gov (United States)

    Alechaga, Élida; Moyano, Encarnación; Galceran, M Teresa

    2013-11-01

    In this work, the mass spectrometry behaviour of the veterinary drug family of phenicols, including chloramphenicol (CAP) and its related compounds thiamphenicol (TAP), florfenicol (FF) and FF amine (FFA), was studied. Several atmospheric pressure ionization sources, electrospray (ESI), atmospheric pressure chemical ionization and atmospheric pressure photoionization were compared. In all atmospheric pressure ionization sources, CAP, TAP and FF were ionized in both positive and negative modes; while for the metabolite FFA, only positive ionization was possible. In general, in positive mode, [M + H](+) dominated the mass spectrum for FFA, while the other compounds, CAP, TAP and FF, with lower proton affinity showed intense adducts with species present in the mobile phase. In negative mode, ESI and atmospheric pressure photoionization showed the deprotonated molecule [M-H](-), while atmospheric pressure chemical ionization provided the radical molecular ion by electron capture. All these ions were characterized by tandem mass spectrometry using the combined information obtained by multistage mass spectrometry and high-resolution mass spectrometry in a quadrupole-Orbitrap instrument. In general, the fragmentation occurred via cyclization and losses or fragmentation of the N-(alkyl)acetamide group, and common fragmentation pathways were established for this family of compounds. A new chemical structure for the product ion at m/z 257 for CAP, on the basis of the MS(3) and MS(4) spectra is proposed. Thermally assisted ESI and selected reaction monitoring are proposed for the determination of these compounds by ultra high-performance liquid chromatography coupled to tandem mass spectrometry, achieving instrumental detection limits down to 0.1 pg.

  7. Affinity Purification of Insulin by Peptide-Ligand Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The affinity heptapeptide (HWWWPAS) for insulin, selected from phage display library,was coupled to EAH Sepharose 4B gel and packed to a 1-mL column. The column was used for the affinity purification of insulin from protein mixture and commercial insulin preparation. It was observed that the minor impurity in the commercial insulin was removed by the affinity chromatography. Nearly 40 mg of insulin could be purified with the 1-mL affinity column. The results revealed the high specificity and capacity of the affinity column for insulin purification. Moreover, based on the analysis of the amino acids in the peptide sequence, shorter peptides were designed and synthesized for insulin chromatography. As a result, HWWPS was found to be a good alternative to HWWWPAS, while the other two peptides with three or four amino acids showed weak affinity for insulin. The results indicated that the peptide sequence of HWWWPAS was quite conservative for specific binding of insulin.

  8. Bifacial tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wojtczuk, Steven J.; Chiu, Philip T.; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2016-06-14

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  9. Jacobi Structures on Affine Bundles

    Institute of Scientific and Technical Information of China (English)

    J. GRABOWSKI; D. IGLESIAS; J. C. MARRERO; E. PADR(O)N; P. URBA(N)SKI

    2007-01-01

    We study affine Jacobi structures (brackets) on an affine bundle π: A→M, i.e. Jacobi brackets that close on affine functions. We prove that if the rank of A is non-zero, there is a one-to- one correspondence between affine Jacobi structures on A and Lie algebroid structures on the vector bundle A+=∪p∈M Aff(Ap, R) of affine functionals. In the case rank A = 0, it is shown that there is a one-to-one correspondence between affins Jacobi structures on A and local Lie algebras on A+. Some examples and applications, also for the linear case, are discussed. For a special type of affine Jacobi structures which are canonically exhibited (strongly-affine or affine-homogeneous Jacobi structures) over a real vector space of finite dimension, we describe the leaves of its characteristic foliation as the orbits of an affine representation. These afline Jacobi structures can be viewed as an analog of the Kostant-Arnold-LiouviUe linear Poisson structure on the dual space of a real finite-dimensional Lie algebra.

  10. Kernel Affine Projection Algorithms

    Directory of Open Access Journals (Sweden)

    José C. Príncipe

    2008-05-01

    Full Text Available The combination of the famed kernel trick and affine projection algorithms (APAs yields powerful nonlinear extensions, named collectively here, KAPA. This paper is a follow-up study of the recently introduced kernel least-mean-square algorithm (KLMS. KAPA inherits the simplicity and online nature of KLMS while reducing its gradient noise, boosting performance. More interestingly, it provides a unifying model for several neural network techniques, including kernel least-mean-square algorithms, kernel adaline, sliding-window kernel recursive-least squares (KRLS, and regularization networks. Therefore, many insights can be gained into the basic relations among them and the tradeoff between computation complexity and performance. Several simulations illustrate its wide applicability.

  11. Kernel Affine Projection Algorithms

    Science.gov (United States)

    Liu, Weifeng; Príncipe, José C.

    2008-12-01

    The combination of the famed kernel trick and affine projection algorithms (APAs) yields powerful nonlinear extensions, named collectively here, KAPA. This paper is a follow-up study of the recently introduced kernel least-mean-square algorithm (KLMS). KAPA inherits the simplicity and online nature of KLMS while reducing its gradient noise, boosting performance. More interestingly, it provides a unifying model for several neural network techniques, including kernel least-mean-square algorithms, kernel adaline, sliding-window kernel recursive-least squares (KRLS), and regularization networks. Therefore, many insights can be gained into the basic relations among them and the tradeoff between computation complexity and performance. Several simulations illustrate its wide applicability.

  12. Characterization of recruitment through tandem running in an Indian queenless ant Diacamma indicum

    Science.gov (United States)

    Kaur, Rajbir; Joseph, Joby; Anoop, Karunakaran

    2017-01-01

    Tandem running is a primitive recruitment method employed by many ant genera. This study characterizes this behaviour during the recruitment of colony mates to a new nest in an Indian ant Diacamma indicum. Tandem leaders who have knowledge of the new nest lead a single follower at a time, to the destination by maintaining physical contact. In order to characterize tandem running, we captured and analysed 621 invitations, 217 paths and 226 termination events. Remarkably, not a single colony member was lost. While invitations were stereotypic in behaviour, termination was not. Analysis of speed revealed that the average transport speed was 4.2 cm s−1. Coupled adult-brood transport was slower than other transports but was more efficient than individual trips. Comparing tandem running with other popular recruitment methods in ants allows us to postulate that even though tandem running is primitive it is probably just another means to achieve the same end.

  13. Adjoint affine fusion and tadpoles

    Science.gov (United States)

    Urichuk, Andrew; Walton, Mark A.

    2016-06-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  14. Adjoint affine fusion and tadpoles

    CERN Document Server

    Urichuk, Andrew

    2016-01-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows, and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  15. JAERI tandem-accelerator and tandem-booster

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In 1982, aiming at the new development of atomic energy research, the tandem accelerator of Japan Atomic Energy Research Institute (JAERI) was installed. In fiscal year 1993, the superconducting boosters which can increase the ion energy by up to 4 times were added, and the research in the region below 1000 MeV became possible. Those are electrostatic type accelerators which are easy to be used especially in basic research field, and are useful for future research. The tandem accelerator has been operated while maintaining the first class performance as the accelerator for various kinds of heavy ion beam. It has the special shape among electrostatic type accelerators, and is excellent in the easiness of control and stability. The main particulars of the tandem accelerator are shown. As for the ion sources of the tandem accelerator, three cesium sputter type ion sources are installed on two high voltage stands. The kinds of the ions which can be accelerated are mainly negative ions. As the improvement, electron cyclotron resonance (ECR) ion sources are expected to be adopted. As for the tandem boosters, the 1/4 wavelength type resonance hollow cylinder was adopted. The constitution of the tandem boosters is explained. The way of utilizing the tandem accelerator system and the aim for hereafter are reported. (K.I.)

  16. Tandem Van de Graaff facility

    Data.gov (United States)

    Federal Laboratory Consortium — Completed in 1970, the Tandem Van de Graaff facility was for many years the world's largest electrostatic accelerator facility. It can provide researchers with beams...

  17. PCR-free digital minisatellite tandem repeat genotyping.

    Science.gov (United States)

    Chen, Yuchao; Seo, Tae Seok

    2011-06-01

    We demonstrated a proof-of-concept for novel minisatellite tandem repeat typing, called PCR-free digital VNTR (variable number tandem repeat) typing, which is composed of three steps: a ligation reaction instead of PCR thermal cycling, magnetic bead-based solid-phase capture for purification, and an elongated sample stacking microcapillary electrophoresis (μCE) for sensitive digital coding of repeat number. We designed a 16-bp fluorescently labeled ligation probe which is complementary to a repeat unit of a biotinylated synthetic template mimicking the human D1S80 VNTR locus and is randomly hybridized with the minisatellite tandem repeats. A quick isothermal ligation reaction was followed to link the adjacent ligation probes on the DNA templates, and then the ligated products were purified by streptavidin-coated magnetic beads. After a denaturing step, a large amount of ligated products whose size difference was equivalent to the repeat unit were released and recovered. Through the elongated sample stacking μCE separation on a microdevice, the fluorescence signal of the ligated products was generated in the electropherogram and the peak number was directly counted which was exactly matched with the repeat number of VNTR locus. We could successfully identify the minisatellite tandem repeat number with only 5 fmol of DNA template in 30 min.

  18. Realization of Fractal Affine Transformation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper gives the definition of fractal affine transformation and presents a specific method for its realization and its cor responding mathematical equations which are essential in fractal image construction.

  19. Affinity chromatography of phosphorylated proteins.

    Science.gov (United States)

    Tchaga, Grigoriy S

    2008-01-01

    This chapter covers the use of immobilized metal ion affinity chromatography (IMAC) for enrichment of phosphorylated proteins. Some requirements for successful enrichment of these types of proteins are discussed. An experimental protocol and a set of application data are included to enable the scientist to obtain high-yield results in a very short time with pre-packed phospho-specific metal ion affinity resin (PMAC).

  20. Oriented angles in affine space

    Directory of Open Access Journals (Sweden)

    Włodzimierz Waliszewski

    2004-05-01

    Full Text Available The concept of a smooth oriented angle in an arbitrary affine space is introduced. This concept is based on a kinematics concept of a run. Also, a concept of an oriented angle in such a space is considered. Next, it is shown that the adequacy of these concepts holds if and only if the affine space, in question, is of dimension 2 or 1.

  1. Video Screen Capture Basics

    Science.gov (United States)

    Dunbar, Laura

    2014-01-01

    This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.

  2. A Tandem Valve, a unique complication of TAVR

    Directory of Open Access Journals (Sweden)

    Srinivasan Sattiraju

    2016-02-01

    Full Text Available , MD1*,, MD1,, MD1,, MD2, MD2,, MD, PhD3 1. Division of Cardiology, Carle Heart and Vascular Institute, Carle Hospital, Urbana, IL 2. Cardiovascular Surgery, Carle Heart and Vascular Institute, Carle Hospital, Urbana, IL 3. Division of Cardiology, University of Minnesota Medical Center, Minneapolis, MN Received: 11-1-16, Reviewed: 22-1-16, Accepted: 26-1-16 Keywords: Transcatheter aortic valve replacement, TAVR, Valve embolisation DOI: ABSTRACT We report a unique complication of transcatheter aortic valve replacement (TAVR in which there is mechanical entrapment of two Edward Sapien valves. The tandem valve con guration created a high gradient across the valves stuck in tandem. The images and videos in this case capture ndings that underscore the complexity of interaction between two prosthetic valves. We believe this case serves a high teaching value for physicians taking care of patients with aortic stenosis managed with TAVR approach.

  3. Capture Their Attention: Capturing Lessons Using Screen Capture Software

    Science.gov (United States)

    Drumheller, Kristina; Lawler, Gregg

    2011-01-01

    When students miss classes for university activities such as athletic and academic events, they inevitably miss important class material. Students can get notes from their peers or visit professors to find out what they missed, but when students miss new and challenging material these steps are sometimes not enough. Screen capture and recording…

  4. Ligand binding by the tandem glycine riboswitch depends on aptamer dimerization but not double ligand occupancy.

    Science.gov (United States)

    Ruff, Karen M; Strobel, Scott A

    2014-11-01

    The glycine riboswitch predominantly exists as a tandem structure, with two adjacent, homologous ligand-binding domains (aptamers), followed by a single expression platform. The recent identification of a leader helix, the inclusion of which eliminates cooperativity between the aptamers, has reopened the debate over the purpose of the tandem structure of the glycine riboswitch. An equilibrium dialysis-based assay was combined with binding-site mutations to monitor glycine binding in each ligand-binding site independently to understand the role of each aptamer in glycine binding and riboswitch tertiary interactions. A series of mutations disrupting the dimer interface was used to probe how dimerization impacts ligand binding by the tandem glycine riboswitch. While the wild-type tandem riboswitch binds two glycine equivalents, one for each aptamer, both individual aptamers are capable of binding glycine when the other aptamer is unoccupied. Intriguingly, glycine binding by aptamer-1 is more sensitive to dimerization than glycine binding by aptamer-2 in the context of the tandem riboswitch. However, monomeric aptamer-2 shows dramatically weakened glycine-binding affinity. In addition, dimerization of the two aptamers in trans is dependent on glycine binding in at least one aptamer. We propose a revised model for tandem riboswitch function that is consistent with these results, wherein ligand binding in aptamer-1 is linked to aptamer dimerization and stabilizes the P1 stem of aptamer-2, which controls the expression platform.

  5. Conformational equilibria and intrinsic affinities define integrin activation.

    Science.gov (United States)

    Li, Jing; Su, Yang; Xia, Wei; Qin, Yan; Humphries, Martin J; Vestweber, Dietmar; Cabañas, Carlos; Lu, Chafen; Springer, Timothy A

    2017-03-01

    We show that the three conformational states of integrin α5β1 have discrete free energies and define activation by measuring intrinsic affinities for ligand of each state and the equilibria linking them. The 5,000-fold higher affinity of the extended-open state than the bent-closed and extended-closed states demonstrates profound regulation of affinity. Free energy requirements for activation are defined with protein fragments and intact α5β1 On the surface of K562 cells, α5β1 is 99.8% bent-closed. Stabilization of the bent conformation by integrin transmembrane and cytoplasmic domains must be overcome by cellular energy input to stabilize extension. Following extension, headpiece opening is energetically favored. N-glycans and leg domains in each subunit that connect the ligand-binding head to the membrane repel or crowd one another and regulate conformational equilibria in favor of headpiece opening. The results suggest new principles for regulating signaling in the large class of receptors built from extracellular domains in tandem with single-span transmembrane domains.

  6. Neutron Capture Nucleosynthesis

    CERN Document Server

    Kiss, Miklos

    2016-01-01

    Heavy elements (beyond iron) are formed in neutron capture nucleosynthesis processes. We have proposed a simple unified model to investigate the neutron capture nucleosynthesis in arbitrary neutron density environment. We have also investigated what neutron density is required to reproduce the measured abundance of nuclei assuming equilibrium processes. We found both of these that the medium neutron density has a particularly important role at neutron capture nucleosynthesis. About these results most of the nuclei can formed at medium neutron capture density environment e.g. in some kind of AGB stars. Besides these observations our model is capable to use educational purpose.

  7. Affine Contractions on the Plane

    Science.gov (United States)

    Celik, D.; Ozdemir, Y.; Ureyen, M.

    2007-01-01

    Contractions play a considerable role in the theory of fractals. However, it is not easy to find contractions which are not similitudes. In this study, it is shown by counter examples that an affine transformation of the plane carrying a given triangle onto another triangle may not be a contraction even if it contracts edges, heights or medians.…

  8. Asymmetric tandem organic solar cells

    Science.gov (United States)

    Howells, Thomas J.

    Organic photovoltaics (OPVs) is an area that has attracted much attention recently as a potential low cost, sustainable source of energy with a good potential for full-scale commercialisation. Understanding the factors that determine the efficiency of such cells is therefore a high priority, as well as developing ways to boost efficiency to commercially-useful levels. In addition to an intensive search for new materials, significant effort has been spent on ways to squeeze more performance out of existing materials, such as multijunction cells. This thesis investigates double junction tandem cells in the context of small molecule organic materials. . Two different organic electron donor materials, boron subphthalocyanine chloride (SubPc) and aluminium phthalocyanine chloride (ClAlPc) were used as donors in heterojunctions with C60 to create tandem cells for this thesis. These materials have been previously used for solar cells and the absorption spectra of the donor materials complement each other, making them good candidates for tandem cell architectures. The design of the recombination layer between the cells is considered first, with silver nanoparticles demonstrated to work well as recombination centres for charges from the front and back sub-cells, necessary to avoid a charge build-up at the interface. The growth conditions for the nanoparticles are optimised, with the tandem cells outperforming the single heterojunction architecture. Optical modelling is considered as a method to improve the understanding of thin film solar cells, where interference effects from the reflective aluminium electrode are important in determining the magnitude of absorption a cell can achieve. The use of such modelling is first demonstrated in hybrid solar cells based on a SubPc donor with a titanium oxide (TiOx) acceptor; this system is ideal for observing the effects of interference as only the SubPc layer has significant absorption. The modelling is then applied to tandem cells

  9. Capture ready study

    Energy Technology Data Exchange (ETDEWEB)

    Minchener, A.

    2007-07-15

    There are a large number of ways in which the capture of carbon as carbon dioxide (CO{sub 2}) can be integrated into fossil fuel power stations, most being applicable for both gas and coal feedstocks. To add to the choice of technology is the question of whether an existing plant should be retrofitted for capture, or whether it is more attractive to build totally new. This miscellany of choices adds considerably to the commercial risk of investing in a large power station. An intermediate stage between the non-capture and full capture state would be advantageous in helping to determine the best way forward and hence reduce those risks. In recent years the term 'carbon capture ready' or 'capture ready' has been coined to describe such an intermediate stage plant and is now widely used. However a detailed and all-encompassing definition of this term has never been published. All fossil fuel consuming plant produce a carbon dioxide gas byproduct. There is a possibility of scrubbing it with an appropriate CO{sub 2} solvent. Hence it could be said that all fossil fuel plant is in a condition for removal of its CO{sub 2} effluent and therefore already in a 'capture ready' state. Evidently, the practical reality of solvent scrubbing could cost more than the rewards offered by such as the ETS (European Trading Scheme). In which case, it can be said that although the possibility exists of capturing CO{sub 2}, it is not a commercially viable option and therefore the plant could not be described as ready for CO{sub 2} capture. The boundary between a capture ready and a non-capture ready condition using this definition cannot be determined in an objective and therefore universally acceptable way and criteria must be found which are less onerous and less potentially contentious to assess. 16 refs., 2 annexes.

  10. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health fol

  11. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  12. Theoretical proton affinity and fluoride affinity of nerve agent VX.

    Science.gov (United States)

    Bera, Narayan C; Maeda, Satoshi; Morokuma, Keiji; Viggiano, Al A

    2010-12-23

    Proton affinity and fluoride affinity of nerve agent VX at all of its possible sites were calculated at the RI-MP2/cc-pVTZ//B3LYP/6-31G* and RI-MP2/aug-cc-pVTZ//B3LYP/6-31+G* levels, respectively. The protonation leads to various unique structures, with H(+) attached to oxygen, nitrogen, and sulfur atoms; among which the nitrogen site possesses the highest proton affinity of -ΔE ∼ 251 kcal/mol, suggesting that this is likely to be the major product. In addition some H(2), CH(4) dissociation as well as destruction channels have been found, among which the CH(4) + [Et-O-P(═O)(Me)-S-(CH(2))(2)-N(+)(iPr)═CHMe] product and the destruction product forming Et-O-P(═O)(Me)-SMe + CH(2)═N(+)(iPr)(2) are only 9 kcal/mol less stable than the most stable N-protonated product. For fluoridization, the S-P destruction channel to give Et-O-P(═O)(Me)(F) + [S-(CH(2))(2)-N-(iPr)(2)](-) is energetically the most favorable, with a fluoride affinity of -ΔE ∼ 44 kcal. Various F(-) ion-molecule complexes are also found, with the one having F(-) interacting with two hydrogen atoms in different alkyl groups to be only 9 kcal/mol higher than the above destruction product. These results suggest VX behaves quite differently from surrogate systems.

  13. Electron affinity of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Babcock, L.M.; Pentecost, T.; Koppenol, W.H. (Louisiana State Univ., Baton Rouge (USA))

    1989-12-14

    The flowing afterglow technique was used to determine the electron affinity of chlorine dioxide. A value of 2.37 {plus minus} 0.10 eV was found by bracketing between the electron affinities of HS* and SF{sub 4} as a lower limit and that of NO{sub 2} as an upper limit. This value is in excellent agreement with 2.32 eV predicted from a simple thermodynamic cycle involving the reduction potential of the ClO{sub 2}/ClO{sub 2}{sup {minus}} couple and a Gibbs hydration energy identical with that of SO{sub 2}{sup {sm bullet}{minus}}.

  14. Affine density in wavelet analysis

    CERN Document Server

    Kutyniok, Gitta

    2007-01-01

    In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.

  15. Lectin affinity chromatography of glycolipids

    Energy Technology Data Exchange (ETDEWEB)

    Torres, B.V.; Smith, D.F.

    1987-05-01

    Since glycolipids (GLs) are either insoluble or form mixed micelles in water, lectin affinity chromatography in aqueous systems has not been applied to their separation. They have overcome this problem by using tetrahydrofuran (THF) in the mobile phase during chromatography. Affinity columns prepared with the GalNAc-specific Helix pomatia agglutinin (HPA) and equilibrated in THF specifically bind the (/sup 3/H)oligosaccharide derived from Forssman GL indicating that the immobilized HPA retained its carbohydrate-binding specificity in this solvent. Intact Forssman GL was bound by the HPA-column equilibrated in THF and was specifically eluted with 0.1 mg/ml GalNAc in THF. Purification of the Forssman GL was achieved when a crude lipid extract of sheep erythrocyte membranes was applied to the HPA-column in THF. Non-specifically bound GLs were eluted from the column using a step gradient of aqueous buffer in THF, while the addition of GalNAc was required to elute the specifically bound GLs. Using this procedure the A-active GLs were purified from a crude lipid extract of type A human erythrocytes in a single chromatographic step. The use of solvents that maintain carbohydrate-binding specificity and lipid solubility will permit the application of affinity chromatography on immobilized carbohydrate-binding proteins to intact GLs.

  16. Nanocrystal assembly for tandem catalysis

    Science.gov (United States)

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

    2014-10-14

    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  17. Determination of the Astrophysical S(E) Factors or Rates for Radiative Capture Reaction with One Nucleon Transfer Reaction%Determination of the Astrophysical S(E) Factors or Rates for Radiative Capture Reaction with One Nucleon Transfer Reaction

    Institute of Scientific and Technical Information of China (English)

    李志宏; 郭冰; 李云居; 苏俊; 李二涛; 白希祥; 王友宝; 曾晟; 王宝祥; 颜胜权; 李志常; 刘建成; 连钢; 金孙均; 刘鑫; 柳卫平

    2012-01-01

    The radiative capture reaction plays an important role in nuclear astrophysics. We have indirectly measured the astrophysical S(E) factors for some proton capture reactions and reaction rates for several neutron capture reactions with one nucleon transfer reactions at HI-13 tandem accelerator in recent years. Some of them are compiled into IAEA EXFOR database and JINA REACLIB project, and used in the network calculations of Big Bang nucleosynthesis and type-I X-ray bursts.

  18. Nanocrystal bilayer for tandem catalysis.

    Science.gov (United States)

    Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu; Huo, Ziyang; Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Somorjai, Gabor A; Yang, Peidong

    2011-05-01

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO(2)-Pt and Pt-SiO(2), can be used to catalyse two distinct sequential reactions. The CeO(2)-Pt interface catalysed methanol decomposition to produce CO and H(2), which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO(2) interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts.

  19. "Nanocrystal bilayer for tandem catalysis"

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  20. The Quasi—affine Maps and Fractals

    Institute of Scientific and Technical Information of China (English)

    LunhaiLONG; GangCHEN

    1997-01-01

    In this paper,we discuss the discretization of the affine maps in R2,that is ,we consider a class of maps in Z2,which are induced by affine maps and called the quasi-affine maps.We investigate the properties and the dynamical behaviour of such maps,and give a sort of construction of complicated fractals by using quasi-affine maps.

  1. Affine connections on involutive G-structures

    OpenAIRE

    Merkulov, Sergey A.

    1995-01-01

    This paper is a review of the twistor theory of irreducible G-structures and affine connections. Long ago, Berger presented a very restricted list of possible irreducibly acting holonomies of torsion-free affine connections. His list was complete in the part of metric connections, while the situation with holonomies of non-metric torsion-free affine connections was and remains rather unclear. One of the results discussed in this review asserts that any torsion-free holomorphic affine connecti...

  2. Marine turtle capture data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To estimate abundance, growth, and survival rate and to collect tissue samples, marine turtles are captured at nesting beaches and foraging grounds through various...

  3. Manifolds with integrable affine shape operator

    Directory of Open Access Journals (Sweden)

    Daniel A. Joaquín

    2005-05-01

    Full Text Available This work establishes the conditions for the existence of vector fields with the property that theirs covariant derivative, with respect to the affine normal connection, be the affine shape operatorS in hypersurfaces. Some results are obtained from this property and, in particular, for some kind of affine decomposable hypersurfaces we explicitely get the actual vector fields.

  4. A protein expression system for tandem affinity purification in Xanthomonas citri subsp. citri

    Directory of Open Access Journals (Sweden)

    Giordanni C. Dantas

    2016-06-01

    Full Text Available Abstract Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp. citri (Xac, is one of the most devastating diseases to affect citrus crops. There is no treatment for citrus canker; effective control against the spread of Xac is usually achieved by the elimination of affected plants along with that of asymptomatic neighbors. An in depth understanding of the pathogen is the keystone for understanding of the disease; to this effect we are committed to the development of strategies to ease the study of Xac. Genome sequencing and annotation of Xac revealed that ∼37% of the genome is composed of hypothetical ORFs. To start a systematic characterization of novel factors encoded by Xac, we constructed integrative-vectors for protein expression specific to this bacterium. The vectors allow for the production of TAP-tagged proteins in Xac under the regulation of the xylose promoter. In this study, we show that a TAP-expression vector, integrated into the amy locus of Xac, does not compromise its virulence. Furthermore, our results also demonstrate that the polypeptide TAP can be overproduced in Xac and purified from the soluble phase of cell extracts. Our results substantiate the use of our vectors for protein expression in Xac thus contributing a novel tool for the characterization of proteins and protein complexes generated by this bacterium in vivo.

  5. Purification of Components of the Translation Elongation Factor Complex of Plasmodium falciparum by Tandem Affinity Purification▿

    OpenAIRE

    2007-01-01

    Plasmodium falciparum is the causative agent of severe human malaria, responsible for over 2 million deaths annually. Of the 5,300 polypeptides predicted to control the parasite life cycle in mosquitoes and humans, 60% are of unknown function. A major challenge of malaria postgenomic biology is to understand how the 5,300 predicted proteins coexist and interact to perform the essential tasks that define the complex life cycle of the parasite. One approach to assign function to these proteins ...

  6. Multiparameter cell affinity chromatography: separation and analysis in a single microfluidic channel.

    Science.gov (United States)

    Li, Peng; Gao, Yan; Pappas, Dimitri

    2012-10-02

    The ability to sort and capture more than one cell type from a complex sample will enable a wide variety of studies of cell proliferation and death and the analysis of disease states. In this work, we integrated a pneumatic actuated control layer to an affinity separation layer to create different antibody-coating regions on the same fluidic channel. The comparison of different antibody capture capabilities to the same cell line was demonstrated by flowing Ramos cells through anti-CD19- and anti-CD71-coated regions in the same channel. It was determined that the cell capture density on the anti-CD19 region was 2.44 ± 0.13 times higher than that on the anti-CD71-coated region. This approach can be used to test different affinity molecules for selectivity and capture efficiency using a single cell line in one separation. Selective capture of Ramos and HuT 78 cells from a mixture was also demonstrated using two antibody regions in the same channel. Greater than 90% purity was obtained on both capture areas in both continuous flow and stop flow separation modes. A four-region antibody-coated device was then fabricated to study the simultaneous, serial capture of three different cell lines. In this case the device showed effective capture of cells in a single separation channel, opening up the possibility of multiple cell sorting. Multiparameter sequential blood sample analysis was also demonstrated with high capture specificity (>97% for both CD19+ and CD4+ leukocytes). The chip can also be used to selectively treat cells after affinity separation.

  7. Short Tandem Repeat DNA Internet Database

    Science.gov (United States)

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  8. Fluorous-assisted metal chelate affinity extraction technique for analysis of protein kinase activity.

    Science.gov (United States)

    Hayama, Tadashi; Kiyokawa, Ena; Yoshida, Hideyuki; Imakyure, Osamu; Yamaguchi, Masatoshi; Nohta, Hitoshi

    2016-08-15

    We have developed a fluorous affinity-based extraction method for measurement of protein kinase activity. In this method, a fluorescent peptide substrate was phosphorylated by a protein kinase, and the obtained phosphopeptide was selectively captured with Fe(III)-immobilized perfluoroalkyliminodiacetic acid reagent via a metal chelate affinity technique. Next, the captured phosphopeptide was selectively extracted into a fluorous solvent mixture, tetradecafluorohexane and 1H,1H,2H,2H-tridecafluoro-1-n-octanol (3:1, v/v), using the specificity of fluorous affinity (fluorophilicity). In contrast, the remained substrate peptide in the aqueous (non-fluorous) phase was easily measured fluorimetrically. Finally, the enzyme activity could be assayed by measuring the decrease in fluorescence. The feasibility of this method was demonstrated by applying the method for measurement of the activity of cAMP-dependent protein kinase (PKA) using its substrate peptide (kemptide) pre-labeled with carboxytetramethylrhodamine (TAMRA).

  9. Topological conjugacy classes of affine maps

    OpenAIRE

    2008-01-01

    A map $f: \\ff^n \\to \\ff^n$ over a field $\\ff$ is called affine if it is of the form $f(x)=Ax+b$, where the matrix $A \\in \\ff^{n\\times n}$ is called the linear part of affine map and $b \\in \\ff^n$. The affine maps over $\\ff=\\rr$ or $\\cc$ are investigated. We prove that affine maps having fixed points are topologically conjugate if and only if their linear parts are topologically conjugate. If affine maps have no fixed points and $n=1$ or 2, then they are topologically conjugate if and only if ...

  10. Using Affinity Diagrams to Evaluate Interactive Prototypes

    DEFF Research Database (Denmark)

    Lucero, Andrés

    2015-01-01

    Affinity diagramming is a technique used to externalize, make sense of, and organize large amounts of unstructured, far-ranging, and seemingly dissimilar qualitative data. HCI and interaction design practitioners have adopted and used affinity diagrams for different purposes. This paper discusses...... our particular use of affinity diagramming in prototype evaluations. We reflect on a decade’s experience using affinity diagramming across a number of projects, both in industry and academia. Our affinity diagramming process in interaction design has been tailored and consists of four stages: creating...

  11. Muon capture at PSI

    CERN Document Server

    Winter, Peter

    2010-01-01

    Measuring the rate of muon capture in hydrogen provides one of the most direct ways to study the axial current of the nucleon. The MuCap experiment uses a negative muon beam stopped in a time projection chamber operated with ultra-pure hydrogen gas. Surrounded by a decay electron detector, the lifetime of muons in hydrogen can be measured to determine the singlet capture rate Lambda_s to a final precision of 1%. The capture rate determines the nucleon's pseudoscalar form factor g_p. A first result, g_p = 7.3 +- 1.1, has been published and the final analysis of the full statistics will reduce the error by a factor of up to 3. Muon capture on the deuteron probes the weak axial current in the two-nucleon system. Within the framework of effective field theories the calculation of such two-nucleon processes involving the axial current requires the knowledge of one additional low energy constant which can be extracted from the doublet capture rate Lambda_d. The same constant then allows to model-independently calcu...

  12. Tandem mirror technology demonstration facility

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M/sup 2/) on an 8-m/sup 2/ test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m/sup 2/ and give the necessary experience for successful operation of an ETR.

  13. Performance of a new protein A affinity membrane for the primary recovery of antibodies.

    Science.gov (United States)

    Boi, Cristiana; Dimartino, Simone; Sarti, Giulio C

    2008-01-01

    Recovery of antibodies with Protein A affinity chromatography columns has become the standard for the biotechnology industry. Membrane affinity chromatography has not yet experienced extensive application due to the lower capacity of membrane supports compared to chromatographic beads. In this work, new affinity membranes endowed with an interesting binding capacity for human IgG are studied in view of their application in the capturing step of a monoclonal antibody production process. The membranes have been extensively tested with pure IgG solutions and with a cell culture supernatant containing IgG1. The effects of feed flow rate and IgG concentration on the separation performances have been studied in detail, considering in particular binding capacity, selectivity and recovery. These new high capacity affinity membranes appear good candidates to avoid the throughput limitations and other well-known drawbacks of traditional bead-based chromatographic columns.

  14. Muon capture in deuterium

    Science.gov (United States)

    Ricci, P.; Truhlík, E.; Mosconi, B.; Smejkal, J.

    2010-06-01

    Model dependence of the capture rates of the negative muon capture in deuterium is studied starting from potential models and the weak two-body meson exchange currents constructed in the tree approximation and also from an effective field theory. The tree one-boson exchange currents are derived from the hard pion chiral Lagrangians of the NΔπρωa system. If constructed in conjunction with the one-boson exchange potentials, the capture rates can be calculated consistently. On the other hand, the effective field theory currents, constructed within the heavy baryon chiral perturbation theory, contain a low energy constant d that cannot be extracted from data at the one-particle level nor determined from the first principles. Comparative analysis of the results for the doublet transition rate allows us to extract the constant d.

  15. Quantitative proteome analysis using isotope-coded affinity tags and mass spectrometry.

    Science.gov (United States)

    Shiio, Yuzuru; Aebersold, Ruedi

    2006-01-01

    A main objective of proteomics research is to systematically identify and quantify proteins in a given proteome (cells, subcellular fractions, protein complexes, tissues or body fluids). Protein labeling with isotope-coded affinity tags (ICAT) followed by tandem mass spectrometry allows sequence identification and accurate quantification of proteins in complex mixtures, and has been applied to the analysis of global protein expression changes, protein changes in subcellular fractions, components of protein complexes, protein secretion and body fluids. This protocol describes protein-sample labeling with ICAT reagents, chromatographic fractionation of the ICAT-labeled tryptic peptides, and protein identification and quantification using tandem mass spectrometry. The method is suitable for both large-scale analysis of complex samples including whole proteomes and small-scale analysis of subproteomes, and allows quantitative analysis of proteins, including those that are difficult to analyze by gel-based proteomics technology.

  16. US Spacesuit Knowledge Capture

    Science.gov (United States)

    Chullen, Cinda; Thomas, Ken; McMann, Joe; Dolan, Kristi; Bitterly, Rose; Lewis, Cathleen

    2011-01-01

    The ability to learn from both the mistakes and successes of the past is vital to assuring success in the future. Due to the close physical interaction between spacesuit systems and human beings as users, spacesuit technology and usage lends itself rather uniquely to the benefits realized from the skillful organization of historical information; its dissemination; the collection and identification of artifacts; and the education of those in the field. The National Aeronautics and Space Administration (NASA), other organizations and individuals have been performing United States (U.S.) Spacesuit Knowledge Capture since the beginning of space exploration. Avenues used to capture the knowledge have included publication of reports; conference presentations; specialized seminars; and classes usually given by veterans in the field. More recently the effort has been more concentrated and formalized whereby a new avenue of spacesuit knowledge capture has been added to the archives in which videotaping occurs engaging both current and retired specialists in the field presenting technical scope specifically for education and preservation of knowledge. With video archiving, all these avenues of learning can now be brought to life with the real experts presenting their wealth of knowledge on screen for future learners to enjoy. Scope and topics of U.S. spacesuit knowledge capture have included lessons learned in spacesuit technology, experience from the Gemini, Apollo, Skylab and Shuttle programs, hardware certification, design, development and other program components, spacesuit evolution and experience, failure analysis and resolution, and aspects of program management. Concurrently, U.S. spacesuit knowledge capture activities have progressed to a level where NASA, the National Air and Space Museum (NASM), Hamilton Sundstrand (HS) and the spacesuit community are now working together to provide a comprehensive closed-looped spacesuit knowledge capture system which includes

  17. Detecting long tandem duplications in genomic sequences

    Directory of Open Access Journals (Sweden)

    Audemard Eric

    2012-05-01

    Full Text Available Abstract Background Detecting duplication segments within completely sequenced genomes provides valuable information to address genome evolution and in particular the important question of the emergence of novel functions. The usual approach to gene duplication detection, based on all-pairs protein gene comparisons, provides only a restricted view of duplication. Results In this paper, we introduce ReD Tandem, a software using a flow based chaining algorithm targeted at detecting tandem duplication arrays of moderate to longer length regions, with possibly locally weak similarities, directly at the DNA level. On the A. thaliana genome, using a reference set of tandem duplicated genes built using TAIR,a we show that ReD Tandem is able to predict a large fraction of recently duplicated genes (dS  Conclusions ReD Tandem allows to identify large tandem duplications without any annotation, leading to agnostic identification of tandem duplications. This approach nicely complements the usual protein gene based which ignores duplications involving non coding regions. It is however inherently restricted to relatively recent duplications. By recovering otherwise ignored events, ReD Tandem gives a more comprehensive view of existing evolutionary processes and may also allow to improve existing annotations.

  18. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  19. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    Mandjes, M.R.H.

    2004-01-01

    We examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution of the total

  20. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    M.R.H. Mandjes

    2004-01-01

    Abstract : We examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution o

  1. Neutron capture therapies

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

    1999-01-01

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  2. Neutron capture therapies

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, J.C.; Shefer, R.E.; Klinkowstein, R.E.

    1999-11-02

    In one embodiment there is provided an application of the {sup 10}B(n,{alpha}){sup 7}Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  3. Tandem Catalysis Utilizing Olefin Metathesis Reactions.

    Science.gov (United States)

    Zieliński, Grzegorz K; Grela, Karol

    2016-07-01

    Since olefin metathesis transformation has become a favored synthetic tool in organic synthesis, more and more distinct non-metathetical reactions of alkylidene ruthenium complexes have been developed. Depending on the conditions applied, the same olefin metathesis catalysts can efficiently promote isomerization reactions, hydrogenation of C=C double bonds, oxidation reactions, and many others. Importantly, these transformations can be carried out in tandem with olefin metathesis reactions. Through addition of one portion of a catalyst, a tandem process provides structurally advanced products from relatively simple substrates without the need for isolation of the intermediates. These aspects not only make tandem catalysis very attractive from a practical point of view, but also open new avenues in (retro)synthetic planning. However, in the literature, the term "tandem process" is sometimes used improperly to describe other types of multi-reaction sequences. In this Concept, a number of examples of tandem catalysis involving olefin metathesis are discussed with an emphasis on their synthetic value.

  4. CAPTURED End Evaluation Synthesis Report

    NARCIS (Netherlands)

    Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the Synthesis Study of the CAPTURED Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the three CAPTURED partners have achieved commendable results. Ten lessons learned are formulated th

  5. Capturing RNA-dependent pathways for cryo-EM analysis

    Directory of Open Access Journals (Sweden)

    Deborah F Kelly

    2012-04-01

    Full Text Available Cryo-Electron Microscopy (EM is a powerful technique to visualize biological processes at nanometer resolution. Structural studies of macromolecular assemblies are typically performed on individual complexes that are biochemically isolated from their cellular context. Here we present a molecular imaging platform to capture and view multiple components of cellular pathways within a functionally relevant framework. We utilized the bacterial protein synthesis machinery as a model system to develop our approach. By using modified Affinity Grid surfaces, we were able to recruit multiple protein assemblies bound to nascent strands of mRNA. The combined use of Affinity Capture technology and single particle electron microscopy provide the basis for visualizing RNA-dependent pathways in a remarkable new way.

  6. Ordinary differential equations in affine geometry

    Directory of Open Access Journals (Sweden)

    Salvador Gigena

    1996-05-01

    Full Text Available The method of qualitative analysis is used, as applied to a class of fourth order, nonlinear ordinary differential equations, in order to classify, both locally and globally, two classes of hypersurfaces of decomposable type in affine geometry: those with constant unimodular affine mean curvature L , and those with constant Riemannian scalar curvature R. This allows to provide a large number of new examples of hypersurfaces in affine geometry.

  7. Ordinary differential equations in affine geometry

    OpenAIRE

    Salvador Gigena

    1996-01-01

    The method of qualitative analysis is used, as applied to a class of fourth order, nonlinear ordinary differential equations, in order to classify, both locally and globally, two classes of hypersurfaces of decomposable type in affine geometry: those with constant unimodular affine mean curvature L , and those with constant Riemannian scalar curvature R. This allows to provide a large number of new examples of hypersurfaces in affine geometry.

  8. Multipole solutions in metric-affine gravity

    CERN Document Server

    Socorro, J; Macías, A; Mielke, E W; Socorro, José; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.

    1998-01-01

    Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. Here, by using the harmonic map ansatz, a new class of multipole like solutions in the metric affine gravity theory (MAG) is obtained.

  9. Measurement of the electron affinity of lanthanum

    Energy Technology Data Exchange (ETDEWEB)

    Covington, A.M.; Calabrese, D.; Thompson, J.S. [Department of Physics and Chemical Physics Programme, University of Nevada, Reno, NV 89557-0058 (United States); Kvale, T.J. [Department of Physics and Astronomy, University of Toledo, OH 43606-3390 (United States)

    1998-10-28

    The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first electron affinity measurement for lanthanum and one of the first measurements of an electron affinity of a rare-earth series element. The electron affinity of lanthanum was measured to be 0.47{+-}0.02 eV. At least one bound excited state of La{sup -} was also observed in the photoelectron spectra, and the binding energy relative to the ground state of lanthanum was measured as 0.17{+-}0.02 eV. The present experimental measurements are compared to a recent calculation. (author). Letter-to-the-editor.

  10. Affine connections, midpoint formation, and point reflection

    DEFF Research Database (Denmark)

    Kock, Anders

    2011-01-01

    We describe some differential-geometric structures in combinatorial terms: namely affine connections and their torsion and curvature, and we show that torsion free affine connections may equivalently be presented in terms of some simpler combinatorial structure: midpoint formation, and point refl...... reflection (geodesic symmetry). The method employed is that of synthetic differential geometry, which is briefly explained.......We describe some differential-geometric structures in combinatorial terms: namely affine connections and their torsion and curvature, and we show that torsion free affine connections may equivalently be presented in terms of some simpler combinatorial structure: midpoint formation, and point...

  11. Status of JAERI tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi; Kanda, Susumu; Takeuchi, Suehiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] (and others)

    2001-02-01

    JAERI Tandem Accelerator had been operated approximately 230 days in fiscal year of 1999. Meanwhile, we had three times of maintenance period with vent. Total operation-times were 5273 hours. We could not carry out the experiment using rare gas, due to malfunction of the RF power supply for the ECR ion source. The type of the RF power supply is peculiar and it is impossible to get spare parts for repair. We are now investigating the backup RF power supply. The power supply for the magnet became unstable due to degradation of insulation in the shunt resistance, which is used for feedback stabilization. Stability was recovered after cleaning. The acrylic resin shaft was cracked. This cracks have a potential for severe accidents. So far bearing of the shaft has no problem. The reason of cracks may be self-destruction by charge accumulation in the shaft. JAERI Tandem Accelerator is approximately 20 years old. There appear requirements on the higher ion currents for additional ion species. Therefore, authors are investigating cost effective improvement plans of RFQ (Radio Frequency Quadra-pole) and IH type accelerator based on KEK (High Energy Accelerator Research Organization) R and D. As a whole, maintenance services for the control system are increasing due to some changes of computer programs. There are some difficulties to keep skilled personnel for facilities operation. Authors are gradually increasing hired personnel with contract from 1993. However, loads for JAERI permanent staffs are still heavy. It takes much longer time to educate skilled persons especially for safety. (Y. Tanaka)

  12. Supernova electron capture rates

    CERN Document Server

    Martínez-Pinedo, G

    1999-01-01

    We have calculated the Gamow-Teller strength distributions for the ground states and low lying states of several nuclei that play an important role in the precollapse evolution of supernova. The calculations reproduce the experimental GT distributions nicely. The GT distribution are used to calculate electron capture rates for typical presupernova conditions. The computed rates are noticeably smaller than the presently adopted rates. The possible implications for the supernova evolution are discussed.

  13. Structure of classical affine and classical affine fractional W-algebras

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)

    2015-01-15

    We introduce a classical BRST complex (See Definition 3.2.) and show that one can construct a classical affine W-algebra via the complex. This definition clarifies that classical affine W-algebras can be considered as quasi-classical limits of quantum affine W-algebras. We also give a definition of a classical affine fractional W-algebra as a Poisson vertex algebra. As in the classical affine case, a classical affine fractional W-algebra has two compatible λ-brackets and is isomorphic to an algebra of differential polynomials as a differential algebra. When a classical affine fractional W-algebra is associated to a minimal nilpotent, we describe explicit forms of free generators and compute λ-brackets between them. Provided some assumptions on a classical affine fractional W-algebra, we find an infinite sequence of integrable systems related to the algebra, using the generalized Drinfel’d and Sokolov reduction.

  14. In vitro evolution and affinity-maturation with Coliphage qβ display.

    Directory of Open Access Journals (Sweden)

    Claudia Skamel

    Full Text Available The Escherichia coli bacteriophage, Qβ (Coliphage Qβ, offers a favorable alternative to M13 for in vitro evolution of displayed peptides and proteins due to high mutagenesis rates in Qβ RNA replication that better simulate the affinity maturation processes of the immune response. We describe a benchtop in vitro evolution system using Qβ display of the VP1 G-H loop peptide of foot-and-mouth disease virus (FMDV. DNA encoding the G-H loop was fused to the A1 minor coat protein of Qβ resulting in a replication-competent hybrid phage that efficiently displayed the FMDV peptide. The surface-localized FMDV VP1 G-H loop cross-reacted with the anti-FMDV monoclonal antibody (mAb SD6 and was found to decorate the corners of the Qβ icosahedral shell by electron microscopy. Evolution of Qβ-displayed peptides, starting from fully degenerate coding sequences corresponding to the immunodominant region of VP1, allowed rapid in vitro affinity maturation to SD6 mAb. Qβ selected under evolutionary pressure revealed a non-canonical, but essential epitope for mAb SD6 recognition consisting of an Arg-Gly tandem pair. Finally, the selected hybrid phages induced polyclonal antibodies in guinea pigs with good affinity to both FMDV and hybrid Qβ-G-H loop, validating the requirement of the tandem pair epitope. Qβ-display emerges as a novel framework for rapid in vitro evolution with affinity-maturation to molecular targets.

  15. Global affine differential geometry of hypersurfaces

    CERN Document Server

    Li, An-Min; Zhao, Guosong; Hu, Zejun

    2015-01-01

    This book draws a colorful and widespread picture of global affine hypersurface theory up to the most recent state. Moreover, the recent development revealed that affine differential geometry- as differential geometry in general- has an exciting intersection area with other fields of interest, like partial differential equations, global analysis, convex geometry and Riemann surfaces.

  16. Dyes with high affinity for polylactide

    Institute of Scientific and Technical Information of China (English)

    Liang He; Shu Fen Zhang; Bing Tao Tang; Li Li Wang; Jin Zong Yang

    2007-01-01

    Attempts were made to develop dyes with high affinity for polylactide as an alternative to the existent commercial disperse dyes.The dyes synthesized according to the affinity concept of dye to polylactide exhibited excellent dyeing properties on polylactide compared with the commercial disperse dyes.

  17. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...

  18. Porosity of Self-affine Sets

    Institute of Scientific and Technical Information of China (English)

    Lifeng XI

    2008-01-01

    In this paper,it is proved that any self-affine set satisfying the strong separation condition is uniformly porous.The author constructs a self-affine set which is not porous,although the open set condition holds.Besides,the author also gives a C1 iterated function system such that its invariant set is not porous.

  19. On affine non-negative matrix factorization

    DEFF Research Database (Denmark)

    Laurberg, Hans; Hansen, Lars Kai

    2007-01-01

    We generalize the non-negative matrix factorization (NMF) generative model to incorporate an explicit offset. Multiplicative estimation algorithms are provided for the resulting sparse affine NMF model. We show that the affine model has improved uniqueness properties and leads to more accurate...

  20. Affine processes on positive semidefinite matrices

    CERN Document Server

    Cuchiero, Christa; Mayerhofer, Eberhard; Teichmann, Josef

    2009-01-01

    This paper provides the mathematical foundation for stochastically continuous affine processes on the cone of positive semidefinite symmetric matrices. These matrix-valued affine processes have arisen from a large and growing range of useful applications in finance, including multi-asset option pricing with stochastic volatility and correlation structures, and fixed-income models with stochastically correlated risk factors and default intensities.

  1. Capturing the Future: Direct and Indirect Probes of Neutron Capture

    Energy Technology Data Exchange (ETDEWEB)

    Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    This report documents aspects of direct and indirect neutron capture. The importance of neutron capture rates and methods to determine them are presented. The following conclusions are drawn: direct neutron capture measurements remain a backbone of experimental study; work is being done to take increased advantage of indirect methods for neutron capture; both instrumentation and facilities are making new measurements possible; more work is needed on the nuclear theory side to understand what is needed furthest from stability.

  2. Reflectable bases for affine reflection systems

    CERN Document Server

    Azam, Saeid; Yousofzadeh, Malihe

    2011-01-01

    The notion of a "root base" together with its geometry plays a crucial role in the theory of finite and affine Lie theory. However, it is known that such a notion does not exist for the recent generalizations of finite and affine root systems such as extended affine root systems and affine reflection systems. As an alternative, we introduce the notion of a "reflectable base", a minimal subset $\\Pi$ of roots such that the non-isotropic part of the root system can be recovered by reflecting roots of $\\Pi$ relative to the hyperplanes determined by $\\Pi$. We give a full characterization of reflectable bases for tame irreducible affine reflection systems of reduced types, excluding types $E_{6,7,8}$. As a byproduct of our results, we show that if the root system under consideration is locally finite then any reflectable base is an integral base.

  3. Improving image segmentation by learning region affinities

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  4. The Monitoring and Affinity Purification of Proteins Using Dual-Tags with Tetracysteine Motifs

    Energy Technology Data Exchange (ETDEWEB)

    Giannone, Richard J [ORNL; Liu, Yie [ORNL; Wang, Yisong [ORNL

    2009-01-01

    Identification and characterization of protein-protein interaction networks is essential for the elucidation of biochemical mechanisms and cellular function. Affinity purification in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as a very powerful tactic for the identification of specific protein-protein interactions. In this chapter we describe a comprehensive methodology that utilizes our recently developed dual-tag affinity purification system for the enrichment and identification of mammalian protein complexes. The protocol covers a series of separate but sequentially related techniques focused on the facile monitoring and purification of a dual-tagged protein of interest and its interacting partners via a system built with tetracysteine motifs and various combinations of affinity tags. Using human telomeric repeat binding factor 2 (TRF2) as an example, we have demonstrated the power of the system in terms of bait protein recovery after dual-tag affinity purification, detection of bait protein subcellular localization and expression, and successful identification of known and potentially novel TRF2 interacting proteins. Although the protocol described here has been optimized for the identification and characterization of TRF2-associated proteins, it is, in principle, applicable to the study of any other mammalian protein complexes that may be of interest to the research community.

  5. The Monitoring and Affinity Purification of Proteins Using Dual Tags with Tetracysteine Motifs

    Science.gov (United States)

    Giannone, Richard J.; Liu, Yie; Wang, Yisong

    Identification and characterization of protein-protein interaction networks is essential for the elucidation of biochemical mechanisms and cellular function. Affinity purification in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as a very powerful tactic for the identification of specific protein-protein interactions. In this chapter, we describe a comprehensive methodology that uses our recently developed dual-tag affinity purification system for the enrichment and identification of mammalian protein complexes. The protocol covers a series of separate but sequentially related techniques focused on the facile monitoring and purification of a dual-tagged protein of interest and its interacting partners via a system built with tetracysteine motifs and various combinations of affinity tags. Using human telomeric repeat binding factor 2 (TRF2) as an example, we demonstrate the power of the system in terms of bait protein recovery after dual-tag affinity purification, detection of bait protein subcellular localization and expression, and successful identification of known and potentially novel TRF2 interacting proteins. Although the protocol described here has been optimized for the identification and characterization of TRF2-associated proteins, it is, in principle, applicable to the study of any other mammalian protein complexes that may be of interest to the research community.

  6. Engineering an antibody with picomolar affinity to DOTA chelates of multiple radionuclides for pretargeted radioimmunotherapy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orcutt, Kelly Davis; Slusarczyk, Adrian L. [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Cieslewicz, Maryelise [Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ruiz-Yi, Benjamin [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bhushan, Kumar R. [Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Frangioni, John V. [Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Wittrup, K. Dane, E-mail: wittrup@mit.ed [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2011-02-15

    Introduction: In pretargeted radioimmunotherapy (PRIT), a bifunctional antibody is administered and allowed to pre-localize to tumor cells. Subsequently, a chelated radionuclide is administered and captured by cell-bound antibody while unbound hapten clears rapidly from the body. We aim to engineer high-affinity binders to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelates for use in PRIT applications. Methods: We mathematically modeled antibody and hapten pharmacokinetics to analyze hapten tumor retention as a function of hapten binding affinity. Motivated by model predictions, we used directed evolution and yeast surface display to affinity mature the 2D12.5 antibody to DOTA, reformatted as a single chain variable fragment (scFv). Results: Modeling predicts that for high antigen density and saturating bsAb dose, a hapten-binding affinity of 100 pM is needed for near-maximal hapten retention. We affinity matured 2D12.5 with an initial binding constant of about 10 nM to DOTA-yttrium chelates. Affinity maturation resulted in a 1000-fold affinity improvement to biotinylated DOTA-yttrium, yielding an 8.2{+-}1.9 picomolar binder. The high-affinity scFv binds DOTA complexes of lutetium and gadolinium with similar picomolar affinity and indium chelates with low nanomolar affinity. When engineered into a bispecific antibody construct targeting carcinoembryonic antigen, pretargeted high-affinity scFv results in significantly higher tumor retention of a {sup 111}In-DOTA hapten compared to pretargeted wild-type scFv in a xenograft mouse model. Conclusions: We have engineered a versatile, high-affinity, DOTA-chelate-binding scFv. We anticipate it will prove useful in developing pretargeted imaging and therapy protocols to exploit the potential of a variety of radiometals.

  7. Inverted 3J Tandem Thermophotovoltaic Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Semiconductor proposes to make an InGaAs-based three-junction (3J) tandem thermophotovoltaic (TPV) cell to utilize more of the blackbody spectrum (from a GPHS)...

  8. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....

  9. Non-Zenoness of piecewise affine dynamical systems and affine complementarity systems with inputs

    Institute of Scientific and Technical Information of China (English)

    Le Quang THUAN

    2014-01-01

    In the context of continuous piecewise affine dynamical systems and affine complementarity systems with inputs, we study the existence of Zeno behavior, i.e., infinite number of mode transitions in a finite-length time interval, in this paper. The main result reveals that continuous piecewise affine dynamical systems with piecewise real-analytic inputs do not exhibit Zeno behavior. Applied the achieved result to affine complementarity systems with inputs, we also obtained a similar conclusion. A direct benefit of the main result is that one can apply smooth ordinary differential equations theory in a local manner for the analysis of continuous piecewise affine dynamical systems with inputs.

  10. Capturing Near Earth Objects

    OpenAIRE

    Baoyin, Hexi; CHEN Yang; Li, Junfeng

    2011-01-01

    Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting object after a small...

  11. Large deviations for tandem queueing systems

    Directory of Open Access Journals (Sweden)

    Roland L. Dobrushin

    1994-01-01

    Full Text Available The crude asymptotics of the large delay probability in a tandem queueing system is considered. The main result states that one of the two channels in the tandem system defines the crude asymptotics. The constant that determines the crude asymptotics is given. The results obtained are based on the large deviation principle for random processes with independent increments on an infinite interval recently established by the authors.

  12. The Cutting Edge of Affinity Electrophoresis Technology

    Directory of Open Access Journals (Sweden)

    Eiji Kinoshita

    2015-03-01

    Full Text Available Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years.

  13. The Cutting Edge of Affinity Electrophoresis Technology

    Science.gov (United States)

    Kinoshita, Eiji; Kinoshita-Kikuta, Emiko; Koike, Tohru

    2015-01-01

    Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years.

  14. Capturing enveloped viruses on affinity grids for downstream cryo-electron microscopy applications

    Science.gov (United States)

    Electron microscopy cryo-electron microscopy and cryo-electron tomography are essential techniques used for characterizing basic virus morphology and determining the three-dimensional structure of viruses. Enveloped viruses, which contain an outer lipoprotein coat, constitute the largest group of pa...

  15. Corner Transfer Matrices and Quantum Affine Algebras

    CERN Document Server

    Foda, O E; Foda, Omar; Miwa, Tetsuji

    1992-01-01

    Let H be the corner-transfer-matrix Hamiltonian for the six-vertex model in the anti-ferroelectric regime. It acts on the infinite tensor product W = V . V . V ....., where is the 2-dimensional irreducible representation of the quantum affine sl(2). We observe that H is the derivation of quantum affine sl(2), and conjecture that the eigenvectors of H form the level-1 vacuum representation of quantum affine sl(2). We report on checks in support of our conjecture.

  16. Affinization of category O for quantum groups

    CERN Document Server

    Young, C A S

    2012-01-01

    Let g be a simple Lie algebra. We consider the category O-hat of those modules over the affine quantum group Uq(g-hat) whose Uq(g)-weights have finite multiplicity and lie in a finite union of cones generated by negative roots. We show that many properties of the category of the finite-dimensional representations naturally extend to the category O-hat. In particular, we develop the theory of q-characters and define the minimal affinizations of parabolic Verma modules. In types ABCFG we classify these minimal affinizations and conjecture a Weyl denominator type formula for their characters.

  17. Bait type influences on catch and bycatch in tandem hoop nets set in reservoirs

    Science.gov (United States)

    Long, James M.; Stewart, David R.; Shiflet, Jeremy; Balsman, Dane; Shoup, Daniel E.

    2017-01-01

    Tandem hoop nets have become the primary gear for sampling channel catfish Ictalurus punctatus, but suffer from high incidences of bycatch, particularly aquatic turtles that usually drown as a result. We sought to determine if bait type, ZOTE© soap and ground cheese logs, would influence catch of channel catfish (CPUE and mean TL) and bycatch of fishes and aquatic turtles. We sampled with tandem hoop nets in 13 Kentucky reservoirs (5–73 ha) using a crossover design and two sampling events. We found no difference in channel catfish catch rates between bait types, but mean sizes of fish caught using ZOTE© soap were approximately 24 mm longer compared to cheese. Fish bycatch was similar between bait types, but tandem hoop nets baited with ZOTE© soap caught up to 61% fewer turtles and mortality of turtles that were captured was up to 12% lower than those baited with cheese. Depth of net set, water temperature, and Secchi depth were environmental factors measured that affected catch and bycatch, but varied among species. Using ZOTE© soap as bait in tandem hoop nets appears to be a fairly simple and straightforward method for maintaining high catch rates of channel catfish while minimizing turtle mortality.

  18. Large-scale analysis of tandem repeat variability in the human genome.

    Science.gov (United States)

    Duitama, Jorge; Zablotskaya, Alena; Gemayel, Rita; Jansen, An; Belet, Stefanie; Vermeesch, Joris R; Verstrepen, Kevin J; Froyen, Guy

    2014-05-01

    Tandem repeats are short DNA sequences that are repeated head-to-tail with a propensity to be variable. They constitute a significant proportion of the human genome, also occurring within coding and regulatory regions. Variation in these repeats can alter the function and/or expression of genes allowing organisms to swiftly adapt to novel environments. Importantly, some repeat expansions have also been linked to certain neurodegenerative diseases. Therefore, accurate sequencing of tandem repeats could contribute to our understanding of common phenotypic variability and might uncover missing genetic factors in idiopathic clinical conditions. However, despite long-standing evidence for the functional role of repeats, they are largely ignored because of technical limitations in sequencing, mapping and typing. Here, we report on a novel capture technique and data filtering protocol that allowed simultaneous sequencing of thousands of tandem repeats in the human genomes of a three generation family using GS-FLX-plus Titanium technology. Our results demonstrated that up to 7.6% of tandem repeats in this family (4% in coding sequences) differ from the reference sequence, and identified a de novo variation in the family tree. The method opens new routes to look at this underappreciated type of genetic variability, including the identification of novel disease-related repeats.

  19. The ground and excited state electron affinities of cytosine and trans-azobenzene

    Science.gov (United States)

    Chen, Edward C. M.; Herder, Charles; Chen, Edward S.

    2007-06-01

    The electron capture detector, reduction potential, electron transfer and photon methods of determining electron affinities are compared. The adiabatic electron affinities are (in eV): t-azobenzene(O 2), 1.578(5); t-azobenzene, 1.378(5); cytosine, 1.043(5) from anion photoelectron spectra. The largest or ground state value for trans-azobenzene and an excited state electron affinity for cytosine, 0.70 eV are also determined by reduction potentials. Other excited state energies are (in eV): t-azobenzene, 0.328(5), 0.589(5), 0.690(5), 0.768(5), 0.954(5), 1.038(5), 1.150(5), 1.275(5) and cytosine, 0.089(5), 0.098(5), 0.198(5), 0.235(5). The cytosine values are consistent with electron transport and radiation damage and repair in DNA.

  20. Neutron capture reactions at DANCE

    Science.gov (United States)

    Bredeweg, T. A.

    2008-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) is a 4π BaF2 array consisting of 160 active detector elements. The primary purpose of the array is to perform neutron capture cross section measurements on small (>~100 μg) and/or radioactive (DANCE we have performed neutron capture cross section measurements on a wide array of medium to heavy mass nuclides. Measurements to date include neutron capture cross sections on 241,243Am, neutron capture and neutron-induced fission cross sections and capture-to-fission ratio (α = σγ/σf) for 235U using a new fission-tagging detector as well as neutron capture cross sections for several astrophysics branch-point nuclei. Results from several of these measurements will be presented along with a discussion of additional physics information that can be extracted from the DANCE data.

  1. Innate immunity probed by lipopolysaccharides affinity strategy and proteomics.

    Science.gov (United States)

    Giangrande, Chiara; Colarusso, Lucia; Lanzetta, Rosa; Molinaro, Antonio; Pucci, Piero; Amoresano, Angela

    2013-01-01

    Lipopolysaccharides (LPSs) are ubiquitous and vital components of the cell surface of Gram-negative bacteria that have been shown to play a relevant role in the induction of the immune-system response. In animal and plant cells, innate immune defenses toward microorganisms are triggered by the perception of pathogen associated molecular patterns. These are conserved and generally indispensable microbial structures such as LPSs that are fundamental in the Gram-negative immunity recognition. This paper reports the development of an integrated strategy based on lipopolysaccharide affinity methodology that represents a new starting point to elucidate the molecular mechanisms elicited by bacterial LPS and involved in the different steps of innate immunity response. Biotin-tagged LPS was immobilized on streptavidin column and used as a bait in an affinity capture procedure to identify protein partners from human serum specifically interacting with this effector. The complex proteins/lipopolysaccharide was isolated and the protein partners were fractionated by gel electrophoresis and identified by mass spectrometry. This procedure proved to be very effective in specifically binding proteins functionally correlated with the biological role of LPS. Proteins specifically bound to LPS essentially gathered within two functional groups, regulation of the complement system (factor H, C4b, C4BP, and alpha 2 macroglobulin) and inhibition of LPS-induced inflammation (HRG and Apolipoproteins). The reported strategy might have important applications in the elucidation of biological mechanisms involved in the LPSs-mediated molecular recognition and anti-infection responses.

  2. Fatty acid and drug binding to a low-affinity component of human serum albumin, purified by affinity chromatography

    DEFF Research Database (Denmark)

    Vorum, H; Pedersen, A O; Honoré, B

    1992-01-01

    of two albumin components about 40% of the albumin having high affinity and about 60% having low affinity. By affinity chromatography we succeeded in purifying the low-affinity component from the mixture. The high-affinity component, however, could not be isolated. We further analyzed the fatty acid...

  3. Robust automated knowledge capture.

    Energy Technology Data Exchange (ETDEWEB)

    Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt

    2011-10-01

    This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.

  4. Capturing the uncultivated majority

    Energy Technology Data Exchange (ETDEWEB)

    Green, Brian D.; Keller, Martin

    2007-04-02

    The metagenomic analysis of environmental microbialcommunities continues to be a rapidly developing area of study. DNAisolation, the first step in capturing the uncultivated majority, hasseen many advances in recent years. Protocols have been developed todistinguish DNA from live versus dead cells and to separate extracellularfrom intracellular DNA. Looking to increase our understanding of the rolethat members of a microbial community play in ecological processes,several techniques have been developed that are enabling greater indepthanalysis of environmental metagenomes. These include the development ofenvironmental gene tags and the serial analysis of 16S rRNA gene sequencetags. In addition, new screening methods have been designed to select forspecific functional genes within metagenomic libraries. Finally, newcultivation methods continue to be developed to improve our ability tocapture a greater diversity of microorganisms within theenvironment.

  5. Capturing the Daylight Dividend

    Energy Technology Data Exchange (ETDEWEB)

    Peter Boyce; Claudia Hunter; Owen Howlett

    2006-04-30

    Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach.

  6. Scaling laws in phytoplankton nutrient uptake affinity

    DEFF Research Database (Denmark)

    Lindemann, Christian; Fiksen, Øyvind; Andersen, Ken Haste

    2016-01-01

    Nutrient uptake affinity affects the competitive ability of microbial organisms at low nutrient concentrations. From the theory of diffusion limitation it follows that uptake affinity scales linearly with the cell radius. This is in conflict with some observations suggesting that uptake affinity...... scales to a quantity that is closer to the square of the radius, i.e. to cell surface area. We show that this apparent conflict can be resolved by nutrient uptake theory. Pure diffusion limitation assumes that the cell is a perfect sink which means that it is able to absorb all encountered nutrients...... to volume ratio. We show that there are two reasons for this. First, because the small cells need a higher transporter density in order to maximize their affinity, and second because the relative cost of a transporter is higher for a small than for a large cell. We suggest that this might explain why...

  7. Protein purification using PDZ affinity chromatography.

    Science.gov (United States)

    Walkup, Ward G; Kennedy, Mary B

    2015-04-01

    PDZ domains function in nature as protein-binding domains within scaffold and membrane-associated proteins. They comprise approximately 90 residues and undergo specific, high-affinity interactions with complementary C-terminal peptide sequences, other PDZ domains, and/or phospholipids. We have previously shown that the specific, strong interactions of PDZ domains with their ligands make them well suited for use in affinity chromatography. This unit provides protocols for the PDZ affinity chromatography procedure that are applicable for the purification of proteins that contain PDZ domains or PDZ domain-binding ligands, either naturally or introduced by genetic engineering. We detail the preparation of affinity resins composed of PDZ domains or PDZ domain peptide ligands coupled to solid supports. These resins can be used to purify proteins containing endogenous or genetically introduced PDZ domains or ligands, eluting the proteins with free PDZ domain peptide ligands.

  8. Preparation and characterization of fluorophenylboronic acid-functionalized affinity monolithic columns for the selective enrichment of cis-diol-containing biomolecules.

    Science.gov (United States)

    Li, Qianjin; Liu, Zhen

    2015-01-01

    Boronate affinity monolithic columns have been developed into an important means for the selective recognition and capture of cis-diol-containing biomolecules, such as glycoproteins, nucleosides and saccharides. The ligands of boronic acids are playing an important role in boronate affinity monolithic columns. Although several boronate affinity monoliths with high affinity toward cis-diol-containing biomolecules have been reported, only few publications are focused on their detailed procedures for preparation and characterization. This chapter describes in detail the preparation and characterization of a boronate affinity monolithic column applying 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) as a ligand. The DFFPBA-functionalized monolithic column not only exhibited an ultrahigh boronate affinity toward cis-diol-containing biomolecules, but also showed great potential for the selective enrichment of cis-diol-containing biomolecules in real samples.

  9. Molecular-level Insight into Unusual Low Pressure CO2 Affinity in Pillared Metal-Organic Frameworks

    NARCIS (Netherlands)

    Burtch, N.C.; Jasuja, H.; Dubbeldam, D.; Walton, K.S.

    2013-01-01

    Fundamental insight into how low pressure adsorption properties are affected by chemical functionalization is critical to the development of next-generation porous materials for postcombustion CO2 capture. In this work, we present a systematic approach to understanding low pressure CO2 affinity in i

  10. APPROXIMATE OUTPUT REGULATION FOR AFFINE NONLINEAR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yali DONG; Daizhan CHENG; Huashu QIN

    2003-01-01

    Output regulation for affine nonlinear systems driven by an exogenous signal is investigated in this paper. In the absence of the standard exosystem hypothesis, we assume availability of the instantaneous values of the exogenous signal and its first time-derivative for use in the control law.For affine nonlinear systems, the necessary and sufficient conditions of the solvability of approximate output regulation problem are obtained. The precise form of the control law is presented under some suitable assumptions.

  11. Applications of new affine invariant for polytopes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To study the Schneider's projection problem,Lutwak,Yang and Zhang recently introduced a new .affine invariant functional U(P) for convex polytopes in Rn.In the paper,we obtain the analytic expression of the affine-invariant U(P) defined on a specific subclass of origin-symmetric convex polytopes in Rn and give an application of U(P) to the Lp-Minkowski problem.

  12. Fan affinity laws from a collision model

    CERN Document Server

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated from hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this work we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan.

  13. A new series of emodin derivatives with bone affinity

    Institute of Scientific and Technical Information of China (English)

    Hong Chen; Ying Wang; Ling Leng; Mao Sheng Cheng; Peng Fei Yu; Jing Ze Zhang

    2007-01-01

    A new series of bone affinity compounds were synthesized by linking emodin with 5-fluorouracil derivatives. Their bone affinities were established by hydroxyapative (HA) affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.

  14. Synthesis of a New Series of Bone Affinity Compounds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.

  15. Microsatellite DNA capture from enriched libraries.

    Science.gov (United States)

    Gonzalez, Elena G; Zardoya, Rafael

    2013-01-01

    Microsatellites are DNA sequences of tandem repeats of one to six nucleotides, which are highly polymorphic, and thus the molecular markers of choice in many kinship, population genetic, and conservation studies. There have been significant technical improvements since the early methods for microsatellite isolation were developed, and today the most common procedures take advantage of the hybrid capture methods of enriched-targeted microsatellite DNA. Furthermore, recent advents in sequencing technologies (i.e., next-generation sequencing, NGS) have fostered the mining of microsatellite markers in non-model organisms, affording a cost-effective way of obtaining a large amount of sequence data potentially useful for loci characterization. The rapid improvements of NGS platforms together with the increase in available microsatellite information open new avenues to the understanding of the evolutionary forces that shape genetic structuring in wild populations. Here, we provide detailed methodological procedures for microsatellite isolation based on the screening of GT microsatellite-enriched libraries, either by cloning and Sanger sequencing of positive clones or by direct NGS. Guides for designing new species-specific primers and basic genotyping are also given.

  16. The connection between metal ion affinity and ligand affinity in integrin I domains

    DEFF Research Database (Denmark)

    Vorup-Jensen, Thomas; Waldron, TT; Astrof, N;

    2007-01-01

    Integrins are cell-surface heterodimeric proteins that mediate cell-cell, cell-matrix, and cell-pathogen interactions. Half of the known integrin alpha subunits contain inserted domains (I domains) that coordinate ligand through a metal ion. Although the importance of conformational changes within...... isolated I domains in regulating ligand binding has been reported, the relationship between metal ion binding affinity and ligand binding affinity has not been elucidated. Metal and ligand binding by several I domain mutants that are stabilized in different conformations are investigated using isothermal...... titration calorimetry and surface plasmon resonance studies. This work suggests an inverse relationship between metal ion affinity and ligand binding affinity (i.e. constructs with a high affinity for ligand exhibit a low affinity for metal). This trend is discussed in the context of structural studies...

  17. Starch‐binding domains in the CBM45 family – low‐affinity domains from glucan, water dikinase and α‐amylase involved in plastidial starch metabolism

    DEFF Research Database (Denmark)

    Glaring, Mikkel Andreas; Baumann, Martin; Abou Hachem, Maher

    2011-01-01

    Starch‐binding domains are noncatalytic carbohydrate‐binding modules that mediate binding to granular starch. The starch‐binding domains from the carbohydrate‐binding module family 45 (CBM45, ) are found as N‐terminal tandem repeats in a small number of enzymes, primarily from photosynthesizing...... amylolytic enzymes. This suggests that low‐affinity starch‐binding domains are a recurring feature in plastidial starch metabolism, and supports the hypothesis that reversible binding, effectuated through low‐affinity interaction with starch granules, facilitates dynamic regulation of enzyme activities and...

  18. The combinatorics of tandem duplication trees.

    Science.gov (United States)

    Gascuel, Olivier; Hendy, Michael D; Jean-Marie, Alain; McLachlan, Robert

    2003-02-01

    We developed a recurrence relation that counts the number of tandem duplication trees (either rooted or unrooted) that are consistent with a set of n tandemly repeated sequences generated under the standard unequal recombination (or crossover) model of tandem duplications. The number of rooted duplication trees is exactly twice the number of unrooted trees, which means that on average only two positions for a root on a duplication tree are possible. Using the recurrence, we tabulated these numbers for small values of n. We also developed an asymptotic formula that for large n provides estimates for these numbers. These numbers give a priori probabilities for phylogenies of the repeated sequences to be duplication trees. This work extends earlier studies where exhaustive counts of the numbers for small n were obtained. One application showed the significance of finding that most maximum-parsimony trees constructed from repeat sequences from human immunoglobins and T-cell receptors were tandem duplication trees. Those findings provided strong support to the proposed mechanisms of tandem gene duplication. The recurrence relation also suggests efficient algorithms to recognize duplication trees and to generate random duplication trees for simulation. We present a linear-time recognition algorithm.

  19. Tandemly Arrayed Genes in Vertebrate Genomes

    Directory of Open Access Journals (Sweden)

    Deng Pan

    2008-01-01

    Full Text Available Tandemly arrayed genes (TAGs are duplicated genes that are linked as neighbors on a chromosome, many of which have important physiological and biochemical functions. Here we performed a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72–94% have parallel transcription orientation (i.e., they are encoded on the same strand in contrast to the genome, which has about 50% of its genes in parallel transcription orientation. The majority of tandem arrays have only two members. In all species, the proportion of genes that belong to TAGs tends to be higher in large gene families than in small ones; together with our recent finding that tandem duplication played a more important role than retroposition in large families, this fact suggests that among all types of duplication mechanisms, tandem duplication is the predominant mechanism of duplication, especially in large families. Finally, several species have a higher proportion of large tandem arrays that are species-specific than random expectation.

  20. Crystal structure of the three tandem FF domains of the transcription elongation regulator CA150.

    Science.gov (United States)

    Lu, Ming; Yang, Jun; Ren, Zhiyong; Sabui, Subir; Espejo, Alexsandra; Bedford, Mark T; Jacobson, Raymond H; Jeruzalmi, David; McMurray, John S; Chen, Xiaomin

    2009-10-23

    FF domains are small protein-protein interaction modules that have two flanking conserved phenylalanine residues. They are present in proteins involved in transcription, RNA splicing, and signal transduction, and often exist in tandem arrays. Although several individual FF domain structures have been determined by NMR, the tandem nature of most FF domains has not been revealed. Here we report the 2.7-A-resolution crystal structure of the first three FF domains of the human transcription elongation factor CA150. Each FF domain is composed of three alpha-helices and a 3(10) helix between alpha-helix 2 and alpha-helix 3. The most striking feature of the structure is that an FF domain is connected to the next by an alpha-helix that continues from helix 3 to helix 1 of the next. The consequent elongated arrangement allows exposure of many charged residues within the region that can be engaged in interaction with other molecules. Binding studies using a peptide ligand suggest that a specific conformation of the FF domains might be required to achieve higher-affinity binding. Additionally, we explore potential DNA binding of the FF construct used in this study. Overall, we provide the first crystal structure of an FF domain and insights into the tandem nature of the FF domains and suggest that, in addition to protein binding, FF domains might be involved in DNA binding.

  1. Trojan capture by terrestrial planets

    CERN Document Server

    Schwarz, Richard

    2016-01-01

    The paper is devoted to investigate the capture of asteroids by Venus, Earth and Mars into the 1:1 mean motion resonance especially into Trojan orbits. Current theoretical studies predict that Trojan asteroids are a frequent by-product of the planet formation. This is not only the case for the outer giant planets, but also for the terrestrial planets in the inner Solar System. By using numerical integrations, we investigated the capture efficiency and the stability of the captured objects. We found out that the capture efficiency is larger for the planets in the inner Solar System compared to the outer ones, but most of the captured Trojan asteroids are not long term stable. This temporary captures caused by chaotic behaviour of the objects were investigated without any dissipative forces. They show an interesting dynamical behaviour of mixing like jumping from one Lagrange point to the other one.

  2. The Generic Data Capture Facility

    Science.gov (United States)

    Connell, Edward B.; Barnes, William P.; Stallings, William H.

    The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.

  3. Captured by Aliens

    Science.gov (United States)

    Achenbach, Joel

    2000-03-01

    Captured by Aliens is a long and twisted voyage from science to the supernatural and back again. I hung out in Roswell, N.M., spent time with the Mars Society, met a guy who was figuring out the best way to build a spaceship to go to Alpha Centauri. I visited the set of the X-Files and talked to Mulder and Scully. One day over breakfast I was told by NASA administrator Dan Goldin, We live in a fog, man! He wants the big answers to the big questions. I spent a night in the base of a huge radio telescope in the boondocks of West Virginia, awaiting the signal from the aliens. I was hypnotized in a hotel room by someone who suspected that I'd been abducted by aliens and that this had triggered my interest in the topic. In the last months of his life, I talked to Carl Sagan, who believed that the galaxy riots with intelligent civilizations. He's my hero, for his steadfast adherence to the scientific method. What I found in all this is that the big question that needs immediate attention is not what's out THERE, but what's going on HERE, on Earth, and why we think the way we do, and how we came to be here in the first place.

  4. Capture-recapture methodology

    Science.gov (United States)

    Gould, William R.; Kendall, William L.

    2013-01-01

    Capture-recapture methods were initially developed to estimate human population abundance, but since that time have seen widespread use for fish and wildlife populations to estimate and model various parameters of population, metapopulation, and disease dynamics. Repeated sampling of marked animals provides information for estimating abundance and tracking the fate of individuals in the face of imperfect detection. Mark types have evolved from clipping or tagging to use of noninvasive methods such as photography of natural markings and DNA collection from feces. Survival estimation has been emphasized more recently as have transition probabilities between life history states and/or geographical locations, even where some states are unobservable or uncertain. Sophisticated software has been developed to handle highly parameterized models, including environmental and individual covariates, to conduct model selection, and to employ various estimation approaches such as maximum likelihood and Bayesian approaches. With these user-friendly tools, complex statistical models for studying population dynamics have been made available to ecologists. The future will include a continuing trend toward integrating data types, both for tagged and untagged individuals, to produce more precise and robust population models.

  5. Inland capture fisheries.

    Science.gov (United States)

    Welcomme, Robin L; Cowx, Ian G; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-09-27

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.

  6. Gaussian and Affine Approximation of Stochastic Diffusion Models for Interest and Mortality Rates

    Directory of Open Access Journals (Sweden)

    Marcus C. Christiansen

    2013-10-01

    Full Text Available In the actuarial literature, it has become common practice to model future capital returns and mortality rates stochastically in order to capture market risk and forecasting risk. Although interest rates often should and mortality rates always have to be non-negative, many authors use stochastic diffusion models with an affine drift term and additive noise. As a result, the diffusion process is Gaussian and, thus, analytically tractable, but negative values occur with positive probability. The argument is that the class of Gaussian diffusions would be a good approximation of the real future development. We challenge that reasoning and study the asymptotics of diffusion processes with affine drift and a general noise term with corresponding diffusion processes with an affine drift term and an affine noise term or additive noise. Our study helps to quantify the error that is made by approximating diffusive interest and mortality rate models with Gaussian diffusions and affine diffusions. In particular, we discuss forward interest and forward mortality rates and the error that approximations cause on the valuation of life insurance claims.

  7. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  8. Tandem transformation of glycerol to esters.

    Science.gov (United States)

    Sotenko, Maria V; Rebroš, Martin; Sans, Victor S; Loponov, Konstantin N; Davidson, Matthew G; Stephens, Gill; Lapkin, Alexei A

    2012-12-31

    Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process.

  9. Laser Ablation with Vacuum Capture for MALDI Mass Spectrometry of Tissue

    Science.gov (United States)

    Donnarumma, Fabrizio; Cao, Fan; Murray, Kermit K.

    2016-01-01

    We have developed a laser ablation sampling technique for matrix-assisted laser desorption ionization (MALDI) mass spectrometry and tandem mass spectrometry (MS/MS) analyses of in-situ digested tissue proteins. Infrared laser ablation was used to remove biomolecules from tissue sections for collection by vacuum capture and analysis by MALDI. Ablation and transfer of compounds from tissue removes biomolecules from the tissue and allows further analysis of the collected material to facilitate their identification. Laser ablated material was captured in a vacuum aspirated pipette-tip packed with C18 stationary phase and the captured material was dissolved, eluted, and analyzed by MALDI. Rat brain and lung tissue sections 10 μm thick were processed by in-situ trypsin digestion after lipid and salt removal. The tryptic peptides were ablated with a focused mid-infrared laser, vacuum captured, and eluted with an acetonitrile/water mixture. Eluted components were deposited on a MALDI target and mixed with matrix for mass spectrometry analysis. Initial experiments were conducted with peptide and protein standards for evaluation of transfer efficiency: a transfer efficiency of 16% was obtained using seven different standards. Laser ablation vacuum capture was applied to freshly digested tissue sections and compared with sections processed with conventional MALDI imaging. A greater signal intensity and lower background was observed in comparison with the conventional MALDI analysis. Tandem time-of-flight MALDI mass spectrometry was used for compound identification in the tissue.

  10. Classification of neocortical interneurons using affinity propagation

    Science.gov (United States)

    Santana, Roberto; McGarry, Laura M.; Bielza, Concha; Larrañaga, Pedro; Yuste, Rafael

    2013-01-01

    In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. In fact, neuronal classification is a difficult problem because it is unclear how to designate a neuronal cell class and what are the best characteristics to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological, or molecular characteristics, have provided quantitative and unbiased identification of distinct neuronal subtypes, when applied to selected datasets. However, better and more robust classification methods are needed for increasingly complex and larger datasets. Here, we explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. Affinity propagation outperformed Ward's method, a current standard clustering approach, in classifying the neurons into 4 subtypes. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits. PMID:24348339

  11. Classification of neocortical interneurons using affinity propagation.

    Science.gov (United States)

    Santana, Roberto; McGarry, Laura M; Bielza, Concha; Larrañaga, Pedro; Yuste, Rafael

    2013-01-01

    In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. In fact, neuronal classification is a difficult problem because it is unclear how to designate a neuronal cell class and what are the best characteristics to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological, or molecular characteristics, have provided quantitative and unbiased identification of distinct neuronal subtypes, when applied to selected datasets. However, better and more robust classification methods are needed for increasingly complex and larger datasets. Here, we explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. Affinity propagation outperformed Ward's method, a current standard clustering approach, in classifying the neurons into 4 subtypes. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.

  12. Proton Affinity Calculations with High Level Methods.

    Science.gov (United States)

    Kolboe, Stein

    2014-08-12

    Proton affinities, stretching from small reference compounds, up to the methylbenzenes and naphthalene and anthracene, have been calculated with high accuracy computational methods, viz. W1BD, G4, G3B3, CBS-QB3, and M06-2X. Computed and the currently accepted reference proton affinities are generally in excellent accord, but there are deviations. The literature value for propene appears to be 6-7 kJ/mol too high. Reported proton affinities for the methylbenzenes seem 4-5 kJ/mol too high. G4 and G3 computations generally give results in good accord with the high level W1BD. Proton affinity values computed with the CBS-QB3 scheme are too low, and the error increases with increasing molecule size, reaching nearly 10 kJ/mol for the xylenes. The functional M06-2X fails markedly for some of the small reference compounds, in particular, for CO and ketene, but calculates methylbenzene proton affinities with high accuracy.

  13. Stepparents' Affinity-Seeking and Affinity-Maintaining Strategies with Stepchildren.

    Science.gov (United States)

    Ganong, Lawrence; Coleman, Marilyn; Fine, Mark; Martin, Patricia

    1999-01-01

    Examines the strategies that stepparents use to develop and maintain affinity with stepchildren and the effects that these strategies have on the development of stepparent-stepchildren relationships. Thirty-one affinity-seeking strategies are identified. Results show that dyadic activities worked best, but it is important that stepchildren…

  14. Selective dispersive solid phase extraction-chromatography tandem mass spectrometry based on aptamer-functionalized UiO-66-NH2 for determination of polychlorinated biphenyls.

    Science.gov (United States)

    Lin, Saichai; Gan, Ning; Cao, Yuting; Chen, Yinji; Jiang, Qianli

    2016-05-13

    In this paper, a novel dispersive solid phase extraction (dSPE) adsorbent based on aptamer-functionalized magnetic metal-organic framework material was developed for selective enrichment of the trace polychlorinated biphenyls (PCBs) from soil sample. Firstly, we developed a simple, versatile synthetic strategy to prepare highly reproducible magnetic amino-functionalized UiO-66 (Fe3O4@PDA@UiO-66-NH2) by using polydopamine (PDA) as covalent linker. Then amino-functionalized aptamers which can recognize 2,3',5,5'-tetrachlorobiphenyl (PCB72), 2',3',4',5,5'-pentachlorobiphenyl (PCB106) were covalent immobilized on UiO-66-NH2 through coupling reagent of glutaraldehyde. Aptamer-functionalized adsorbent (Fe3O4@PDA@UiO-66-Apt) can specifically capture PCBs from complex matrix with high adsorption capacity based on the specific affinity of aptamer towards target. Moreover, the adsorbent can be easily isolated from the solution through magnetic separation after extraction. Afterwards, the detection was carried out with gas chromatography tandem mass spectrometry (GC-MS). The selective dSPE pretreatment coupled with GC-MS possessed high selectivity, good binding capacity, stability, repeatability and reproducibility for the extraction of PCBs. Furthermore, the adsorbent possessed good mechanical stability which can be applied in replicate at least for 60 extraction cycles with recovery over 80%. It provided a linear range of 0.02-400ngmL(-1) with a good correlation coefficient (R(2)=0.9994-0.9996), and the limit of detection was found to be 0.010-0.015ngmL(-1). The method was successfully utilized for the determination of PCBs in soil samples.

  15. New opioid affinity labels containing maleoyl moiety.

    Science.gov (United States)

    Szatmári, I; Orosz, G; Rónai, A Z; Makó, E; Medzihradszky, K; Borsodi, A

    1999-01-01

    Opioid receptor binding properties and pharmacological profiles of novel peptides containing maleoyl function were determined in order to develop new affinity labels. Based on the enkephalin structure peptide ligands were synthesized and tested. Both in in vitro receptor binding experiments and pharmacological studies, all ligands showed agonist character with relatively high affinity (Ki values in the nanomolar range) and good to moderate selectivity. Replacement of Gly2 in the enkephalin frame with D-Ala led to higher affinities with a small decrease in selectivity. The longer peptide chains resulted in compounds with high percentage (up to 86%) of irreversible binding. The selectivity pattern of the ligands is in good agreement with the data obtained from the pharmacological assays (guinea pig ileum and mouse vas deferens bioassays). The newly synthesized peptides could be used in further studies in order to determine more detailed characteristics of the ligand-receptor interaction.

  16. On Affine Fusion and the Phase Model

    Directory of Open Access Journals (Sweden)

    Mark A. Walton

    2012-11-01

    Full Text Available A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n Wess-Zumino-Novikov-Witten (WZNW conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connection to the modular S matrix and fusion of the su(n WZNW model. The noncommutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.

  17. Modelling and simulation of affinity membrane adsorption.

    Science.gov (United States)

    Boi, Cristiana; Dimartino, Simone; Sarti, Giulio C

    2007-08-24

    A mathematical model for the adsorption of biomolecules on affinity membranes is presented. The model considers convection, diffusion and adsorption kinetics on the membrane module as well as the influence of dead end volumes and lag times; an analysis of flow distribution on the whole system is also included. The parameters used in the simulations were obtained from equilibrium and dynamic experimental data measured for the adsorption of human IgG on A2P-Sartoepoxy affinity membranes. The identification of a bi-Langmuir kinetic mechanisms for the experimental system investigated was paramount for a correct process description and the simulated breakthrough curves were in good agreement with the experimental data. The proposed model provides a new insight into the phenomena involved in the adsorption on affinity membranes and it is a valuable tool to assess the use of membrane adsorbers in large scale processes.

  18. Carbon Capture: A Technology Assessment

    Science.gov (United States)

    2013-10-21

    monoethanolamine (MEA) and ammonia ; pre- combustion capture (also via chemical solvents) from the synthesis gas produced in an integrated coal gasification...71 D. Heaven et al., “ Synthesis Gas Purification in Gasification to Ammonia /Urea Plants,” Gasification Technologies...32 Ammonia -Based Capture Processes

  19. Muon capture on Chlorine-35

    CERN Document Server

    Arole, S; Gorringe, T P; Hasinoff, M D; Kovash, M A; Kuzmin, V; Moftah, B A; Sedlar, R; Stocki, T J; Tetereva, T

    2002-01-01

    We report measurements of $\\gamma$--ray spectra from muon capture on $^{35}$Cl. For the allowed Gamow--Teller transitions to the $^{35}$S$(2939, 3/2^+)$ state and the $^{35}$S$(3421, 5/2^+)$ state we obtained their capture rates, hyperfine dependences and $\\gamma$--$\

  20. On neutrinoless double electron capture

    CERN Document Server

    Drukarev, E G

    2016-01-01

    We found the probability for the neutrinoless double electron capture in the case of $KK$ capture. We clarified the mechanism of the energy transfer from the nucleus to the bound electrons. This enabled us to obtain the equations for the probability of the $2EC0\

  1. Unraveling the Roots of Selectivity of Peptide Affinity Reagents for Structurally Similar Ribosomal Inactivating Protein Derivatives

    Directory of Open Access Journals (Sweden)

    Deborah A. Sarkes

    2016-11-01

    Full Text Available Peptide capture agents have become increasingly useful tools for a variety of sensing applications due to their ease of discovery, stability, and robustness. Despite the ability to rapidly discover candidates through biopanning bacterial display libraries and easily mature them to Protein Catalyzed Capture (PCC agents with even higher affinity and selectivity, an ongoing challenge and critical selection criteria is that the peptide candidates and final reagent be selective enough to replace antibodies, the gold-standard across immunoassay platforms. Here, we have discovered peptide affinity reagents against abrax, a derivative of abrin with reduced toxicity. Using on-cell Fluorescence Activated Cell Sorting (FACS assays, we show that the peptides are highly selective for abrax over RiVax, a similar derivative of ricin originally designed as a vaccine, with significant structural homology to abrax. We rank the newly discovered peptides for strongest affinity and analyze three observed consensus sequences with varying affinity and specificity. The strongest (Tier 1 consensus was FWDTWF, which is highly aromatic and hydrophobic. To better understand the observed selectivity, we use the XPairIt peptide–protein docking protocol to analyze binding location predictions of the individual Tier 1 peptides and consensus on abrax and RiVax. The binding location profiles on the two proteins are quite distinct, which we determine is due to differences in pocket size, pocket environment (including hydrophobicity and electronegativity, and steric hindrance. This study provides a model system to show that peptide capture candidates can be quite selective for a structurally similar protein system, even without further maturation, and offers an in silico method of analysis for understanding binding and down-selecting candidates.

  2. Poisson Morphisms and Reduced Affine Poisson Group Actions

    Institute of Scientific and Technical Information of China (English)

    YANG Qi Lin

    2002-01-01

    We establish the concept of a quotient affine Poisson group, and study the reduced Poisson action of the quotient of an affine Poisson group G on the quotient of an affine Poisson G-variety V. The Poisson morphisms (including equivariant cases) between Poisson affine varieties are also discussed.

  3. Periodic cyclic homology of affine Hecke algebras

    CERN Document Server

    Solleveld, Maarten

    2009-01-01

    This is the author's PhD-thesis, which was written in 2006. The version posted here is identical to the printed one. Instead of an abstract, the short list of contents: Preface 5 1 Introduction 9 2 K-theory and cyclic type homology theories 13 3 Affine Hecke algebras 61 4 Reductive p-adic groups 103 5 Parameter deformations in affine Hecke algebras 129 6 Examples and calculations 169 A Crossed products 223 Bibliography 227 Index 237 Samenvatting 245 Curriculum vitae 253

  4. Control and estimation of piecewise affine systems

    CERN Document Server

    Xu, Jun

    2014-01-01

    As a powerful tool to study nonlinear systems and hybrid systems, piecewise affine (PWA) systems have been widely applied to mechanical systems. Control and Estimation of Piecewise Affine Systems presents several research findings relating to the control and estimation of PWA systems in one unified view. Chapters in this title discuss stability results of PWA systems, using piecewise quadratic Lyapunov functions and piecewise homogeneous polynomial Lyapunov functions. Explicit necessary and sufficient conditions for the controllability and reachability of a class of PWA systems are

  5. Einstein's gravity from an affine model

    CERN Document Server

    Castillo-Felisola, Oscar

    2015-01-01

    We show that the effective field equations for a recently formulated affine model of gravity, in the sector of a metric (torsion-free) connection, accept general Einstein manifolds --- with or without cosmological constant --- as solutions. Moreover, these effective field equations coincide with the ones obtained from a gravitational Yang--Mills theory known as Stephenson--Kilmister--Yang theory. Additionally, we find an equivalence between a minimally coupled massless scalar field in General Relativity with a "minimally" coupled scalar field in this affine model.

  6. Separation of Proteins by Electrophoretic Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    邺韶骅; 刘铮; 丁富新; 袁乃驹

    1999-01-01

    A new kind of electrophoretic affinity chromatography (EAC) for bioseparation was proposed,Separation by EAC was conducted in a multicompartment electrolyzer in which the affinity gel media were packed in one of the central compartments.The presence of an electric field accelerated the migration of proteins inside the gel matrix during adsorption and descrption processes,This led to the increase of the overall speed of separation,The present study was focused on the effect of the strength of the electric field on adsorption and desorption processes.

  7. Adsorption affinity of anions on metal oxyhydroxides

    Science.gov (United States)

    Pechenyuk, S. I.; Semushina, Yu. P.; Kuz'mich, L. F.

    2013-03-01

    The dependences of anion (phosphate, carbonate, sulfate, chromate, oxalate, tartrate, and citrate) adsorption affinity anions from geometric characteristics, acid-base properties, and complex forming ability are generalized. It is shown that adsorption depends on the nature of both the anions and the ionic medium and adsorbent. It is established that anions are generally grouped into the following series of adsorption affinity reduction: PO{4/3-}, CO{3/2-} > C2O{4/2-}, C(OH)(CH2)2(COO){3/3-}, (CHOH)2(COO){2/2-} > CrO{4/2-} ≫ SO{4/2-}.

  8. Affine Invariant Character Recognition by Progressive Removing

    Science.gov (United States)

    Iwamura, Masakazu; Horimatsu, Akira; Niwa, Ryo; Kise, Koichi; Uchida, Seiichi; Omachi, Shinichiro

    Recognizing characters in scene images suffering from perspective distortion is a challenge. Although there are some methods to overcome this difficulty, they are time-consuming. In this paper, we propose a set of affine invariant features and a new recognition scheme called “progressive removing” that can help reduce the processing time. Progressive removing gradually removes less feasible categories and skew angles by using multiple classifiers. We observed that progressive removing and the use of the affine invariant features reduced the processing time by about 60% in comparison to a trivial one without decreasing the recognition rate.

  9. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  10. Iodine neutron capture therapy

    Science.gov (United States)

    Ahmed, Kazi Fariduddin

    A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at

  11. Electron capture dissociation of singly and multiply phosphorylated peptides

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V

    2000-01-01

    Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from......(III)-affinity chromatography combined with nano-electrospray FTMS/ECD facilitated phosphopeptide analysis and amino acid sequencing from crude proteolytic peptide mixtures....

  12. Evidence of multi-affinity in the Japanese stock market

    Science.gov (United States)

    Katsuragi, Hiroaki

    2000-04-01

    Fluctuations of the Japanese stock market (Tokyo Stock Price Index: TOPIX) are analyzed using a multi-affine analysis method. In the research to date, only some simulated self-affine models have shown multi-affinity. In most experiments using observations of self-affine fractal profiles, multi-affinity has not been found. However, we find evidence of multi-affinity in fluctuations of the Japanese stock market (TOPIX). The qth-order Hurst exponent Hq varies with changes in q. This multi-affinity indicates that there are plural mechanisms that affect the same time scale as stock market price fluctuation dynamics.

  13. Tandem queue with server slow-down

    NARCIS (Netherlands)

    D.I. Miretskiy; W.R.W. Scheinhardt; M.R.H. Mandjes

    2007-01-01

    We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of job

  14. Modelling of tandem cell temperature coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, D.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper discusses the temperature dependence of the basic solar-cell operating parameters for a GaInP/GaAs series-connected two-terminal tandem cell. The effects of series resistance and of different incident solar spectra are also discussed.

  15. M/G/∞ tandem queues

    NARCIS (Netherlands)

    Boxma, O.J.

    1984-01-01

    We consider a series of queues with Poisson input. Each queueing system contains an infinite number of service channels. The service times in each channel have a general distribution. For this M/G∞ tandem model we obtain the joint time-dependent distribution of queue length and residual service tim

  16. The PSI/ETH tandem accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Synal, H.A.; Doebeli, M.; Fuhrmann, H.; Kubik, P.W.; Nebiker, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)] [and others

    1997-09-01

    The 1996 operation of the PSI/ETH tandem accelerator at ETH Hoenggerberg is summarised with a detailed compilation of the beam time statistics and the statistics of AMS samples for the different radioisotopes and for the major fields of research. (author) 2 tab.

  17. Evolution of the tandem mirror reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, G.A.; Logan, B.G.

    1982-03-09

    We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).

  18. Crossing Chris: Some Markerian Affinities

    Directory of Open Access Journals (Sweden)

    Adrian Martin

    2010-01-01

    -pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

    Abstract (E: This essay creatively explores a group of artists, writers, and other special individuals whose work or life story can be described as having an intriguing affinity with the protean career of Chris Marker. Avoiding the ‘usual suspects’ (such as Godard or Sebald, it discusses gossip columnist Milt Machlin, record collector Harry Smith, painter Gianfranco Baruchello, writer-filmmaker Edgardo Cozarinsky, and several others. From this constellation, a particular view of Markerian poetics emerges, touching upon the meanings of anonymity, storytelling, history and archiving.

     

    Abstract (F: Cet essai brosse de manière créative le portrait d’un groupe d'artistes, d'écrivains et d'autres personnes particulières dont le travail ou la biographie peuvent être décrits comme montrant une étrange mais certaine connivence avec la carrière protéiforme de Chris Marker. Evitant les lieux communs (comme Godard ou Sebald, cet article trace des références moins attendues :

  19. Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas

    KAUST Repository

    Polshettiwar, Vivek

    2013-06-20

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making materials, methods of capturing gas (e.g., CO.sub.2), and the like, and the like.

  20. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  1. Colliding waves in metric-affine gravity

    CERN Document Server

    García, A; Macías, A; Mielke, E W; Socorro, J; García, Alberto; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.; Socorro, José

    1998-01-01

    We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the collision possesses two spacelike Killing vectors.

  2. Classification of neocortical interneurons using affinity propagation

    Directory of Open Access Journals (Sweden)

    Roberto eSantana

    2013-12-01

    Full Text Available In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. Neuronal classification has been a difficult problem because it is unclear what a neuronal cell class actually is and what are the best characteristics are to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological or molecular characteristics, when applied to selected datasets, have provided quantitative and unbiased identification of distinct neuronal subtypes. However, better and more robust classification methods are needed for increasingly complex and larger datasets. We explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. In fact, using a combined anatomical/physiological dataset, our algorithm differentiated parvalbumin from somatostatin interneurons in 49 out of 50 cases. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.

  3. A High-Affinity Adenosine Kinase from Anopheles Gambiae

    Energy Technology Data Exchange (ETDEWEB)

    M Cassera; M Ho; E Merino; E Burgos; A Rinaldo-Matthis; S Almo; V Schramm

    2011-12-31

    Genome analysis revealed a mosquito orthologue of adenosine kinase in Anopheles gambiae (AgAK; the most important vector for the transmission of Plasmodium falciparum in Africa). P. falciparum are purine auxotrophs and do not express an adenosine kinase but rely on their hosts for purines. AgAK was kinetically characterized and found to have the highest affinity for adenosine (K{sub m} = 8.1 nM) of any known adenosine kinase. AgAK is specific for adenosine at the nucleoside site, but several nucleotide triphosphate phosphoryl donors are tolerated. The AgAK crystal structure with a bound bisubstrate analogue Ap{sub 4}A (2.0 {angstrom} resolution) reveals interactions for adenosine and ATP and the geometry for phosphoryl transfer. The polyphosphate charge is partly neutralized by a bound Mg{sup 2+} ion and an ion pair to a catalytic site Arg. The AgAK structure consists of a large catalytic core in a three-layer {alpha}/{beta}/{alpha} sandwich, and a small cap domain in contact with adenosine. The specificity and tight binding for adenosine arise from hydrogen bond interactions of Asn14, Leu16, Leu40, Leu133, Leu168, Phe168, and Thr171 and the backbone of Ile39 and Phe168 with the adenine ring as well as through hydrogen bond interactions between Asp18, Gly64, and Asn68 and the ribosyl 2'- and 3'-hydroxyl groups. The structure is more similar to that of human adenosine kinase (48% identical) than to that of AK from Toxoplasma gondii (31% identical). With this extraordinary affinity for AgAK, adenosine is efficiently captured and converted to AMP at near the diffusion limit, suggesting an important role for this enzyme in the maintenance of the adenine nucleotide pool. mRNA analysis verifies that AgAK transcripts are produced in the adult insects.

  4. High-Performance Sorbents for Carbon Dioxide Capture from Air

    Energy Technology Data Exchange (ETDEWEB)

    Sholl, David; Jones, Christopher

    2013-03-13

    This project has focused on capture of CO{sub 2} from ambient air (“air capture”). If this process is technically and economically feasible, it could potentially contribute to net reduction of CO{sub 2} emissions in ways that are complementary to better developed techniques for CO{sub 2} from concentrated point sources. We focused on cyclic adsorption processes for CO{sub 2} capture from air in which the entire cycle is performed at moderate temperatures. The project involved both experimental studies of sorbent materials and process level modeling of cyclic air capture processes. In our experimental work, a series of amine-functionalized silica adsorbents were prepared and characterized to determine the impact of molecular architecture on CO{sub 2} capture. Some key findings were: • Amine functionalized silicas can be prepared with high enough CO{sub 2} capacities under ambient conditions to merit consideration for use in air capture processes. • Primary amines are better candidates for CO{sub 2} capture than secondary or tertiary amines, both in terms of amine efficiency for CO{sub 2} adsorption and enhanced water affinity. • Mechanistic understanding of degradation of these materials can enable control of molecular architecture to significantly improve material stability. Our process modeling work provided the first publically available cost and energy estimates for cyclic adsorption processes for air capture of CO{sub 2}. Some key findings were: • Cycles based on diurnal ambient heating and cooling cannot yield useful purities or amounts of captured CO{sub 2}. • Cycles based on steam desorption at 110 oC can yield CO{sub 2} purities of ~88%. • The energy requirements for cycles using steam desorption are dominated by needs for thermal input, which results in lower costs than energy input in the form of electricity. Cyclic processes with operational costs of less than $100 tCO{sub 2}-net were described, and these results point to process and

  5. Provenance Datasets Highlighting Capture Disparities

    Science.gov (United States)

    2014-01-01

    the Web pages of the universities and institutes.1 Notes are made and links pasted in a variety of formats. Files are saved on a shared drive. When...institutions/ 3. Capture Methods There are several capture methods that are available for use [4]: • Manual capture. • Scraping of logs or...the high-level user desktop. Save links App: Word, SharePoint User: Alice Web Data Web Data Web Data Web Data Web Data Web Data Notes.txt Create

  6. Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, N H; Sen, J W; Nissen, Mogens Holst

    2000-01-01

    The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of......The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red...

  7. Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-12-16

    Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

  8. Tuning the Protein Corona of Hydrogel Nanoparticles: The Synthesis of Abiotic Protein and Peptide Affinity Reagents.

    Science.gov (United States)

    O'Brien, Jeffrey; Shea, Kenneth J

    2016-06-21

    Nanomaterials, when introduced into a complex, protein-rich environment, rapidly acquire a protein corona. The type and amount of proteins that constitute the corona depend significantly on the synthetic identity of the nanomaterial. For example, hydrogel nanoparticles (NPs) such as poly(N-isopropylacrylamide) (NIPAm) have little affinity for plasma proteins; in contrast, carboxylated poly(styrene) NPs acquire a dense protein corona. This range of protein adsorption suggests that the protein corona might be "tuned" by controlling the chemical composition of the NP. In this Account, we demonstrate that small libraries of synthetic polymer NPs incorporating a diverse pool of functional monomers can be screened for candidates with high affinity and selectivity to targeted biomacromolecules. Through directed synthetic evolution of NP compositions, one can tailor the protein corona to create synthetic organic hydrogel polymer NPs with high affinity and specificity to peptide toxins, enzymes, and other functional proteins, as well as to specific domains of large proteins. In addition, many NIPAm NPs undergo a change in morphology as a function of temperature. This transformation often correlates with a significant change in NP-biomacromolecule affinity, resulting in a temperature-dependent protein corona. This temperature dependence has been used to develop NP hydrogels with autonomous affinity switching for the protection of proteins from thermal stress and as a method of biomacromolecule purification through a selective thermally induced catch and release. In addition to temperature, changes in pH or buffer can also alter a NP protein corona composition, a property that has been exploited for protein purification. Finally, synthetic polymer nanoparticles with low nanomolar affinity for a peptide toxin were shown to capture and neutralize the toxin in the bloodstream of living mice. While the development of synthetic polymer alternatives to protein affinity reagents is

  9. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim......The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  10. Methane capture from livestock manure.

    Science.gov (United States)

    Tauseef, S M; Premalatha, M; Abbasi, Tasneem; Abbasi, S A

    2013-03-15

    It has been estimated that livestock manure contributes about 240 million metric tons of carbon dioxide equivalent of methane to the atmosphere and represents one of the biggest anthropogenic sources of methane. Considering that methane is the second biggest contributor to global warming after carbon dioxide, it is imperative that ways and means are developed to capture as much of the anthropogenic methane as possible. There is a major associated advantage of methane capture: its use as a source of energy which is comparable in 'cleanness' to natural gas. The present review dwells upon the traditional ways of methane capture used in India, China, and other developing countries for providing energy to the rural poor. It then reviews the present status of methane capture from livestock manure in developed countries and touches upon the prevalent trends.

  11. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to recover sulfur compounds from lunar soil using sorbents derived primarily from in-situ resources....

  12. Capture-stabilize approach for membrane protein SPR assays.

    Science.gov (United States)

    Chu, Ruiyin; Reczek, David; Brondyk, William

    2014-12-08

    Measuring the binding kinetics of antibodies to intact membrane proteins by surface plasmon resonance has been challenging largely because of the inherent difficulties in capturing membrane proteins on chip surfaces while retaining their native conformation. Here we describe a method in which His-tagged CXCR5, a GPCR, was purified and captured on a Biacore chip surface via the affinity tag. The captured receptor protein was then stabilized on the chip surface by limited cross-linking. The resulting chip surface retained ligand binding activity and was used for monoclonal antibody kinetics assays by a standard Biacore kinetics assay method with a simple low pH regeneration step. We demonstrate the advantages of this whole receptor assay when compared to available peptide-based binding assays. We further extended the application of the capture-stabilize approach to virus-like particles and demonstrated its utility analyzing antibodies against CD52, a GPI-anchored protein, in its native membrane environment. The results are the first demonstration of chemically stabilized chip surfaces for membrane protein SPR assays.

  13. Radiative muon capture on hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bertl, W. (Paul Scherrer Inst. (PSI), Villigen (Switzerland)); Ahmad, S.; Chen, C.Q.; Gumplinger, P.; Hasinoff, M.D.; Larabee, A.J.; Sample, D.G.; Schott, W.; Wright, D.H. (British Columbia Univ., Vancouver (Canada)); Armstrong, D.S.; Blecher, M. (Virginia Polytechnic Inst., Blacksburg, VA (United States) Virginia State Univ., Blacksburg, VA (United States)); Azuelos, G. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility Montreal Univ., Quebec (Canada)); Depommier, P.; Jonkmans, G. (Montreal Univ., Quebec (Canada)); Gorringe, T.P. (Kentucky Univ., Lexington, KY (United States)); Henderson, R. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility Melbourne Univ., Parkville (Australia)); Macdonald, J.A.; Poutissou, J.M.; Poutissou, R.; Von Egidy, T.; Zhang, N.S. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility); McDonald, S.C.; Taylor, G.N. (Melbourne Univ., Parkville (Australia)); Robertson, B.D. (Queen' s Univ., Kingston, Ontario (Canada))

    1992-01-01

    The radiative capture of negative muons by protons can be used to measure the weak induced pseudoscalar form factor. Brief arguments why this method is preferable to ordinary muon capture are given followed by a discussion of the experimental difficulties. The solution to these problems as attempted by experiment no. 452 at TRIUMF is presented together with preliminary results from the first run in August 1990. An outlook on the expected final precision and the experimental schedule is also given. (orig.).

  14. Toward transformational carbon capture systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Litynski, John T. [Office of Fossil Energy, U.S. Dept. of Energy, Washington DC (United States); Brickett, Lynn A. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Morreale, Bryan D. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States)

    2015-10-28

    This paper will briefly review the history and current state of Carbon Capture and Storage (CCS) research and development and describe the technical barriers to carbon capture. it will argue forcefully for a new approach to R&D, which leverages both simulation and physical systems at the laboratory and pilot scales to more rapidly move the best technoogies forward, prune less advantageous approaches, and simultaneously develop materials and processes.

  15. The Capture of Jupiter Trojans

    Science.gov (United States)

    Morbidelli, A.; Nesvorny, D.; Vokrouhlicky, D.

    2013-09-01

    The origin of Jupiter Trojans remained mysterious for decades. Particularly, it was difficult to explain the excitation of the inclinations of the Trojan population [1]. In 2005, Morbidelli et al. [2] proposed a scenario of capture from the trans-Neptunian disk, in the framework of the so-called "Nice model" [3,4]. This scenario explained in a natural way the observed orbital distribution of Trojans. The Nice model, however, evolved in the years, in order to satisfy an increasingly large number of constraints. It now appears that the dynamical evolution of the giant planets was different from that envisioned in [2]. Here, we assess again the process of capture of Trojans within this new evolution. We show that (6-8)×10 - 7 of the original trans-Neptunian planetesimals are captured in the Trojan region, with an orbital distribution consistent with the one observed. Relative to [2], the new capture mechanism has the potential of explaining the asymmetry between the L4 and L5 populations. Moreover, the resulting population of Trojans is consistent with that of the Irregular Satellites of Jupiter, which are captured in the same process; a few bodies from the main asteroid belt could also be captured in the Trojan cloud.

  16. Boronic acid lectin affinity chromatography (BLAC). 2. Affinity micropartitioning-mediated comparative glycosylation profiling.

    Science.gov (United States)

    Monzo, Alex; Olajos, Marcell; De Benedictis, Lorenzo; Rivera, Zuly; Bonn, Guenther K; Guttman, András

    2008-09-01

    As a continuation of our work on boronic acid lectin affinity chromatography (BLAC), in this paper we introduce an automated affinity micropartitioning approach using combined boronic acid and concanavalin A (BLAC/Con A) resin-filled micropipette tips to isolate and enrich human serum glycoproteins. The N-linked oligosaccharides of the partitioned glycoproteins were removed by PNGase F enzyme digestion, followed by 8-aminopyrene-1,3,6-trisulfonic acid labeling. Capillary gel electrophoresis with blue LED-induced fluorescence detection was applied in a multiplexed format for comparative glycan profiling. The efficiency of BLAC affinity micropartitioning was compared with that of the individual lectin and pseudolectin affinity enrichment. Finally, we report on our findings in glycosylation differences in human serum samples from healthy and prostate cancer patients by applying BLAC/Con A micropipette tip-based enrichment and comparative multicapillary gel electrophoresis analysis of the released and labeled glycans.

  17. Modulating the selectivity of affinity absorbents to multi-phosphopeptides by a competitive substitution strategy.

    Science.gov (United States)

    Liu, Zheyi; Wang, Fangjun; Chen, Jin; Zhou, Ye; Zou, Hanfa

    2016-08-26

    Although many affinity adsorbents have been developed for phosphopeptides enrichment, high-specifically capturing the multi-phosphopeptides is still a big challenge. Here, we investigated the mechanism of phosphate ion coordination and substitution on affinity adsorbents surfaces and modulated the selectivity of affinity adsorbents to multi-phosphopeptides based on the different capability of mono- and multi-phosphopeptides in competitively substituting the pre-coordinated phosphate ions at strong acidic condition. We demonstrated both the species of pre-coordinated phosphate ions and the substituting conditions played crucial roles in modulating the enrichment selectivity to multi-phosphopeptides, and the pre-coordinated affinity materials with relative more surfaces positive charges exhibited better enrichment efficiency due to the cooperative effect of electrostatic interaction and competitive substitution. Finally, an enrichment selectivity of 85% to multi-phosphopeptides was feasibly achieved with 66% improvement in identification numbers for complex protein sample extracted from HepG2 cells. Data are available via ProteomeXchange with identifier PXD004252.

  18. Mechanically stacked concentrator tandem solar cells

    Science.gov (United States)

    Andreev, V. M.; Rumyantsev, V. D.; Karlina, L. B.; Kazantsev, A. B.; Khvostikov, V. P.; Shvarts, M. Z.; Sorokina, S. V.

    1995-01-01

    Four-terminal mechanically stacked solar cells were developed for advanced space arrays with line-focus reflective concentrators. The top cells are based on AlGaAs/GaAs multilayer heterostructures prepared by low temperature liquid phase epitaxy. The bottom cells are based on heteroepitaxial InP/InGaAs liquid phase epitaxy or on homo-junction GaSb, Zn-diffused structures. The sum of the highest reached efficiencies of the top and bottom cells is 29.4 percent. The best four-terminal tandems have an efficiency of 27 to 28 percent. Solar cells were irradiated with 1 MeV electrons and their performances were determined as a function of fluence up to 10(exp 16) cm(exp-2). It was shown that the radiation resistance of developed tandem cells is similar to the most radiative stable AlGaAs/GaAs cells with a thin p-GaAs photoactive layer.

  19. Cold Climate Heat Pumps Using Tandem Compressors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2016-01-01

    In cold climate zones, e.g. ASHRAE climate regions IV and V, conventional electric air-source heat pumps (ASHP) do not work well, due to high compressor discharge temperatures, large pressure ratios and inadequate heating capacities at low ambient temperatures. Consequently, significant use of auxiliary strip heating is required to meet the building heating load. We introduce innovative ASHP technologies as part of continuing efforts to eliminate auxiliary strip heat use and maximize heating COP with acceptable cost-effectiveness and reliability. These innovative ASHP were developed using tandem compressors, which are capable of augmenting heating capacity at low temperatures and maintain superior part-load operation efficiency at moderate temperatures. Two options of tandem compressors were studied; the first employs two identical, single-speed compressors, and the second employs two identical, vapor-injection compressors. The investigations were based on system modeling and laboratory evaluation. Both designs have successfully met the performance criteria. Laboratory evaluation showed that the tandem, single-speed compressor ASHP system is able to achieve heating COP = 4.2 at 47 F (8.3 C), COP = 2.9 at 17 F (-8.3 C), and 76% rated capacity and COP = 1.9 at -13 F (-25 C). This yields a HSPF = 11.0 (per AHRI 210/240). The tandem, vapor-injection ASHP is able to reach heating COP = 4.4 at 47 F, COP = 3.1 at 17 F, and 88% rated capacity and COP = 2.0 at -13 F. This yields a HSPF = 12.0. The system modeling and further laboratory evaluation are presented in the paper.

  20. Local structure of self-affine sets

    CERN Document Server

    Bandt, Christoph

    2011-01-01

    The structure of a self-similar set with open set condition does not change under magnification. For self-affine sets the situation is completely different. We consider planar self-affine Cantor sets E of the type studied by Bedford, McMullen, Gatzouras and Lalley, for which the projection onto the horizontal axis is an interval. We show that within small square neighborhoods of almost each point x in E, with respect to many product measures on address space, E is well approximated by product sets of an interval and a Cantor set. Even though E is totally disconnected, the limit sets have the product structure with interval fibres, reminiscent to the view of attractors of chaotic differentiable dynamical systems.

  1. Introduction of structural affinity handles as a tool in selective nucleic acid separations

    Science.gov (United States)

    Willson, III, Richard Coale (Inventor); Cano, Luis Antonio (Inventor)

    2011-01-01

    The method is used for separating nucleic acids and other similar constructs. It involves selective introduction, enhancement, or stabilization of affinity handles such as single-strandedness in the undesired (or desired) nucleic acids as compared to the usual structure (e.g., double-strandedness) of the desired (or undesired) nucleic acids. The undesired (or desired) nucleic acids are separated from the desired (or undesired) nucleic acids due to capture by methods including but not limited to immobilized metal affinity chromatography, immobilized single-stranded DNA binding (SSB) protein, and immobilized oligonucleotides. The invention is useful to: remove contaminating genomic DNA from plasmid DNA; remove genomic DNA from plasmids, BACs, and similar constructs; selectively separate oligonucleotides and similar DNA fragments from their partner strands; purification of aptamers, (deoxy)-ribozymes and other highly structured nucleic acids; Separation of restriction fragments without using agarose gels; manufacture recombinant Taq polymerase or similar products that are sensitive to host genomic DNA contamination; and other applications.

  2. Real-time affine invariant gesture recognition for LED smart lighting control

    Science.gov (United States)

    Chen, Xu; Liao, Miao; Feng, Xiao-Fan

    2015-03-01

    Gesture recognition has attracted extensive research interest in the field of human computer interaction. Realtime affine invariant gesture recognition is an important and challenging problem. This paper presents a robust affine view invariant gesture recognition system for realtime LED smart light control. As far as we know, this is the first time that gesture recognition has been applied for control LED smart light in realtime. Employing skin detection, hand blobs captured from a top view camera are first localized and aligned. Subsequently, SVM classifiers trained on HOG features and robust shape features are then utilized for gesture recognition. By accurately recognizing two types of gestures ("gesture 8" and a "5 finger gesture"), a user is enabled to toggle lighting on/off efficiently and control light intensity on a continuous scale. In each case, gesture recognition is rotation- and translation-invariant. Extensive evaluations in an office setting demonstrate the effectiveness and robustness of the proposed gesture recognition algorithm.

  3. Target identification of natural products and bioactive compounds using affinity-based probes.

    Science.gov (United States)

    Pan, Sijun; Zhang, Hailong; Wang, Chenyu; Yao, Samantha C L; Yao, Shao Q

    2016-05-04

    Covering: 2010 to 2014.Advances in isolation, synthesis and screening strategies have made many bioactive substances available. However, in most cases their putative biological targets remain unknown. Herein, we highlight recent advances in target identification of natural products and bioactive compounds by using affinity-based probes. Aided by photoaffinity labelling, this strategy can capture potential cellular targets (on and off) of a natural product or bioactive compound in live cells directly, even when the compound-target interaction is reversible with moderate affinity. The knowledge of these targets may help uncover molecular pathways and new therapeutics for currently untreatable diseases. In this highlight, we will introduce the development of various photoactivatable groups, their synthesis and applications in target identification of natural products and bioactive compounds, with a focus on work done in recent years and from our laboratory. We will further discuss the strengths and weaknesses of each group and the outlooks for this novel proteome-wide profiling strategy.

  4. TandEM: Titan and Enceladus mission

    Science.gov (United States)

    Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C.D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa,

    2009-01-01

    TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfi??re) and possibly several landing probes to be delivered through the atmosphere. ?? Springer Science + Business Media B.V. 2008.

  5. Thermodynamics. Using Affinities to define reversible processes

    CERN Document Server

    Ritacco, Hernán A

    2016-01-01

    In this article a definition of reversible processes in terms of differences in intensive Thermodynamics properties (Affinities) is proposed. This definition makes it possible to both define reversible processes before introducing the concept of entropy and avoid the circularity problem that follows from the Clausius definition of entropy changes. The convenience of this new definition compared to those commonly found in textbooks is demonstrated with examples.

  6. Couplings in Affine Toda Field Theories

    OpenAIRE

    1992-01-01

    We present a systematic derivation for a general formula for the n-point coupling constant valid for affine Toda theories related to any simple Lie algebra {\\bf g}. All n-point couplings with $n \\geq 4$ are completely determined in terms of the masses and the three-point couplings. A general fusing rule, formulated in the root space of the Lie algebra, is derived for all n-point couplings.

  7. Mepanipyrim haptens and antibodies with nanomolar affinity

    OpenAIRE

    Esteve Turrillas, Francesc Albert; Mercader Badia, Josep Vicent; Agulló, Consuelo; Abad Somovilla, Antonio; Abad Fuentes, Antonio

    2013-01-01

    Mepanipyrim is an anilinopyrimidine fungicide used worldwide for crop protection. With the aim of developing useful immunoreagents for mepanipyrim immunoanalysis, two new functionalized derivatives were prepared and antibodies were generated. Affinity and specificity were assessed by direct and indirect competitive ELISA using homologous and heterologous conjugates. Although all antibodies were selective for the target analyte, the immunizing hapten structure was revealed as a determinant for...

  8. Folding defect affine Toda field theories

    CERN Document Server

    Robertson, C

    2013-01-01

    A folding process is applied to fused a^(1)_r defects to construct defects for the non-simply laced affi?ne Toda ?field theories of c^(1)_n, d^(2)_n and a^(2)_n at the classical level. Support for the hypothesis that these defects are integrable in the folded theories is provided by the observation that transmitted solitons retain their form. Further support is given by the demonstration that energy and momentum are conserved.

  9. AFFINE TRANSFORMATION IN RANDOM ITERATED FUNCTION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    熊勇; 史定华

    2001-01-01

    Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, that the figure reconstructed by the new random IFS is the image of the origin figure reconstructed by old IFS under a given affine transformation. Two particular examples are used to show this approach.

  10. On constructing purely affine theories with matter

    Science.gov (United States)

    Cervantes-Cota, Jorge L.; Liebscher, D.-E.

    2016-08-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  11. On constructing purely affine theories with matter

    CERN Document Server

    Cervantes-Cota, Jorge L

    2016-01-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schroedinger's purely affine theory [21], where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  12. Overview of affinity biosensors in food analysis.

    Science.gov (United States)

    Patel, Pradip D

    2006-01-01

    The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field.

  13. Computational Model Reveals Limited Correlation between Germinal Center B-Cell Subclone Abundancy and Affinity: Implications for Repertoire Sequencing

    Science.gov (United States)

    Reshetova, Polina; van Schaik, Barbera D. C.; Klarenbeek, Paul L.; Doorenspleet, Marieke E.; Esveldt, Rebecca E. E.; Tak, Paul-Peter; Guikema, Jeroen E. J.; de Vries, Niek; van Kampen, Antoine H. C.

    2017-01-01

    Immunoglobulin repertoire sequencing has successfully been applied to identify expanded antigen-activated B-cell clones that play a role in the pathogenesis of immune disorders. One challenge is the selection of the Ag-specific B cells from the measured repertoire for downstream analyses. A general feature of an immune response is the expansion of specific clones resulting in a set of subclones with common ancestry varying in abundance and in the number of acquired somatic mutations. The expanded subclones are expected to have BCR affinities for the Ag higher than the affinities of the naive B cells in the background population. For these reasons, several groups successfully proceeded or suggested selecting highly abundant subclones from the repertoire to obtain the Ag-specific B cells. Given the nature of affinity maturation one would expect that abundant subclones are of high affinity but since repertoire sequencing only provides information about abundancies, this can only be verified with additional experiments, which are very labor intensive. Moreover, this would also require knowledge of the Ag, which is often not available for clinical samples. Consequently, in general we do not know if the selected highly abundant subclone(s) are also the high(est) affinity subclones. Such knowledge would likely improve the selection of relevant subclones for further characterization and Ag screening. Therefore, to gain insight in the relation between subclone abundancy and affinity, we developed a computational model that simulates affinity maturation in a single GC while tracking individual subclones in terms of abundancy and affinity. We show that the model correctly captures the overall GC dynamics, and that the amount of expansion is qualitatively comparable to expansion observed from B cells isolated from human lymph nodes. Analysis of the fraction of high- and low-affinity subclones among the unexpanded and expanded subclones reveals a limited correlation between

  14. Experimental investigation of streamer affinity for dielectric surfaces

    NARCIS (Netherlands)

    Trienekens, D.J.M.; Nijdam, S.; Akkermans, G.; Plompen, I.; Christen, T.; Ebert, U.

    2015-01-01

    We have experimentally investigated the affinity of streamers for dielectric surfaces using stroboscopic imaging and stereo photography. Affinity of streamers for dielectric surfaces was found to depend on a wide set of parameters, including pressure, voltage, dielectric material and di

  15. Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of o-Carbonyl Carbazolequinone Derivatives

    Science.gov (United States)

    Martínez-Cifuentes, Maximiliano; Clavijo-Allancan, Graciela; Zuñiga-Hormazabal, Pamela; Aranda, Braulio; Barriga, Andrés; Weiss-López, Boris; Araya-Maturana, Ramiro

    2016-01-01

    A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules. PMID:27399676

  16. Spatial model of affinity maturation in germinal centers

    NARCIS (Netherlands)

    Kesmir, C.; Boer, R.J. de

    2003-01-01

    Affinity maturation of humoral responses to T-cell-dependent antigens occurs in germinal centers (GC). In GCs antigen-specific B cells undergo rounds of somatic mutations that alter their affinity. High-affinity mutants take over GCs very soon after they appear; the replacement rate is as high as 4

  17. Affine Structures on a Ringed Space and Schemes

    Institute of Scientific and Technical Information of China (English)

    Fengwen AN

    2011-01-01

    The author first introduces the notion of affine structures on a ringed space and then obtains several related properties. Affine structures on a ringed space, arising from complex analytical spaces of algebraic schenes, behave like differential structures on a smooth nanifold.As one does for differential manifolds, pseudogroups of affine transformations are used to define affine atlases on a ringed space. An atlas on a space is said to be an affine structure if it is maximal. An affine structure is said to be admissible if there is a sheaf on the underlying space such that they are coincide on all affine charts, which are in deed affine open sets of a scheme. In a rigour manner, a scheme is defined to be a ringed space with a specified affine structure if the affine structures make a contribution to the cases such as analytical spaces of algebraic schemes. Particularly, by the whole of affine structures on a pace, two necessary and sufficient conditions, that two spaces are homeomorphic and that two schemes are isomorphic, coming from the main theorems of the paper, are obtained respectively. A conclusion is drawn that the whole of affine structures on a space and a scheme, as local data, encode and reflect the global properties of the space and the scheme,respectively.

  18. Glycation of the high affinity NGF-receptor and RAGE leads to reduced ligand affinity.

    Science.gov (United States)

    Bennmann, Dorit; Kannicht, Christoph; Fisseau, Claudine; Jacobs, Kathleen; Navarette-Santos, Alexander; Hofmann, Britt; Horstkorte, Rüdiger

    2015-09-01

    AGEs are posttranslational modifications generated by irreversible non-enzymatic crosslinking reactions between sugars and proteins - a reaction referred to as glycation. Glycation, a feature of ageing, can lead to non-degradable and less functional proteins and enzymes and can additionally induce inflammation and further pathophysiological processes such as neurodegeneration. In this study we investigated the influence of glycation on the high affinity NGF-receptor TrkA and the AGE-receptor RAGE. We quantified the binding affinity of the TrkA-receptor and RAGE to their ligands by surface plasmon resonance (SPR) and compared these to the binding affinity after glycation. At the same time, we established a glycation procedure using SPR. We found that glycation of TrkA reduced the affinity to NGF by a factor of three, which could be shown to lead to a reduction of NGF-dependent neurite outgrowth in PC12 cells. Glycation of RAGE reduced binding affinity of AGEs by 10-fold.

  19. Uniform Orientation of Biotinylated Nanobody as an Affinity Binder for Detection of Bacillus thuringiensis (Bt) Cry1Ac Toxin

    Science.gov (United States)

    Li, Min; Zhu, Min; Zhang, Cunzheng; Liu, Xianjin; Wan, Yakun

    2014-01-01

    Nanobodies are the smallest natural fragments with useful properties such as high affinity, distinct paratope and high stability, which make them an ideal tool for detecting target antigens. In this study, we generated and characterized nanobodies against the Cry1Ac toxin and applied them in a biotin-streptavidin based double antibodies (nanobodies) sandwich-ELISA (DAS-ELISA) assay. After immunizing a camel with soluble Cry1Ac toxin, a phage displayed library was constructed to generate Nbs against the Cry1Ac toxin. Through successive rounds of affinity bio-panning, four nanobodies with greatest diversity in CDR3 sequences were obtained. After affinity determination and conjugating to HRP, two nanobodies with high affinity which can recognize different epitopes of the same antigen (Cry1Ac) were selected as capture antibody (Nb61) and detection antibody (Nb44). The capture antibody (Nb61) was biotinylated in vivo for directional immobilization on wells coated with streptavidin matrix. Both results of specificity analysis and thermal stability determination add support for reliability of the following DAS-ELISA with a minimum detection limit of 0.005 μg·mL−1 and a working range 0.010–1.0 μg·mL−1. The linear curve displayed an acceptable correlation coefficient of 0.9976. These results indicated promising applications of nanobodies for detection of Cry1Ac toxin with biotin-streptavidin based DAS-ELISA system. PMID:25474492

  20. Uniform Orientation of Biotinylated Nanobody as an Affinity Binder for Detection of Bacillus thuringiensis (Bt Cry1Ac Toxin

    Directory of Open Access Journals (Sweden)

    Min Li

    2014-12-01

    Full Text Available Nanobodies are the smallest natural fragments with useful properties such as high affinity, distinct paratope and high stability, which make them an ideal tool for detecting target antigens. In this study, we generated and characterized nanobodies against the Cry1Ac toxin and applied them in a biotin-streptavidin based double antibodies (nanobodies sandwich-ELISA (DAS-ELISA assay. After immunizing a camel with soluble Cry1Ac toxin, a phage displayed library was constructed to generate Nbs against the Cry1Ac toxin. Through successive rounds of affinity bio-panning, four nanobodies with greatest diversity in CDR3 sequences were obtained. After affinity determination and conjugating to HRP, two nanobodies with high affinity which can recognize different epitopes of the same antigen (Cry1Ac were selected as capture antibody (Nb61 and detection antibody (Nb44. The capture antibody (Nb61 was biotinylated in vivo for directional immobilization on wells coated with streptavidin matrix. Both results of specificity analysis and thermal stability determination add support for reliability of the following DAS-ELISA with a minimum detection limit of 0.005 μg·mL−1 and a working range 0.010–1.0 μg·mL−1. The linear curve displayed an acceptable correlation coefficient of 0.9976. These results indicated promising applications of nanobodies for detection of Cry1Ac toxin with biotin-streptavidin based DAS-ELISA system.

  1. Optic capture pars plana lensectomy

    Directory of Open Access Journals (Sweden)

    Lee JE

    2012-10-01

    Full Text Available Joo Eun LeeDepartment of Ophthalmology, Inje University College of Medicine, Busan, South KoreaObjective: To describe an optic capture pars plana lensectomy technique.Methods: After core vitrectomy, pars plana lensectomy is performed with preservation of the anterior capsule. Capsulorhexis is performed on the preserved anterior capsule through a 2.8 mm clear corneal incision. An intraocular lens (IOL is placed in the ciliary sulcus, and then the optic of the IOL is pushed back to the vitreous cavity so that the optic is captured by the surrounding capsulorhexis margin.Results: The captured IOL-capsule diaphragm remained stable during air–fluid exchange and prevented air prolapse to the anterior chamber. IOL stability and a clear visual axis were preserved during the follow-up period.Conclusion: With this modified pars plana lensectomy technique, stable IOL position and clear visual axis can be maintained when a pars plana approach is needed during combined cataract and vitreoretinal surgery.Keywords: lensectomy, optic capture, pars plana lensectomy, vitrectomy

  2. A dual-tagging system for the affinity purification of mammalian protein complexes

    Energy Technology Data Exchange (ETDEWEB)

    Giannone, Richard J [ORNL; McDonald, W Hayes [ORNL; Hurst, Gregory {Greg} B [ORNL; Huang, Ying [ORNL; Wu, Jun [ORNL; Liu, Yie [National Institute on Aging, Baltimore; Wang, Yisong [ORNL

    2007-01-01

    One popular method to elucidate protein-protein interactions involves the native co-purification of an affinity tagged protein and its interacting partners, which are subsequently identified through mass spectrometry (MS) (1). Although straightforward, reproducible, and broadly employed, this strategy is hampered by the efficacy of protein recoveries both in terms of sensitivity and specificity. This is especially pertinent to methodologies that employ a single-step of purification, where suboptimal enrichment of the bait protein and its partners over background can lead to masking of their signals. Although improvements to MS instrumentation generally increase peptide detection sensitivities, the problem of specificity, i.e. distinguishing specific from non-specific interacting proteins, remains. Thus ultimately, the limiting factor in the identification of specific interacting proteins lies with the purification itself. An effort to resolve this specificity issue has been made with the introduction of the Tandem Affinity Purification (TAP) tag. This construct consists of an IgG-binding domain and calmodulin binding peptide domain separated by a tobacco etch virus (TEV) protease cleavage site (2). The TAP method was originally developed in yeast and has best demonstrated its utility in the systematic identification of numerous multiprotein complexes in the yeast proteome (3). Although modifications to the original TAP have been successful in examining the protein networks of mammalian cells (4-7), the strategy offers a relatively low yield of bait and specific interacting proteins (8), and the success rate are usually on case-by-case basis. In addition, problems inherent to any protein tagging strategy remain, such as variable exposure of the affinity tag, disruption of the bait protein's ability to fold properly, steric exclusion of interacting partners, and/or ectopic overexpression of the fusion protein, which can lead to complications in both the

  3. Metric-affine gravitation theory and superpotentials

    Energy Technology Data Exchange (ETDEWEB)

    Giachetta, G.; Mangiarotti, L.; Saltarelli, A. [Camerino, Univ. (Italy). Dipt. di Matematica e Fisica

    1997-05-01

    They consider a metric-affine theory of gravity in which the dynamical fields are the Lorentzian metrics and the non-symmetric linear connections on the worked manifold X. Working with a Lagrangian density which is invariant under general covariant transformations and using standard tools of the calculus of variations, they study the corresponding currents. They find that the superpotential takes a nice form involving the torsion of the linear connection in a simple way and generalizing the well-known Komar superpotential. A feature of our approach is the use of the Poincare`-Cartan form in relation to the first variational formula of the calculus of variations.

  4. Affinity chromatography with an immobilized RNA enzyme.

    OpenAIRE

    Vioque, A; Altman, S

    1986-01-01

    M1 RNA, the catalytic subunit of Escherichia coli RNase P, has been covalently linked at its 3' terminus to agarose beads. Unlike M1 RNA, which is active in solution in the absence of the protein component (C5) of RNase P, the RNA linked to the beads is active only in the presence of C5 protein. Affinity chromatography of crude extracts of E. coli on a column prepared from the beads to which the RNA has been crosslinked results in the purification of C5 protein in a single step. The protein h...

  5. Analysis of affinely equivalent Boolean functions

    Institute of Scientific and Technical Information of China (English)

    MENG QingShu; ZHANG HuanGuo; YANG Min; WANG ZhangYi

    2007-01-01

    By some basic transforms and invariant theory, we give two results: 1) an algorithm,which can be used to judge if two Boolean functions are affinely equivalent and to obtain the equivalence relationship if they are equivalent. This is useful in studying Boolean functions and in engineering. For example, we classify all 8-variable homogeneous bent functions of degree 3 into two classes; 2) Reed-Muller codes R(4,6)/R(1,6), R(3,7)/R(1,7) are classified efficiently.

  6. Affine Coherent States in Quantum Cosmology

    CERN Document Server

    Malkiewicz, Przemyslaw

    2015-01-01

    A brief summary of the application of coherent states in the examination of quantum dynamics of cosmological models is given. We discuss quantization maps, phase space probability distributions and semiclassical phase spaces. The implementation of coherent states based on the affine group resolves the hardest singularities, renders self-adjoint Hamiltonians without boundary conditions and provides a completely consistent semi-classical description of the involved quantum dynamics. We consider three examples: the closed Friedmann model, the anisotropic Bianchi Type I model and the deep quantum domain of the Bianchi Type IX model.

  7. Latest European coelacanth shows Gondwanan affinities.

    Science.gov (United States)

    Cavin, Lionel; Forey, Peter L; Buffetaut, Eric; Tong, Haiyan

    2005-06-22

    The last European fossil occurrence of a coelacanth is from the Mid-Cretaceous of the English Chalk (Turonian, 90 million years ago). Here, we report the discovery of a coelacanth from Late Cretaceous non-marine rocks in southern France. It consists of a left angular bone showing structures that imply close phylogenetic affinities with some extinct Mawsoniidae. The closest relatives are otherwise known from Cretaceous continental deposits of southern continents and suggest that the dispersal of freshwater organisms from Africa to Europe occurred in the Late Cretaceous.

  8. Flexible and fragmentable tandem photosensitive nanocrystal skins

    Science.gov (United States)

    Akhavan, S.; Uran, C.; Bozok, B.; Gungor, K.; Kelestemur, Y.; Lesnyak, V.; Gaponik, N.; Eychmüller, A.; Demir, H. V.

    2016-02-01

    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm-2 at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion.We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of

  9. Multilaboratory validation of a method to confirm chloramphenicol in shrimp and crabmeat by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Hammack, Walter; Carson, Mary C; Neuhaus, Barbara K; Hurlbut, Jeffrey A; Nochetto, Cristina; Stuart, James S; Brown, Amy; Kilpatrick, Donna; Youngs, Kristl; Ferbos, Krystle; Heller, David N

    2003-01-01

    An existing method for chloramphenicol (CAP) determination in shrimp using a gas chromatograph with electron capture detector was adapted for confirmation of CAP with a liquid chromatograph interfaced to a triple quadrupole mass spectrometer. CAP residues are extracted from tissue with ethyl acetate, isolated via liquid-liquid extraction, and concentrated by evaporation. Extracts are chromatographed by using a reversed-phased column and analyzed by electrospray negative mode tandem mass spectrometry. Four product ions (m/z 152, 176, 194, and 257) of precursor m/z 321 were monitored. Moving from gas chromatography to liquid chromatography-tandem mass spectrometry improved the sensitivity of the method greatly, enabling reliable confirmation of CAP residues at 0.3 microg/kg (ppb). The method meets confirmation criteria recommended by the U.S. Food and Drug Administration and 4-point identification criteria established by the European Union. With slight modifications to accommodate different equipment, the method was validated in 3 laboratories.

  10. Affine Fullerene C60 in a GS-Quasigroup

    Directory of Open Access Journals (Sweden)

    Vladimir Volenec

    2014-01-01

    Full Text Available It will be shown that the affine fullerene C60, which is defined as an affine image of buckminsterfullerene C60, can be obtained only by means of the golden section. The concept of the affine fullerene C60 will be constructed in a general GS-quasigroup using the statements about the relationships between affine regular pentagons and affine regular hexagons. The geometrical interpretation of all discovered relations in a general GS-quasigroup will be given in the GS-quasigroup C(1/2(1+5.

  11. 49 CFR 563.9 - Data capture.

    Science.gov (United States)

    2010-10-01

    ... frontal or side air bag deployment crash, capture and record the current deployment data, up to two events... 49 Transportation 6 2010-10-01 2010-10-01 false Data capture. 563.9 Section 563.9 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.9 Data capture. The EDR must capture and record...

  12. Tandem robot control system and method for controlling mobile robots in tandem

    Energy Technology Data Exchange (ETDEWEB)

    Hayward, David R. (Albuquerque, NM); Buttz, James H. (Albuquerque, NM); Shirey, David L. (Albuquerque, NM)

    2002-01-01

    A control system for controlling mobile robots provides a way to control mobile robots, connected in tandem with coupling devices, to navigate across difficult terrain or in closed spaces. The mobile robots can be controlled cooperatively as a coupled system in linked mode or controlled individually as separate robots.

  13. A Hybrid Approach To Tandem Cylinder Noise

    Science.gov (United States)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  14. Method of fabricating bifacial tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wojtczuk, Steven J; Chiu, Philip T; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2014-10-07

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  15. HRIBF Tandem Accelerator Radiation Safety System Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Blankenship, J.L.; Juras, R.C.

    1998-11-04

    The HRIBF Tandem Accelerator Radiation Safety System was designed to permit experimenters and operations staff controlled access to beam transport and experiment areas with accelerated beam present. Neutron-Gamma detectors are mounted in eaeh area at points of maximum dose rate and the resulting signals are integrated by redundan~ circuitry; beam is stopped if dose rate or integrated dose exceeds established limits. This paper will describe the system, in use for several vears at the HRIBF, and discuss changes recently made to modernize the system and to make the system compliant with DOE Order 5480.25 and related ORNL updated safety rules.

  16. Extraction of haemoglobin from human blood by affinity precipitation using a haptoglobin-based stimuli-responsive affinity macroligand.

    Science.gov (United States)

    Stocker-Majd, Gisela; Hilbrig, Frank; Freitag, Ruth

    2008-06-13

    Affinity precipitation was compared to affinity chromatography and batch adsorption as the final purification step in a protocol for the isolation of haemoglobin from human blood. Haptoglobin was the affinity ligand. The first steps on the process were realized by traditional methods (lyses of red blood cells followed by ammonium sulphate precipitation). For affinity chromatography (and batch adsorption) the ligand was linked to Sepharose, for affinity precipitation to a thermoresponsive polymer, namely poly(N-isopropylacrylamide). Five haptoglobin-poly(N-isopropylacrylamide) bioconjugates (affinity macroligands) were constructed with different polymer: haptoglobin-coupling ratios. Conjugation of haptoglobin to the soluble poly(N-isopropylacrylamide) apparently does not change the interaction thermodynamics with haemoglobin, as the haemoglobin binding constants calculated by a Scatchard analysis for the affinity macroligand were of the same order of magnitude as those described in the literature for the haemoglobin-haptoglobin complex in solution. Two elution protocols were used for haemoglobin release from the various affinity materials, one at pH 2, the other with 5 M urea at pH 11. Both affinity chromatography and affinity precipitation yielded a pure haemoglobin of high quality. Compared to the affinity chromatography, affinity precipitation showed a significantly higher ligand efficiency (ratio of the experimental capacity to the theoretical one). The method thus makes better use of the expensive affinity ligands. As affinity precipitation only requires small temperature changes to bring about precipitation/redissolution of the affinity complexes and a centrifugation step for recovery of the precipitate, the method in addition has advantages in term of scalability and simplicity.

  17. Spherical functions on affine Lie groups

    CERN Document Server

    Etingof, P; Kirillov, A A; Pavel Etingof; Igor Frenkel; Alexander Kirillov Jr

    1994-01-01

    We show that the space of holomorphic functions of a fixed degree on an affine Lie group which take values in a finite-dimensional representation of this group and are equivariant with respect to (twisted) conjugacy coin- cides with the space of conformal blocks of the Wess-Zumino-Witten conformal field theory on an elliptic curve with punctures, or, equivalently,with the space of states of the Chern-Simons topological field theory in genus 1. This provides a group-theoretic realization of the Segal modular functor for elliptic curves. We also show that the the radial part of the second order Laplace operator on an affine Lie group acting in the space of equivariant functions coincides with the operator defining the Knizhnik-Zamolodchikov connection on conformal blocks on elliptic curves, and its eigenfunctions coincide with the correlation functions of conformal blocks. At the critical value of the degree (minus the dual Coxeter number of the underlying simple Lie algebra) there exist higher order Laplace op...

  18. Affine Mirkovi\\'c-Vilonen polytopes

    CERN Document Server

    Baumann, Pierre; Tingley, Peter

    2011-01-01

    Each integrable lowest weight representation of a symmetrizable Kac-Moody Lie algebra g has a crystal in the sense of Kashiwara, which describes its combinatorial properties. For a given g, there is a limit crystal, usually denoted by B(-\\infty), which contains all the other crystals. When g is finite dimensional, a convex polytope, called the Mirkovi\\'c-Vilonen polytope, can be associated to each element in B(-\\infty). This polytope sits in the dual space of a Cartan subalgebra of g, and its edges are parallel to the roots of g. In this paper, we generalize this construction to the case where g is a symmetric affine Kac-Moody algebra. The datum of the polytope must however be complemented by partitions attached to the edges parallel to the imaginary root \\delta. We prove that these decorated polytopes are characterized by conditions on their normal fans and on their 2-faces. In addition, we discuss how our polytopes provide an analog of the notion of Lusztig datum for affine Kac-Moody algebras. Our main tool...

  19. Affine conformal vectors in space-time

    Science.gov (United States)

    Coley, A. A.; Tupper, B. O. J.

    1992-05-01

    All space-times admitting a proper affine conformal vector (ACV) are found. By using a theorem of Hall and da Costa, it is shown that such space-times either (i) admit a covariantly constant vector (timelike, spacelike, or null) and the ACV is the sum of a proper affine vector and a conformal Killing vector or (ii) the space-time is 2+2 decomposable, in which case it is shown that no ACV can exist (unless the space-time decomposes further). Furthermore, it is proved that all space-times admitting an ACV and a null covariantly constant vector (which are necessarily generalized pp-wave space-times) must have Ricci tensor of Segré type {2,(1,1)}. It follows that, among space-times admitting proper ACV, the Einstein static universe is the only perfect fluid space-time, there are no non-null Einstein-Maxwell space-times, and only the pp-wave space-times are representative of null Einstein-Maxwell solutions. Otherwise, the space-times can represent anisotropic fluids and viscous heat-conducting fluids, but only with restricted equations of state in each case.

  20. Cyclage, catabolism, and the affine Hecke algebra

    CERN Document Server

    Blasiak, Jonah

    2010-01-01

    We identify a subalgebra \\pH_n of the extended affine Hecke algebra \\eH_n of type A. The subalgebra \\pH_n is a \\u-analogue of the monoid algebra of \\S_n \\ltimes \\ZZ_{\\geq 0}^n and inherits a canonical basis from that of \\eH_n. We show that its left cells are naturally labeled by tableaux filled with positive integer entries having distinct residues mod n, which we term \\emph{positive affine tableaux} (PAT). We then exhibit a cellular subquotient \\R_{1^n} of \\pH_n that is a \\u-analogue of the ring of coinvariants \\CC[y_1,...,y_n]/(e_1,...,e_n) with left cells labeled by PAT that are essentially standard Young tableaux with cocharge labels. Multiplying canonical basis elements by a certain element \\pi \\in \\pH_n corresponds to rotations of words, and on cells corresponds to cocyclage. We further show that \\R_{1^n} has cellular quotients \\R_\\lambda that are \\u-analogues of the Garsia-Procesi modules R_\\lambda with left cells labeled by (a PAT version of) the \\lambda-catabolizable tableaux. We give a conjectural d...

  1. Preparation and characterization of polysulfone affinity membranes bearing a synthetic peptide ligand for the separation of murine immunoglobulins.

    Science.gov (United States)

    Boi, Cristiana; Algeri, Cristian; Sarti, Giulio C

    2008-01-01

    Affinity membranes have been prepared by immobilizing D-PAM, a synthetic ligand that exhibits affinity for the Fc portion of antibodies, onto poliethersulfone microporous membranes. The ligand density has been measured and the ligand utilization was evaluated and compared with literature data available for chromatographic beads. The resulting new affinity membranes have been experimentally characterized and tested by using pure murine IgG solutions and mouse serum. Equilibrium and kinetic parameters have been obtained in batch experiments using pure protein solutions. The highest binding capacity measured for murine IgG was 45 microg/cm(2) obtained at 1.2 mg/mL protein concentration at equilibrium, while the maximum static binding capacity calculated with the Langmuir model was 81 microg/cm(2). The adsorption of murine IgG on the affinity membranes was described using different isotherms: Freundlich and Temkin models have been considered and critically compared with the Langmuir adsorption model. A dynamic binding capacity of 21 microg/cm(2) was obtained by feeding a solution of 0.3 mg/mL of murine IgG, confirming the results obtained in batch experiments at the same concentration. The affinity membranes considered are endowed with good binding capacity for murine IgG and good selectivity for immunoglobulins and can be considered for the capturing step of an antibody production process.

  2. Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

    Science.gov (United States)

    Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

    2016-08-26

    Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach.

  3. Interpretation of tandem mass spectra of posttranslationally modified peptides

    DEFF Research Database (Denmark)

    Bunkenborg, J.; Matthiesen, R.

    2013-01-01

    Tandem mass spectrometry provides a sensitive means of analyzing the amino acid sequence of peptides and modified peptides by providing accurate mass measurements of precursor and fragment ions. Modern mass spectrometry instrumentation is capable of rapidly generating many thousands of tandem mas...

  4. Turkish population data on the short tandem repeat locus TPOX

    DEFF Research Database (Denmark)

    Vural, B; Poda, M; Atlioglu, E;

    1998-01-01

    Allele and genotype frequencies were determined for the STR (short tandem repeat) locus TPOX in a random Turkish population sample of 200 individuals.......Allele and genotype frequencies were determined for the STR (short tandem repeat) locus TPOX in a random Turkish population sample of 200 individuals....

  5. Natural materials for carbon capture.

    Energy Technology Data Exchange (ETDEWEB)

    Myshakin, Evgeniy M. (National Energy Technology Laboratory, Pittsburgh, PA); Romanov, Vyacheslav N. (National Energy Technology Laboratory, Pittsburgh, PA); Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  6. Doping Polypyrrole Films with 4-N-Pentylphenylboronic Acid to Enhance Affinity towards Bacteria and Dopamine.

    Science.gov (United States)

    Golabi, Mohsen; Padiolleau, Laurence; Chen, Xi; Jafari, Mohammad Javad; Sheikhzadeh, Elham; Turner, Anthony P F; Jager, Edwin W H; Beni, Valerio

    2016-01-01

    Here we demonstrate the use of a functional dopant as a fast and simple way to tune the chemical affinity and selectivity of polypyrrole films. More specifically, a boronic-functionalised dopant, 4-N-Pentylphenylboronic Acid (PBA), was used to provide to polypyrrole films with enhanced affinity towards diols. In order to prove the proposed concept, two model systems were explored: (i) the capture and the electrochemical detection of dopamine and (ii) the adhesion of bacteria onto surfaces. The chemisensor, based on overoxidised polypyrrole boronic doped film, was shown to have the ability to capture and retain dopamine, thus improving its detection; furthermore the chemisensor showed better sensitivity in comparison with overoxidised perchlorate doped films. The adhesion of bacteria, Deinococcus proteolyticus, Escherichia coli, Streptococcus pneumoniae and Klebsiella pneumoniae, onto the boric doped polypyrrole film was also tested. The presence of the boronic group in the polypyrrole film was shown to favour the adhesion of sugar-rich bacterial cells when compared with a control film (Dodecyl benzenesulfonate (DBS) doped film) with similar morphological and physical properties. The presented single step synthesis approach is simple and fast, does not require the development and synthesis of functional monomers, and can be easily expanded to the electrochemical, and possibly chemical, fabrication of novel functional surfaces and interfaces with inherent pre-defined sensing and chemical properties.

  7. Carbon Capture and Sequestration (CCS)

    Science.gov (United States)

    2009-06-19

    for the pre-combustion capture of CO2 is the use of Integrated Gasification Combined-Cycle ( IGCC ) technology to generate electricity.14 There are...currently four commercial IGCC plants worldwide (two in the United States) each with a capacity of about 250 MW. The technology has yet to make a major... IGCC is an electric generating technology in which pulverized coal is not burned directly but mixed with oxygen and water in a high-pressure gasifier

  8. Affinity mesh screen materials for selective extraction and analysis of antibiotics using transmission mode desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Yang, Samuel H; Wang, Evelyn H; Gurak, John A; Bhawal, Sumit; Deshmukh, Rajendrasing; Wijeratne, Aruna B; Edwards, Brian L; Foss, Frank W; Timmons, Richard B; Schug, Kevin A

    2013-06-25

    The extraction of active compounds from natural sources has shown to be an effective approach to drug discovery. However, the isolation and identification of natural products from complex extracts can be an arduous task. A novel approach to drug discovery is presented through the use of polymer screens functionalized with an l-lysine-d-alanine-d-alanine (Kaa) peptide to create new affinity capture mesh screen materials. The Kaa sequence is a well-characterized specific binding site for antibiotics that inhibit cell wall synthesis in Gram-positive bacteria. The detailed synthesis and characterization of these novel screen materials are presented in this work. Polypropylene mesh screens were first coated with a poly(acrylic acid) film by pulsed plasma polymerization. The synthesized Kaa peptide was then covalently attached to carboxylic acid groups through a condensation reaction. An analysis of captured compounds was performed in a rapid fashion with transmission-mode desorption electrospray ionization (TM-DESI) mass spectrometry. A proof of principle was demonstrated to show the ability of the novel affinity capture materials to select for a macrocyclic antibiotic, vancomycin, over a negative control compound, spectinomycin. With further development, this method may provide a rapid screening technique for new antibacterial compounds, for example, those extracted from natural product sources having a limited supply. Here, we show that the screen can capture vancomycin preferentially over spectinomycin in a spiked extract of tea leaves.

  9. Reactive control of zoom while fixating using perspective and affine cameras.

    Science.gov (United States)

    Tordoff, Ben; Murray, David

    2004-01-01

    This paper describes reactive visual methods of controlling the zoom setting of the lens of an active camera while fixating upon an object. The first method assumes a perspective projection and adjusts zoom to preserve the ratio of focal length to scene depth. The active camera is constrained to rotate, permitting self-calibration from the image motion of points on the static background. A planar structure from motion algorithm is used to recover the depth of the foreground. The foreground-background segmentation exploits the properties of the two different interimage homographies which are observed. The fixation point is updated by transfer via the observed planar structure. The planar method is shown to work on real imagery, but results from simulated data suggest that its extension to general 3D structure is problematical under realistic viewing and noise regimes. The second method assumes an affine projection. It requires no self-calibration and the zooming camera may move generally. Fixation is again updated using transfer, but now via the affine structure recovered by factorization. Analysis of the projection matrices allows the relative scale of the affine bases in different views to be found in a number of ways and, hence, controlled to unity. The various ways are compared and the best used on real imagery captured from an active camera fitted with a controllable zoom lens in both look-move and continuous operation.

  10. Routes to improve binding capacities of affinity resins demonstrated for Protein A chromatography.

    Science.gov (United States)

    Müller, Egbert; Vajda, Judith

    2016-05-15

    Protein A chromatography is a well-established platform in downstream purification of monoclonal antibodies. Dynamic binding capacities are continuously increasing with almost every newly launched Protein A resin. Nevertheless, binding capacities of affinity chromatography resins cannot compete with binding capacities obtained with modern ion exchange media. Capacities of affinity resins are roughly 50% lower. High binding capacities of ion exchange media are supported by spacer technologies. In this article, we review existing spacer technologies of affinity chromatography resins. A yet known effective approach to increase the dynamic binding capacity of Protein A resins is oligomerization of the particular Protein A motifs. This resembles the tentacle technology used in ion exchange chromatography. Dynamic binding capacities of a hexameric ligand are roughly twice as high compared to capacities obtained with a tetrameric ligand. Further capacity increases up to 130mg/ml can be realized with the hexamer ligand, if the sodium phosphate buffer concentration is increased from 20 to 100mM. Equilibrium isotherms revealed a BET shape for the hexamer ligand at monoclonal antibody liquid phase concentrations higher than 9mg/ml. The apparent multilayer formation may be due to hydrophobic forces. Other quality attributes such as recovery, aggregate content, and overall purity of the captured monoclonal antibody are not affected.

  11. Understanding ligand-protein interactions in affinity membrane chromatography for antibody purification.

    Science.gov (United States)

    Boi, Cristiana; Busini, Valentina; Salvalaglio, Matteo; Cavallotti, Carlo; Sarti, Giulio C

    2009-12-11

    Affinity chromatography with Protein A beads has become the conventional unit operation for the primary capture of monoclonal antibodies. However, Protein A activated supports are expensive and ligand leakage is an issue to be considered. In addition, the limited production capabilities of the chromatographic process drive the research towards feasible alternatives. The use of synthetic ligands as Protein A substitutes has been considered in this work. Synthetic ligands, that mimic the interaction between Protein A and the constant fragment (Fc) of immunoglobulins, have been immobilized on cellulosic membrane supports. The resulting affinity membranes have been experimentally characterized with pure immunoglobulin G (IgG). The effects of the membrane support and of the spacer arm on the ligand-ligate interaction have been studied in detail. Experimental data have been compared with molecular dynamic simulations with the aim of better understanding the interaction mechanisms. Molecular dynamic simulations were performed in explicit water, modelling the membrane as a matrix of overlapped glucopyranose units. Electrostatic charges of the ligand and spacer were calculated through ab initio methods to complete the force field used to model the membrane. The simulations enabled to elucidate how the interactions of surface, spacer and ligand with IgG, contribute to the formation of the bond between protein and affinity membrane.

  12. A solution process for inverted tandem solar cells

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Bundgaard, Eva; Sylvester-Hvid, Kristian O.;

    2011-01-01

    or vanadium(V)oxide in the case of inverted tandem cells. It was found that the inverted tandem solar cells performed comparable or better than the normal geometry devices, showing that the connection structure of vanadium(V)oxide, Ag nanoparticles and zinc(II)oxide functions both as a good recombination......Tandem solar cells with normal and inverted device geometries were prepared by a solution process. Both device types were based on the use of zinc(II)oxide as the electron transporting layer (ETL). The hole transporting layer (HTL) was either PEDOT:PSS for normal geometry tandem solar cells...... layer, ensuring serial connection, and as a solvent barrier, protecting the first photoactive layer from processing of the second layer. This successfully demonstrates a tandem solar cell fabrication process fully compatible with state-of-the-art solution based automated production procedures....

  13. Active fragments-guided drug discovery and design of selective tropane alkaloids using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry coupled with virtual calculation and biological evaluation.

    Science.gov (United States)

    Zhou, Mengge; Ma, Xiaoyao; Sun, Jixue; Ding, Guoyu; Cui, Qingxin; Miao, Yan; Hou, Yuanyuan; Jiang, Min; Bai, Gang

    2017-02-01

    Tropane alkaloids (TAs), rich in the plant of Physochlaina infundibularis Kuang, which is named Huashanshen (HSS) in China, showed good effects on types of spasms. However, no data were collected to explore the relationship between the specificity for muscarinic receptor subtypes and the structures of these TAs. To address this issue, an extracted ion chromatogram (EIC) strategy using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) based on the fragmentation behavior of the TA standards was established to rapidly capture the varied TAs from HSS. Based on the provided structural information of diagnostic ions or neutral loss, 29 TAs were efficiently profiled, especially some trace ingredients. In additional, via virtual validation combined with molecular dynamic simulation, approximately a dozen alkaloids were found with high selectivity for muscarinic receptors. In additional, N-acetyl convolicine was chosen for selectivity evaluation of M2 or M3 receptors through the use of a dual-luciferase reporter assay system at the cellular level and an ACh-induced constricted strip test in vitro. After summarizing the active fragments and the structure-activity relationship (SAR) information, a new modified TA that takes advantage of both the high affinity and high selectivity for M3 receptors was proposed and evaluated successfully. This study provided an effective approach for the discovery and design of natural products based on highly selective drugs by UPLC-Q/TOF-MS coupled with virtual calculation and biological evaluation. Graphical Abstract Active fragments-guided strategy for selective inhibitors from HSS.

  14. Dynamic friction of self-affine surfaces

    Science.gov (United States)

    Schmittbuhl, Jean; Vilotte, Jean-Pierre; Roux, Stéphane

    1994-02-01

    We investigate the velocity dependence of the friction between two rigid blocks limited by a self-affine surface such as the one generated by a crack. The upper solid is subjected either to gravity or to an external elastic stiffness, and is driven horizontally at constant velocity, V, while the lower solid is fixed. For low velocities, the apparent friction coefficient is constant. For high velocities, the apparent friction is shown to display a velocity weakening. The weakening can be related to the variation of the mean contact time due to the occurrence of jumps during the motions. The cross-over between these two regimes corresponds to a characteristic velocity which depends on the geometry of the surfaces and on the mean normal force. In the case of simple gravity loading, the velocity dependence of the apparent friction at high velocities is proportional to 1/V^2 where V is the imposed tangential velocity. In the case of external elastic stiffness, two velocity weakening regimes can be identified, the first is identical to the gravity case with a 1/V^2 dependence, the second appears at higher velocities and is characterized by a 1/V variation. The characteristic velocity of this second cross-over depends on the roughness and the elastic stiffness. The statistical distribution of ballistic flight distances is analysed, and is shown to reveal in all cases the self-affinity of the contacting surfaces. Nous analysons la dépendence en vitesse du frottement entre deux solides limités par une surface rugueuse auto-affine comme celle d'une surface de fracture. Le solide supérieur est soumis soit à la gravité, soit à une raideur élastique externe, et est entraîné à vitesse horizontale constante V sur le solide inférieur fixe. A faible vitesse, le coefficient de friction apparent, est constant. A forte vitesse, le coefficient de friction apparent devient inversement proportionnel à la vitesse. Cette dépendance peut être reliée à la variation du temps

  15. Data Stream Clustering With Affinity Propagation

    KAUST Repository

    Zhang, Xiangliang

    2014-07-09

    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  16. Affine and Projective Tree Metric Theorems

    CERN Document Server

    Harel, Matan; Pachter, Lior

    2011-01-01

    The tree metric theorem provides a combinatorial four point condition that characterizes dissimilarity maps derived from pairwise compatible split systems. A similar (but weaker) four point condition characterizes dissimilarity maps derived from circular split systems (Kalmanson metrics). The tree metric theorem was first discovered in the context of phylogenetics and forms the basis of many tree reconstruction algorithms, whereas Kalmanson metrics were first considered by computer scientists, and are notable in that they are a non-trivial class of metrics for which the traveling salesman problem is tractable. We present a unifying framework for these theorems based on combinatorial structures that are used for graph planarity testing. These are (projective) PC-trees, and their affine analogs, PQ-trees. In the projective case, we generalize a number of concepts from clustering theory, including hierarchies, pyramids, ultrametrics and Robinsonian matrices, and the theorems that relate them. As with tree metric...

  17. Gravitational Goldstone fields from affine gauge theory

    CERN Document Server

    Tresguerres, R

    2000-01-01

    In order to facilitate the application of standard renormalization techniques, gravitation should be decribed, if possible, in pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincare or the affine group. This embodies the translational as well as the linear connection. However, the coframe is not the standard Yang-Mills type gauge field of the translations, since it lacks the inhomogeneous gradient term in the gauge transformations. By explicitly restoring the "hidden" piece responsible for this behavior within the framework of nonlinear realizations, the usual geometrical interpretation of the dynamical theory becomes possible, and in addition one can avoid the metric or coframe degeneracy which would otherwise interfere with the integrations within the path integral. We claim that nonlinear realizations provide a general mathematical scheme clarifying the foundations of gauge theories of spacetime symmetries. When applied to construct the Yang-Mills theory of the aff...

  18. Automatic gesture analysis using constant affine velocity.

    Science.gov (United States)

    Cifuentes, Jenny; Boulanger, Pierre; Pham, Minh Tu; Moreau, Richard; Prieto, Flavio

    2014-01-01

    Hand human gesture recognition has been an important research topic widely studied around the world, as this field offers the ability to identify, recognize, and analyze human gestures in order to control devices or to interact with computer interfaces. In particular, in medical training, this approach is an important tool that can be used to obtain an objective evaluation of a procedure performance. In this paper, some obstetrical gestures, acquired by a forceps, were studied with the hypothesis that, as the scribbling and drawing movements, they obey the one-sixth power law, an empirical relationship which connects path curvature, torsion, and euclidean velocity. Our results show that obstetrical gestures have a constant affine velocity, which is different for each type of gesture and based on this idea this quantity is proposed as an appropriate classification feature in the hand human gesture recognition field.

  19. Affine trajectory correction for nonholonomic mobile robots

    CERN Document Server

    Pham, Quang-Cuong

    2011-01-01

    Planning trajectories for nonholonomic systems is difficult and computationally expensive. When facing unexpected events, it may therefore be preferable to deform in some way the initially planned trajectory rather than to re-plan entirely a new one. We suggest here a method based on affine transformations to make such deformations. This method is exact and fast: the deformations and the resulting trajectories can be computed algebraically, in one step, and without any trajectory re-integration. To demonstrate the possibilities offered by this new method, we use it to derive position correction, orientation correction, obstacle avoidance and feedback control algorithms for the general class of planar wheeled robots and for a tridimensional underwater vehicle.

  20. Self-affinity and nonextensivity of sunspots

    Energy Technology Data Exchange (ETDEWEB)

    Moret, M.A., E-mail: mamoret@gmail.com [Programa de Modelagem Computacional, SENAI, Cimatec, Av. Orlando Gomes, 1845, Piatã, 41650-010 Salvador, Bahia (Brazil); UNEB, Rua Silveira Martins, 2555, Cabula, 41150-000 Salvador, Bahia (Brazil)

    2014-01-24

    In this paper we study the time series of sunspots by using two different approaches, analyzing its self-affine behavior and studying its distribution. The long-range correlation exponent α has been calculated via Detrended Fluctuation Analysis and the power law vanishes to values greater than 11 years. On the other hand, the distribution of the sunspots obeys a q-exponential decay that suggests a non-extensive behavior. This observed characteristic seems to take an alternative interpretation of the sunspots dynamics. The present findings suggest us to propose a dynamic model of sunspots formation based on a nonlinear Fokker–Planck equation. Therefore its dynamic process follows the generalized thermostatistical formalism.

  1. Affine connection form of Regge calculus

    CERN Document Server

    Khatsymovsky, V M

    2015-01-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the 3-simplices which play a role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4,R) of the connection matrices. As a result, we have some action invariant w. r. t. arbitrary change of coordinates of the vertices (and related GL(4,R) transformations in...

  2. Capture of formaldehyde by adsorption on nanoporous materials.

    Science.gov (United States)

    Bellat, Jean-Pierre; Bezverkhyy, Igor; Weber, Guy; Royer, Sébastien; Averlant, Remy; Giraudon, Jean-Marc; Lamonier, Jean-François

    2015-12-30

    The aim of this work is to assess the capability of a series of nanoporous materials to capture gaseous formaldehyde by adsorption in order to develop air treatment process and gas detection in workspaces or housings. Adsorption-desorption isotherms have been accurately measured at room temperature by TGA under very low pressure (pmesoporous silica (SBA15), activated carbon (AC NORIT RB3) and metal organic framework (MOF, Ga-MIL-53), exhibiting a wide range of pore sizes and surface properties. Results reveal that the NaX, NaY and CuX faujasite (FAU) zeolites are materials which show strong adsorption capacity and high affinity toward formaldehyde. In addition, these materials can be completely regenerated by heating at 200°C under vacuum. These cationic zeolites are therefore promising candidates as adsorbents for the design of air depollution process or gas sensing applications.

  3. Tandem come tirocinio: la riflessione nel corso dell'azione - in un tandem in presenza italiano-portoghese

    Directory of Open Access Journals (Sweden)

    Maria Luisa Vassallo

    2006-04-01

    Full Text Available II presente studio è dedicato al Tandem, un metodo di studio delle lingue straniere autonomo e collaborativo. Esso illustra alcune potenzialità di questa forma didattica per la formazione degli insegnanti, utilizzando il concetto di riflessione nel corso dell'azione elaborato dal filosofo statunitense Donald Schön (1983. Il capitolo 1 introduce il metodo Tandem. Il capitolo 2 analizza il Tandem alla luce della teoria di Schön. Il capitolo 3 descrive l'aspetto riflessivo in un Tandem in presenza, svolto nel 2004 in Brasile. II capitolo 4 propone alcuni motivi per considerare il metodo Tandem un contesto complementare utile per la formazione alla pratica docente attraverso il tirocinio.

  4. Indefinite Affine Hyperspheres Admitting a Pointwise Symmetry. Part 2

    Directory of Open Access Journals (Sweden)

    Christine Scharlach

    2009-10-01

    Full Text Available An affine hypersurface M is said to admit a pointwise symmetry, if there exists a subgroup G of Aut(T_pM for all p in M, which preserves (pointwise the affine metric h, the difference tensor K and the affine shape operator S. Here, we consider 3-dimensional indefinite affine hyperspheres, i.e. S = HId (and thus S is trivially preserved. In Part 1 we found the possible symmetry groups G and gave for each G a canonical form of K. We started a classification by showing that hyperspheres admitting a pointwise Z_2 × Z_2 resp. R-symmetry are well-known, they have constant sectional curvature and Pick invariant J < 0 resp. J = 0. Here, we continue with affine hyperspheres admitting a pointwise Z_3- or SO(2-symmetry. They turn out to be warped products of affine spheres (Z_3 or quadrics (SO(2 with a curve.

  5. Classical affine W-algebras associated to Lie superalgebras

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)

    2016-02-15

    In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent.

  6. Abacus models for parabolic quotients of affine Weyl groups

    CERN Document Server

    Hanusa, Christopher R H

    2011-01-01

    We introduce abacus diagrams that describe minimal length coset representatives in affine Weyl groups of types B, C, and D. These abacus diagrams use a realization of the affine Weyl group of type C due to Eriksson to generalize a construction of James for the symmetric group. We also describe several combinatorial models for these parabolic quotients that generalize classical results in affine type A related to core partitions.

  7. Fast Affinity Propagation Clustering based on Machine Learning

    OpenAIRE

    Shailendra Kumar Shrivastava; J. L. Rana; DR.R.C.JAIN

    2013-01-01

    Affinity propagation (AP) was recently introduced as an un-supervised learning algorithm for exemplar based clustering. In this paper a novel Fast Affinity Propagation clustering Approach based on Machine Learning (FAPML) has been proposed. FAPML tries to put data points into clusters based on the history of the data points belonging to clusters in early stages. In FAPML we introduce affinity learning constant and dispersion constant which supervise the clustering process. FAPML also enforces...

  8. Surfaces in 4-space from the affine differential geometry viewpoint

    OpenAIRE

    Luis Florial Espinoza Sánchez

    2014-01-01

    In this thesis, we study locally strictly convex surfaces from the affine differential viewpoint and generalize some tools for locally strictly submanifolds of codimension 2. We introduce a family of affine metrics on a locally strictly convex surface M in affine 4-space. Then, we define the symmetric and antisymmetric equiaffine planes associated with each metric. We show that if M is immersed in a locally atrictly convex hyperquadric, then the symmetric and the antisymmetric planes coincid...

  9. Folded tandem ion accelerator facility at Trombay

    Indian Academy of Sciences (India)

    P Singh

    2001-08-01

    The folded tandem ion accelerator (FOTIA) project at BARC has been commissioned. The analysed carbon beams of 40 nA(3+) and 25 nA(4+), at terminal voltage of 2.5 MV with N2 + CO2 as insulating gas, were obtained. The beams were characterized by performing the Rutherford back scattering (RBS) on gold, tin and iron targets. The beam energy of 12.5 MeV for 12C4+ was consistent with the terminal voltage of 2.5 MV. The N2 + CO2 mixture is being replaced by SF6 gas in order to achieve 6 MV on the terminal. In this paper, some of the salient features of the FOTIA and its present status are discussed.

  10. Realistic costs of carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Al Juaied, Mohammed (Harvard Univ., Cambridge, MA (US). Belfer Center for Science and International Affiaris); Whitmore, Adam (Hydrogen Energy International Ltd., Weybridge (GB))

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS

  11. Silica-templated melamine-formaldehyde resin derived adsorbents for CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    C. Pevida; T.C. Drage; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). School of Chemical and Environmental Engineering

    2008-09-15

    Adsorption on porous solids is an emerging alternative for CO{sub 2} capture that seeks to reduce the costs associated to the capture step. The enhancement of a specific adsorption capacity may be carried out by increasing the affinity of the adsorbent surface to CO{sub 2}. Nitrogen enrichment is reported to be effective in introducing basic functionalties that enhances the specific adsorbent-adsorbate interaction for CO{sub 2}. In this work a templating technique was used to produce highly porous nitrogen enriched carbons from melamine-formaldehyde resins. Nitrogen incorporated into the polymer matrix results in the greater stability of the adsorbents in terms of volatile and thermal loss of nitrogen. CO{sub 2} capture performances were evaluated between 25{sup o}C and 75{sup o}C in a thermobalance. CO{sub 2} adsorption capacities up to 2.25 mmol g{sup -1} of CO{sub 2} at 25{sup o}C were achieved. Both texture and surface chemistry influence the CO{sub 2} capture performance of the adsorbents. The carbonisation temperature used during the synthesis step controls the nitrogen functional groups present, as determined by XPS, with the loss of triazine nitrogen with increasing carbonisation temperature proposed to account for the decreased CO{sub 2} affinity.

  12. Inhibition of Xanthine Oxidase Activity by Gnaphalium Affine Extract

    Institute of Scientific and Technical Information of China (English)

    Wei-qing Lin; Jian-xiang Xie; Xiao-mu Wu; Lin Yang; Hai-dong Wang

    2014-01-01

    Objective To evaluate the inhibitory effect of Gnaphalium affine extracts on xanthine oxidase (XO) activity in vitro and to analyze the mechanism of this effect. Methods In this in vitro study, Kinetic measurements were performed in 4 different inhibitor concentrations and 5 different xanthine concentrations (60, 100, 200, 300, 400 μmol/L). Dixon and Lineweaver-Burk plot analysis were used to determine Ki values and the inhibition mode for the compounds isolated from Gnaphalium affine extract. Results Four potent xanthine oxidase inhibitors were found in 95% ethanolic (v/v) Gnaphalium affine extract. Among them, the flavone Eupatilin exhibited the strongest inhibitory effect on XO with a inhibition constant (Ki) of 0.37μmol/L, lower than the Ki of allopurinol (4.56 mol/L), a known synthetic XO inhibitor. Apigenin (Ki of 0.56μmol/L, a proportion of 0.0053‰in Gnaphalium affine), luteolin (Ki of 2.63 μmol/L, 0.0032‰ in Gnaphalium affine) and 5-hydroxy-6,7,3’,4’-tetramethoxyflavone (Ki of 3.15μmol/L, 0.0043‰ in Gnaphalium affine) also contributed to the inhibitory effect of Gnaphalium affine extract on XO activity. Conclusions These results suggest that the use of Gnaphalium affine in the treatment of gout could be attributed to its inhibitory effect on XO. This study provides a rational basis for the traditional use of Gnaphalium affine against gout.

  13. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  14. Catch of channel catfish with tandem-set hoop nets and gill nets in lentic systems of Nebraska

    Science.gov (United States)

    Richters, Lindsey K.; Pope, Kevin L.

    2011-01-01

    Twenty-six Nebraska water bodies representing two ecosystem types (small standing waters and large standing waters) were surveyed during 2008 and 2009 with tandem-set hoop nets and experimental gill nets to determine if similar trends existed in catch rates and size structures of channel catfish Ictalurus punctatus captured with these gears. Gear efficiency was assessed as the number of sets (nets) that would be required to capture 100 channel catfish given observed catch per unit effort (CPUE). Efficiency of gill nets was not correlated with efficiency of hoop nets for capturing channel catfish. Small sample sizes prohibited estimation of proportional size distributions in most surveys; in the four surveys for which sample size was sufficient to quantify length-frequency distributions of captured channel catfish, distributions differed between gears. The CPUE of channel catfish did not differ between small and large water bodies for either gear. While catch rates of hoop nets were lower than rates recorded in previous studies, this gear was more efficient than gill nets at capturing channel catfish. However, comparisons of size structure between gears may be problematic.

  15. Sugarcane Tandem Mills Operation at Two Hydraulic Pressure Levels

    Directory of Open Access Journals (Sweden)

    Jorge Michel Corrales-Suárez

    2015-01-01

    Full Text Available Among the areas with more energy consumption in a sugar factory is the tandem of mills. The applied hydraulic pressure on the superior mace is one of the variables that have influence on this energy consumption. Hydraulic pressures were decreased in a value that did not affect the extraction process efficiency to determine the possibilities of decreasing this energy consumption. The research was carried out in two sugar cane tandems of six mills. The pressures were only varied in the extraction mills in humid according to a statistical design of experiments in random blocks. The results were analyzed by means of the analysis of variance of double classification. The independent variables were the hydraulic pressures in the intermediate mills while the dependent variables were the % pol and % humidity of the final bagasse. The hydraulic pressures of the intermediate mills were reduced 3.45 MPa in the Tandem 1 and 2.07 MPa in the Tandem 2. It was demonstrated that under the conditions of the experiment, the employment of working hydraulic pressures smaller than the usually established ones for each tandem did not affect the extraction process of the sugar cane sucrose significantly, but decreased 11.75% the power demand on tandem 1 and 8.17% on tandem 2.

  16. Integration of Faradaic electrochemical impedance spectroscopy into a scalable surface plasmon biosensor for in tandem detection.

    Science.gov (United States)

    Hong, Brandon; Sun, Alexander; Pang, Lin; Venkatesh, A G; Hall, Drew; Fainman, Yeshaiahu

    2015-11-16

    We present an integrated label-free biosensor based on surface plasmon resonance (SPR) and Faradaic electrochemical impedance spectroscopy (f-EIS) sensing modalities, for the simultaneous detection of biological analytes. Analyte detection is based on the angular spectroscopy of surface plasmon resonance and the extraction of charge transfer resistance values from reduction-oxidation reactions at the gold surface, as responses to functionalized surface binding events. To collocate the measurement areas and fully integrate the modalities, holographically exposed thin-film gold SPR-transducer gratings are patterned into coplanar electrodes for tandem impedance sensing. Mutual non-interference between plasmonic and electrochemical measurement processes is shown, and using our scalable and compact detection system, we experimentally demonstrate biotinylated surface capture of neutravidin concentrations as low as 10 nM detection, with a 5.5 nM limit of detection.

  17. The cohomology of the affine Deligne-Lusztig varieties in the affine flag manifold of $GL_2$

    CERN Document Server

    Ivanov, Alexander

    2009-01-01

    This paper studies affine Deligne-Lusztig varieties in the affine flag manifold of GL_2. At first we determine all such varieties up to isomorphy. After this we investigate the representations of the sigma-stabilizer of an element b of the group on the etale cohomology of the affine Deligne-Lusztig variety X_w(b). We describe such representations as inductions from compact subgroups and in terms of noncuspidal representations.

  18. The Effectiveness of Classroom Capture Technology

    Science.gov (United States)

    Ford, Maire B.; Burns, Colleen E.; Mitch, Nathan; Gomez, Melissa M.

    2012-01-01

    The use of classroom capture systems (systems that capture audio and video footage of a lecture and attempt to replicate a classroom experience) is becoming increasingly popular at the university level. However, research on the effectiveness of classroom capture systems in the university classroom has been limited due to the recent development and…

  19. Marker-Free Human Motion Capture

    DEFF Research Database (Denmark)

    Grest, Daniel

    Human Motion Capture is a widely used technique to obtain motion data for animation of virtual characters. Commercial optical motion capture systems are marker-based. This book is about marker-free motion capture and its possibilities to acquire motion from a single viewing direction. The focus...

  20. Comparison among three anion exchange chromatographic supports to capture erythropoietin from cell culture supernatant

    Institute of Scientific and Technical Information of China (English)

    Lourdes HERNNDEZ; Diobel STEWART; Lourdes ZUMALACRREGUI; Daniel AMARO

    2015-01-01

    Affinity and ion exchange conventional chromatography have been used to capture erythropoietin ( EPO)from mammalian cell culture supernatant. Currently,chromatographic adsorbent perfusion is available, however a limited number of applications have been found in the literature. In this work,three anion exchange chromatographic supports( gel,membrane and monolithic)were evaluated in the capture step of the recombi-nant erythropoietin purification process. The influences of load and flow rate on each support performance were analyzed. Also the purity of the EPO molecules was determined. A productivity analysis,as a decision tool for larger scale implementation,was done. As a conclusion,the evaluated supports are technically suitable to cap-ture EPO with adequate recovery and good purity. However,the monolithic column admits high operating velocity,showing the highest adsorption capacity and productivity.

  1. Numerical evaluation of tandem rotor for highly loaded transonic fan

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bin; LIU Bao-jie

    2011-01-01

    Transonic tandem rotor was designed for highly loaded fan at a corrected tip speed of 381 m/s and another conventional rotor was designed as a baseline to evaluate the loading superiority of tandem rotor with three-dimensional (3-D) numerical simulation. The aft blade solidity and its impact on total loading level were studied in depth. The result indicates that tandem rotor has potential to achieve higher loading level and attain favorable aerodynamic performance in a wide range of loading coefficient 0. 55 ~ 0.68, comparing with the conventional rotor which produced a total pressure ratio of 2.0 and loading coefficient of 0. 42.

  2. A human β-III-spectrin spinocerebellar ataxia type 5 mutation causes high-affinity F-actin binding

    Science.gov (United States)

    Avery, Adam W.; Crain, Jonathan; Thomas, David D.; Hays, Thomas S.

    2016-01-01

    Spinocerebellar ataxia type 5 (SCA5) is a human neurodegenerative disease that stems from mutations in the SPTBN2 gene encoding the protein β-III-spectrin. Here we investigated the molecular consequence of a SCA5 missense mutation that results in a L253P substitution in the actin-binding domain (ABD) of β-III-spectrin. We report that the L253P substitution in the isolated β-III-spectrin ABD causes strikingly high F-actin binding affinity (Kd = 75.5 nM) compared to the weak F-actin binding affinity of the wild-type ABD (Kd = 75.8 μM). The mutation also causes decreased thermal stability (Tm = 44.6 °C vs 59.5 °C). Structural analyses indicate that leucine 253 is in a loop at the interface of the tandem calponin homology (CH) domains comprising the ABD. Leucine 253 is predicted to form hydrophobic contacts that bridge the CH domains. The decreased stability of the mutant indicates that these bridging interactions are probably disrupted, suggesting that the high F-actin binding affinity of the mutant is due to opening of the CH domain interface. These results support a fundamental role for leucine 253 in regulating opening of the CH domain interface and binding of the ABD to F-actin. This study indicates that high-affinity actin binding of L253P β-III-spectrin is a likely driver of neurodegeneration. PMID:26883385

  3. Microstructured block copolymer surfaces for control of microbe capture and aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ryan R [ORNL; Shubert, Katherine R [ORNL; Morrell, Jennifer L. [University of Tennessee, Knoxville (UTK); Lokitz, Bradley S [ORNL; Doktycz, Mitchel John [ORNL; Retterer, Scott T [ORNL

    2014-01-01

    The capture and arrangement of surface-associated microbes is influenced by biochemical and physical properties of the substrate. In this report, we develop lectin-functionalized substrates containing patterned, three-dimensional polymeric structures of varied shapes and densities and use these to investigate the effects of topology and spatial confinement on lectin-mediated microbe capture. Films of poly(glycidyl methacrylate)-block-4,4-dimethyl-2-vinylazlactone (PGMA-b-PVDMA) were patterned on silicon surfaces into line or square grid patterns with 5 m wide features and varied edge spacing. The patterned films had three-dimensional geometries with 900 nm film thickness. After surface functionalization with wheat germ agglutinin, the size of Pseudomonas fluorescens aggregates captured was dependent on the pattern dimensions. Line patterns with edge spacing of 5 m or less led to the capture of individual microbes with minimal formation of aggregates, while grid patterns with the same spacing also captured individual microbes with further reduction in aggregation. Both geometries allowed for increases in aggregate size distribution with increased in edge spacing. These engineered surfaces combine spatial confinement with affinity-based microbe capture based on exopolysaccharide content to control the degree of microbe aggregation, and can also be used as a platform to investigate intercellular interactions and biofilm formation in microbial populations of controlled sizes.

  4. Summary of the Tandem Cylinder Solutions from the Benchmark Problems for Airframe Noise Computations-I Workshop

    Science.gov (United States)

    Lockard, David P.

    2011-01-01

    Fifteen submissions in the tandem cylinders category of the First Workshop on Benchmark problems for Airframe Noise Computations are summarized. Although the geometry is relatively simple, the problem involves complex physics. Researchers employed various block-structured, overset, unstructured and embedded Cartesian grid techniques and considerable computational resources to simulate the flow. The solutions are compared against each other and experimental data from 2 facilities. Overall, the simulations captured the gross features of the flow, but resolving all the details which would be necessary to compute the noise remains challenging. In particular, how to best simulate the effects of the experimental transition strip, and the associated high Reynolds number effects, was unclear. Furthermore, capturing the spanwise variation proved difficult.

  5. Platelet affinity for burro aorta collagen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.D.

    1977-10-01

    Despite ingenious concepts, there are no unequivocal clues as to what, when, and how some undefined biochemical factor(s) or constituent(s) that localizes in the arterial wall can precipitate a thromboatheromatous lesion or arterial disease. The present study focused on the extraction, partial purification, and characterization of a collagen-active platelet stimulator from the aortas of aged burros. The aggregator moiety in the aorta extracts invariably had a higher affinity for platelets in citrated platelet-rich plasma of human beings than for platelets of homologous burros. The platelet-aggregating factor(s) in the aorta extract was retained by incubation with ..cap alpha..-chymotrypsin. Platelet-aggregating activity was rapidly abolished after incubation with collagenase, as determined by platelet-aggregometry tests. Evidence based on light microscope and polysaccharide histochemical reactions indicates a probability that the intracellular amorphous matrix (PAS-positive) and filamentous components (PTAH-positive) expelled from smooth muscle cells disrupted during homogenization of the aorta may be a principal source of a precursor collagen species which is a potent inducer of platelet aggregation.

  6. Affine connection form of Regge calculus

    Science.gov (United States)

    Khatsymovsky, V. M.

    2016-12-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the three-simplices which play the role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4, R) of the connection matrices. As a result, we have some action invariant w.r.t. arbitrary change of coordinates of the vertices (and related GL(4, R) transformations in the four-simplices). Excluding GL(4, R) connection from this action via the equations of motion we have exactly the Regge action for the considered spacetime.

  7. Affinity of guanosine derivatives for polycytidylate revisited

    Science.gov (United States)

    Kanavarioti, A.; Hurley, T. B.; Baird, E. E.

    1995-01-01

    Evidence is presented for complexation of guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) with polycytidylate (poly(C)) at pH 8.0 and 23 degrees C in the presence of 1.0 M NaCl2 and 0.2 M MgCl2 in water. The association of 2-MeImpG with poly(C) was investigated using UV-vis spectroscopy as well as by monitoring the kinetics of the nucleophilic substitution reaction of the imidazole moiety by amines. The results of both methods are consistent with moderately strong poly(C) 2-MeImpG complexation and the spectrophotometric measurements allowed the construction of a binding isotherm with a concentration of 2-MeImpG equal to 5.55 +/- 0.15 mM at half occupancy. UV spectroscopy was employed to establish the binding of other guanosine derivatives on poly(C). These derivatives are guanosine 5'-monophosphate (5'GMP), guanosine 5'-monophosphate imidazolide (ImpG), and guanosine 5'-monophosphate morpholidate (morpG). Within experimental error these guanosine derivatives exhibit the same affinity for poly(C) as 2-MeImpG.

  8. Halo Effect on Direct Neutron Capture Process

    Institute of Scientific and Technical Information of China (English)

    刘祖华; 周宏余

    2004-01-01

    We calculate the capture cross sections of the 10Be(n,γ) 11 Be reaction by means of the asymptotic normalization coefficient method and demonstrate the halo effects on the capture cross sections for the direct radiative neutron capture where a p-, s- or d-wave neutron is captured into an s-orbit or p-orbit in 11 Be by emitting an E1 γ-ray,respectively. The result shows that the enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo, which is clearly illustrated by the reduced transition amplitude function.

  9. Label-free detection and identification of protein ligands captured by receptors in a polymerized planar lipid bilayer using MALDI-TOF MS.

    Science.gov (United States)

    Liang, Boying; Ju, Yue; Joubert, James R; Kaleta, Erin J; Lopez, Rodrigo; Jones, Ian W; Hall, Henry K; Ratnayaka, Saliya N; Wysocki, Vicki H; Saavedra, S Scott

    2015-04-01

    Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) coupled with affinity capture is a well-established method to extract biological analytes from complex samples followed by label-free detection and identification. Many bioanalytes of interest bind to membrane-associated receptors; however, the matrices and high-vacuum conditions inherent to MALDI-TOF MS make it largely incompatible with the use of artificial lipid membranes with incorporated receptors as platforms for detection of captured proteins and peptides. Here we show that cross-linking polymerization of a planar supported lipid bilayer (PSLB) provides the stability needed for MALDI-TOF MS analysis of proteins captured by receptors embedded in the membrane. PSLBs composed of poly(bis-sorbylphosphatidylcholine) (poly(bis-SorbPC)) and doped with the ganglioside receptors GM1 and GD1a were used for affinity capture of the B subunits of cholera toxin, heat-labile enterotoxin, and pertussis toxin. The three toxins were captured simultaneously, then detected and identified by MS on the basis of differences in their molecular weights. Poly(bis-SorbPC) PSLBs are inherently resistant to nonspecific protein adsorption, which allowed selective toxin detection to be achieved in complex matrices (bovine serum and shrimp extract). Using GM1-cholera toxin subunit B as a model receptor-ligand pair, we estimated the minimal detectable concentration of toxin to be 4 nM. On-plate tryptic digestion of bound cholera toxin subunit B followed by MS/MS analysis of digested peptides was performed successfully, demonstrating the feasibility of using the PSLB-based affinity capture platform for identification of unknown, membrane-associated proteins. Overall, this work demonstrates that combining a poly(lipid) affinity capture platform with MALDI-TOF MS detection is a viable approach for capture and proteomic characterization of membrane-associated proteins in a label-free manner.

  10. Downstream processing of polysaccharide degrading enzymes by affinity chromatography.

    NARCIS (Netherlands)

    Somers, W.A.C.

    1992-01-01

    The objective of this study was the development of affinity matrices to isolate and purify a number of polysaccharide degrading enzymes and the application of these adsorbents in the large- scale purification of the enzymes from fermentation broths. Affinity adsorbents were developed for endo-polyga

  11. Affine group formulation of the Standard Model coupled to gravity

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Ching-Yi, E-mail: l2897107@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Taiwan (China); Ita, Eyo, E-mail: ita@usna.edu [Department of Physics, US Naval Academy, Annapolis, MD (United States); Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Taiwan (China)

    2014-04-15

    In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauder’s affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant Λ, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and Yang–Mills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the Yang–Mills and Higgs energy densities, are composed with York’s integrated time functional. The result, when combined with the imaginary part of the Chern–Simons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: •Wheeler–DeWitt equation (WDW) quantized as affine algebra, realizing Klauder’s program. •WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. •WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. •Constructed a family of physical states for the full, coupled theory via affine coherent states. •Fundamental uncertainty relation, predicated on non-vanishing cosmological constant.

  12. Germinal center reaction: antigen affinity and presentation explain it all.

    Science.gov (United States)

    Oropallo, Michael A; Cerutti, Andrea

    2014-07-01

    The selection and expansion of B cells undergoing affinity maturation in the germinal center is a hallmark of humoral immunity. A recent paper in Nature provides new insights into the relationships between the affinity of the immunoglobulin receptor for antigen, the ability of B cells to present antigen to T cells, and the processes of selection, mutation, and clonal expansion in the germinal center.

  13. Self-affine roughness influence on redox reaction charge admittance

    NARCIS (Netherlands)

    Palasantzas, G

    2005-01-01

    In this work we investigate the influence of self-affine electrode roughness on the admittance of redox reactions during facile charge transfer kinetics. The self-affine roughness is characterized by the rms roughness amplitude w, the correlation length xi and the roughness exponent H (0

  14. Synthesis of tetracycline analogs and their bone affinities

    Institute of Scientific and Technical Information of China (English)

    Wen Cai Huang; Hu Zheng; Ling Ling Weng

    2008-01-01

    Tetracycline analogs were designed and synthesized and their bone affinities were tested on hydroxyapatite. The results showedthat the carbonyl-amide-enol structure in A ring and phenol-ketone structure in BCD ring may be responsible for tetracycline's highbone affinity and either A ring or BCD ring has a planar conformation is essential.

  15. The Affine Complete Hypersurfaces of Constant Gauss-Kronecker Curvature

    Institute of Scientific and Technical Information of China (English)

    Bao Fu WANG

    2009-01-01

    Given a bounded convex domain Ω with C∞ boundary and a function φ∈ C∞ ( partial deriv Ω), Li-Simon-Chen can construct an Euclidean complete and W-complete convex hypersurface M with constant affine Gauss-Kronecker curvature, and they guess the M is also affine complete. In this paper, we give a confirmation answer.

  16. Ordinary matter in nonlinear affine gauge theories of gravitation

    CERN Document Server

    Tiemblo, A; Tiemblo, A; Tresguerres, R

    1994-01-01

    We present a general framework to include ordinary fermionic matter in the metric--affine gauge theories of gravity. It is based on a nonlinear gauge realization of the affine group, with the Lorentz group as the classification subgroup of the matter and gravitational fields.

  17. Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators

    Science.gov (United States)

    Fields, Jessica; Copp, Martha

    2015-01-01

    Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…

  18. Isolation of bovine serum albumin from whey using affinity chromatography

    NARCIS (Netherlands)

    Besselink, T.; Janssen, A.E.M.; Boom, R.M.

    2015-01-01

    The adsorption of bovine serum albumin (BSA) to a chromatography resin with immobilised llama antibody fragments as affinity ligands was investigated. The maximum adsorption capacity of the affinity resin was 21.6 mg mL-1 with a Langmuir equilibrium constant of 20.4 mg mg-1. Using packed bed chromat

  19. SHP-1 phosphatase activity counteracts increased T cell receptor affinity.

    Science.gov (United States)

    Hebeisen, Michael; Baitsch, Lukas; Presotto, Danilo; Baumgaertner, Petra; Romero, Pedro; Michielin, Olivier; Speiser, Daniel E; Rufer, Nathalie

    2013-03-01

    Anti-self/tumor T cell function can be improved by increasing TCR-peptide MHC (pMHC) affinity within physiological limits, but paradoxically further increases (K(d) affinity for the tumor antigen HLA-A2/NY-ESO-1, we investigated the molecular mechanisms underlying this high-affinity-associated loss of function. As compared with cells expressing TCR affinities generating optimal function (K(d) = 5 to 1 μM), those with supraphysiological affinity (K(d) = 1 μM to 15 nM) showed impaired gene expression, signaling, and surface expression of activatory/costimulatory receptors. Preferential expression of the inhibitory receptor programmed cell death-1 (PD-1) was limited to T cells with the highest TCR affinity, correlating with full functional recovery upon PD-1 ligand 1 (PD-L1) blockade. In contrast, upregulation of the Src homology 2 domain-containing phosphatase 1 (SHP-1/PTPN6) was broad, with gradually enhanced expression in CD8(+) T cells with increasing TCR affinities. Consequently, pharmacological inhibition of SHP-1 with sodium stibogluconate augmented the function of all engineered T cells, and this correlated with the TCR affinity-dependent levels of SHP-1. These data highlight an unexpected and global role of SHP-1 in regulating CD8(+) T cell activation and responsiveness and support the development of therapies inhibiting protein tyrosine phosphatases to enhance T cell-mediated immunity.

  20. Frame-independent mechanics:geometry on affine bundles

    OpenAIRE

    Grabowska, K.; Grabowski, J.; Urbanski, P.

    2005-01-01

    Main ideas of the differential geometry on affine bundles are presented. Affine counterparts of Lie algebroid and Poisson structures are introduced and discussed. The developed concepts are applied in a frame-independent formulation of the time-dependent and the Newtonian mechanics.

  1. Convergence of generic infinite products of affine operators

    Directory of Open Access Journals (Sweden)

    S. Reich

    1999-01-01

    Full Text Available We establish several results concerning the asymptotic behavior of random infinite products of generic sequences of affine uniformly continuous operators on bounded closed convex subsets of a Banach space. In addition to weak ergodic theorems we also obtain convergence to a unique common fixed point and more generally, to an affine retraction.

  2. High affinity retinoic acid receptor antagonists: analogs of AGN 193109.

    Science.gov (United States)

    Johnson, A T; Wang, L; Gillett, S J; Chandraratna, R A

    1999-02-22

    A series of high affinity retinoic acid receptor (RAR) antagonists were prepared based upon the known antagonist AGN 193109 (2). Introduction of various phenyl groups revealed a preference for substitution at the para-position relative to the meta-site. Antagonists with the highest affinities for the RARs possessed hydrophobic groups, however, the presence of polar functionality was also well tolerated.

  3. Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators

    Science.gov (United States)

    Fields, Jessica; Copp, Martha

    2015-01-01

    Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…

  4. Peptide Nucleic Acids Having Enhanced Binding Affinity and Sequence Specificity

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than a corresponding DNA strand, and exhibit increased sequence specificity and binding affinity. Methods of increasing binding affinity and sequence specificity of peptide nucleic aci...

  5. Capture of Irregular Satellites at Jupiter

    CERN Document Server

    Nesvorny, D; Deienno, R

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early Solar System instability when encounters between the outer planets occurred (Nesvorny, Vokrouhlicky & Morbidelli 2007, AJ 133; hereafter NVM07). NVM07 already showed that the irregular satellites of Saturn, Uranus and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary d...

  6. IMPLEMENTASI ENKRIPSI DEKRIPSI ALGORITMA AFFINE CIPHER BERBASIS ANDROID

    Directory of Open Access Journals (Sweden)

    Sasono Wibowo

    2014-11-01

    Full Text Available Perkembangan Teknologi Informasi yang cukup pesat khususnya dalam bidang komunikasi menjadikan komunikasi sangat mudah namun dalam implementasinya perlu adanya keamanan tentang informasi yang disampaikan. Dalam komunikasi antar orang pasti memiliki pembicaraan informasi yang bersifat privat atau orang lain tidak boleh tahu tentang pembicaraan yang terjadi. Diperlukannya keamanan untuk menjaga kerahasiaan informasi pada saat komunikasi. Masyarakat lebih sering menggunakan komunikasi dengan telepon seluler karena dinilai mudah dibawa dan tidak repot menggunakannya. Kriptografi yang biasa dikenal sebagai ilmu yang mempelajari bagaimana cara menyembunyikan pesan bisa diterapkan dalam aplikasi pada telepon seluler sebagai contoh smartphone android. Dengan mengimplementasikan algoritma affine cipher maka aplikasi yang akan dibuat bisa mengubah isi pesan yang ada dan dapat mengamankan informasi yang ada. Algoritma affine cipher merupakan perkembangan dari algoritma caesar dimana algoritma affine cipher menggunakan dua kunci. Dengan mengimplementasikan algoritma affine cipher ke dalam android maka diharapkan kita bisa menyimpan informasi dari siapapun tanpa terbaca. Kata Kunci : Kriptografi, Affine Cipher, android, Implementasi, Informasi

  7. Duals of Affine Grassmann Codes and Their Relatives

    DEFF Research Database (Denmark)

    Beelen, P.; Ghorpade, S. R.; Hoholdt, T.

    2012-01-01

    Affine Grassmann codes are a variant of generalized Reed-Muller codes and are closely related to Grassmann codes. These codes were introduced in a recent work by Beelen Here, we consider, more generally, affine Grassmann codes of a given level. We explicitly determine the dual of an affine...... Grassmann code of any level and compute its minimum distance. Further, we ameliorate the results by Beelen concerning the automorphism group of affine Grassmann codes. Finally, we prove that affine Grassmann codes and their duals have the property that they are linear codes generated by their minimum......-weight codewords. This provides a clean analogue of a corresponding result for generalized Reed-Muller codes....

  8. SYMTRAN - A Time-dependent Symmetric Tandem Mirror Transport Code

    Energy Technology Data Exchange (ETDEWEB)

    Hua, D; Fowler, T

    2004-06-15

    A time-dependent version of the steady-state radial transport model in symmetric tandem mirrors in Ref. [1] has been coded up and first tests performed. Our code, named SYMTRAN, is an adaptation of the earlier SPHERE code for spheromaks, now modified for tandem mirror physics. Motivated by Post's new concept of kinetic stabilization of symmetric mirrors, it is an extension of the earlier TAMRAC rate-equation code omitting radial transport [2], which successfully accounted for experimental results in TMX. The SYMTRAN code differs from the earlier tandem mirror radial transport code TMT in that our code is focused on axisymmetric tandem mirrors and classical diffusion, whereas TMT emphasized non-ambipolar transport in TMX and MFTF-B due to yin-yang plugs and non-symmetric transitions between the plugs and axisymmetric center cell. Both codes exhibit interesting but different non-linear behavior.

  9. Zinc Mediated Tandem Fragmentation-Allylation of Methyl 5-Iodopentofuranosides

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Madsen, Robert

    1999-01-01

    In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols....

  10. Solar-to-Chemical Energy Conversion with Photoelectrochemical Tandem Cells.

    Science.gov (United States)

    Sivula, Kevin

    2013-01-01

    Efficiently and inexpensively converting solar energy into chemical fuels is an important goal towards a sustainable energy economy. An integrated tandem cell approach could reasonably convert over 20% of the sun's energy directly into chemical fuels like H2 via water splitting. Many different systems have been investigated using various combinations of photovoltaic cells and photoelectrodes, but in order to be economically competitive with the production of H2 from fossil fuels, a practical water splitting tandem cell must optimize cost, longevity and performance. In this short review, the practical aspects of solar fuel production are considered from the perspective of a semiconductor-based tandem cell and the latest advances with a very promising technology - metal oxide photoelectrochemical tandem cells - are presented.

  11. Cage-based performance capture

    CERN Document Server

    Savoye, Yann

    2014-01-01

    Nowadays, highly-detailed animations of live-actor performances are increasingly easier to acquire and 3D Video has reached considerable attentions in visual media production. In this book, we address the problem of extracting or acquiring and then reusing non-rigid parametrization for video-based animations. At first sight, a crucial challenge is to reproduce plausible boneless deformations while preserving global and local captured properties of dynamic surfaces with a limited number of controllable, flexible and reusable parameters. To solve this challenge, we directly rely on a skin-detached dimension reduction thanks to the well-known cage-based paradigm. First, we achieve Scalable Inverse Cage-based Modeling by transposing the inverse kinematics paradigm on surfaces. Thus, we introduce a cage inversion process with user-specified screen-space constraints. Secondly, we convert non-rigid animated surfaces into a sequence of optimal cage parameters via Cage-based Animation Conversion. Building upon this re...

  12. Muon capture by silicon 28

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, D.S. [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics; Bauer, J. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Evans, J. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Gorringe, T.P. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Johnson, B.L. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Kalvoda, S. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Porter, R. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Siebels, B. [Kentucky Univ., Lexington, KY (United States). Dept. of Physics; Gete, E. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Measday, D.F. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Moftah, B.A. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Stanislaus, S. [Valparaiso Univ., IN (United States). Dept. of Physics

    1996-12-01

    A measurement has been made of the angular correlation of the neutrino with the 1229 keV {gamma}-ray from the de-excitation of the 2201 keV 1{sup +} level in aluminum-28, following muon capture in silicon-28. To suppress the neutron-induced background in the HPGe detector, a coincidence in a NaI array is required with the 942 keV {gamma}-ray in the de-excitation cascade. The lifetime of the 2201 keV level is found to be 61{+-}4{+-}9 fs. The correlation coefficient {alpha} is found to be 0.36{+-}0.06 implying g{sub P}/g{sub A}=0{sup +3.5}{sub -3}. (orig.).

  13. Workshop on neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fairchild, R.G.; Bond, V.P. (eds.)

    1986-01-01

    Potentially optimal conditions for Neutron Capture Therapy (NCT) may soon be in hand due to the anticipated development of band-pass filtered beams relatively free of fast neutron contaminations, and of broadly applicable biomolecules for boron transport such as porphyrins and monoclonal antibodies. Consequently, a number of groups in the US are now devoting their efforts to exploring NCT for clinical application. The purpose of this Workshop was to bring these groups together to exchange views on significant problems of mutual interest, and to assure a unified and effective approach to the solutions. Several areas of preclinical investigation were deemed to be necessary before it would be possible to initiate clinical studies. As neither the monomer nor the dimer of sulfhydryl boron hydride is unequivocally preferable at this time, studies on both compounds should be continued until one is proven superior.

  14. Starch-binding domains in the CBM45 family--low-affinity domains from glucan, water dikinase and α-amylase involved in plastidial starch metabolism.

    Science.gov (United States)

    Glaring, Mikkel A; Baumann, Martin J; Abou Hachem, Maher; Nakai, Hiroyuki; Nakai, Natsuko; Santelia, Diana; Sigurskjold, Bent W; Zeeman, Samuel C; Blennow, Andreas; Svensson, Birte

    2011-04-01

    Starch-binding domains are noncatalytic carbohydrate-binding modules that mediate binding to granular starch. The starch-binding domains from the carbohydrate-binding module family 45 (CBM45, http://www.cazy.org) are found as N-terminal tandem repeats in a small number of enzymes, primarily from photosynthesizing organisms. Isolated domains from representatives of each of the two classes of enzyme carrying CBM45-type domains, the Solanum tuberosumα-glucan, water dikinase and the Arabidopsis thaliana plastidial α-amylase 3, were expressed as recombinant proteins and characterized. Differential scanning calorimetry was used to verify the conformational integrity of an isolated CBM45 domain, revealing a surprisingly high thermal stability (T(m) of 84.8 °C). The functionality of CBM45 was demonstrated in planta by yellow/green fluorescent protein fusions and transient expression in tobacco leaves. Affinities for starch and soluble cyclodextrin starch mimics were measured by adsorption assays, surface plasmon resonance and isothermal titration calorimetry analyses. The data indicate that CBM45 binds with an affinity of about two orders of magnitude lower than the classical starch-binding domains from extracellular microbial amylolytic enzymes. This suggests that low-affinity starch-binding domains are a recurring feature in plastidial starch metabolism, and supports the hypothesis that reversible binding, effectuated through low-affinity interaction with starch granules, facilitates dynamic regulation of enzyme activities and, hence, of starch metabolism.

  15. A photo-cleavable biotin affinity tag for the facile release of a photo-crosslinked carbohydrate-binding protein.

    Science.gov (United States)

    Chang, Tsung-Che; Adak, Avijit K; Lin, Ting-Wei; Li, Pei-Jhen; Chen, Yi-Ju; Lai, Chain-Hui; Liang, Chien-Fu; Chen, Yu-Ju; Lin, Chun-Cheng

    2016-03-15

    The use of photo-crosslinking glycoprobes represents a powerful strategy for the covalent capture of labile protein complexes and allows detailed characterization of carbohydrate-mediated interactions. The selective release of target proteins from solid support is a key step in functional proteomics. We envisaged that light activation can be exploited for releasing labeled protein in a dual photo-affinity probe-based strategy. To investigate this possibility, we designed a trifunctional, galactose-based, multivalent glycoprobe for affinity labeling of carbohydrate-binding proteins. The resulting covalent protein-probe adduct is attached to a photo-cleavable biotin affinity tag; the biotin moiety enables specific presentation of the conjugate on streptavidin-coated beads, and the photolabile linker allows the release of the labeled proteins. This dual probe promotes both the labeling and the facile cleavage of the target protein complexes from the solid surfaces and the remainder of the cell lysate in a completely unaltered form, thus eliminating many of the common pitfalls associated with traditional affinity-based purification methods.

  16. Peptide-Based Protein Capture Agents with High Affinity, Selectivity, and Stability as Antibody Replacements in Biodetection Assays

    Science.gov (United States)

    2014-08-01

    The PCC agent oligopeptides are developed against known protein epitopes and can be mass produced using robotic methods. In this work, a PCC agent...are developed against known protein epitopes and can be mass produced using robotic methods. In this work, a PCC agent under development will be...of Anthrax Protective Antigen," ACS Nano , 7(10), 9452-9460 (2013). [16] Life Technologies, "ELISA Protocol (General Guidelines)," <http

  17. Chasing polys: Interdisciplinary affinity and its connection to physics identity

    Science.gov (United States)

    Scott, Tyler D.

    This research is based on two motivations that merge by means of the frameworks of interdisciplinary affinity and physics identity. First, a goal of education is to develop interdisciplinary abilities in students' thinking and work. But an often ignored factor is students interests and beliefs about being interdisciplinary. Thus, this work develops and uses a framework called interdisciplinary affinity. It encompasses students interests in making connections across disciplines and their beliefs about their abilities to make those connections. The second motivation of this research is to better understand how to engage more students with physics. Physics identity describes how a student sees themselves in relation to physics. By understanding how physics identity is developed, researchers and educators can identify factors that increase interest and engagement in physics classrooms. Therefore, physics identity was used in conjunction with interdisciplinary affinity. Using a mixed methods approach, this research used quantitative data to identify the relationships interdisciplinary affinity has with physics identity and the physics classroom. These connections were explored in more detail using a case study of three students in a high school physics class. Results showed significant and positive relationships between interdisciplinary affinity and physics identity, including the individual interest and recognition components of identity. It also identified characteristics of physics classrooms that had a significant, positive relationship with interdisciplinary affinity. The qualitative case study highlighted the importance of student interest to the relationship between interdisciplinary affinity and physics identity. It also identified interest and mastery orientation as key to understanding the link between interdisciplinary affinity and the physics classroom. These results are a positive sign that by understanding interdisciplinary affinity and physics identity

  18. Solution-Processed Nanocrystal Quantum Dot Tandem Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2011-06-03

    Solution-processed tandem solar cells created from nanocrystal quantum dots with size-tuned energy levels are demonstrated. Prototype devices featuring interconnected quantum dot layers of cascaded energy gaps exhibit IR sensitivity and an open circuit voltage, V oc, approaching 1 V. The tandem solar cell performance depends critically on the optical and electrical properties of the interlayer. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Solution-processed nanocrystal quantum dot tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joshua J.; Lim, Yee-Fun [School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States); Wenger, Whitney N.; Hoffman, Rachel S.; Hanrath, Tobias [School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853 (United States); Luria, Justin; Marohn, John A. [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853 (United States); Jasieniak, Jacek [CSIRO Materials Science and Engineering, Bayview Ave, Clayton, Victoria 3168 (Australia)

    2011-07-26

    Solution-processed tandem solar cells created from nanocrystal quantum dots with size-tuned energy levels are demonstrated. Prototype devices featuring interconnected quantum dot layers of cascaded energy gaps exhibit IR sensitivity and an open circuit voltage, V{sub oc}, approaching 1 V. The tandem solar cell performance depends critically on the optical and electrical properties of the interlayer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Electrochemical Affinity Biosensors in Food Safety

    Directory of Open Access Journals (Sweden)

    Susana Campuzano

    2017-02-01

    Full Text Available Safety and quality are key issues of today’s food industry. Since the food chain is becoming more and more complex, powerful analytical methods are required to verify the performance of food safety and quality systems. Indeed, such methods require high sensitivity, selectivity, ability for rapid implementation and capability of automatic screening. Electroanalytical chemistry has, for decades, played a relevant role in food safety and quality assessment, taking more and more significance over time in the solution of analytical problems. At present, the implementation of electrochemical methods in the food is evident. This is in a large part due to the relevant results obtained by combining the attractive advantages of electrochemical transduction strategies (in terms of relatively simple hardware, versatility, interface with automatic logging and feasibility of application outside the laboratory environment with those from biosensors technology. Important examples of enzyme electrochemical biosensors are those dedicated to the determination of glucose, alcohol or cholesterol are important examples. In addition, other types of different electrochemical biosensing approaches have emerged strongly in the last years. Among these, the strategies involving affinity interactions have been shown to possess a large number of applications. Therefore, electrochemical immunosensors and DNA-based biosensors have been widely used to determine major and minor components in foodstuffs, providing sufficient data to evaluate food freshness, the quality of raw materials, or the origin of samples, as well as to determine a variety of compounds at trace levels related to food safety such as micotoxins, allergens, drugs residues or pathogen microorganisms. This review discusses some critical examples of the latest advances in this area, pointing out relevant methodologies related to the measurement techniques, including the use of nanostructured electrodes and

  1. Optimal affine-invariant matching: performance characterization

    Science.gov (United States)

    Costa, Mauro S.; Haralick, Robert M.; Shapiro, Linda G.

    1992-04-01

    The geometric hashing scheme proposed by Lamdan and Wolfson can be very efficient in a model-based matching system, not only in terms of the computational complexity involved, but also in terms of the simplicity of the method. In a recent paper, we discussed errors that can occur with this method due to quantization, stability, symmetry, and noise problems. These errors make the original geometric hashing technique unsuitable for use on the factory floor. Beginning with an explicit noise model, which the original Lamdan and Wolfson technique lacks, we derived an optimal approach that overcomes these problems. We showed that the results obtained with the new algorithm are clearly better than the results from the original method. This paper addresses the performance characterization of the geometric hashing technique, more specifically the affine-invariant point matching, applied to the problem of recognizing and determining the pose of sheet metal parts. The experiments indicate that with a model having 10 to 14 points, with 2 points of the model undetected and 10 extraneous points detected, and with the model points perturbed by Gaussian noise of standard deviation 3 (0.58 of range), the average amount of computation required to obtain an answer is equivalent to trying 11 of the possible three-point bases. The misdetection rate, measured by the percentage of correct bases matches that fail to verify, is 0.9. The percentage of incorrect bases that successfully produced a match that did verify (false alarm rate) is 13. And, finally, 2 of the experiments failed to find a correct match and verify it. Results for experiments with real images are also presented.

  2. Affinity capillary electrophoresis: the theory of electromigration.

    Science.gov (United States)

    Dubský, Pavel; Dvořák, Martin; Ansorge, Martin

    2016-12-01

    We focus on the state-of-the-art theory of electromigration under single and multiple complexation equilibrium. Only 1:1 complexation stoichiometry is discussed because of its unique status in the field of affinity capillary electrophoresis (ACE). First, we summarize the formulas for the effective mobility in various ACE systems as they appeared since the pioneering days in 1992 up to the most recent theories till 2015. Disturbing phenomena that do not alter the mobility of the analyte directly but cause an unexpected peak broadening have been studied only recently and are also discussed in this paper. Second, we turn our attention to the viscosity effects in ACE. Change in the background electrolyte viscosity is unavoidable in ACE but numerous observations scattered throughout the literature have not been reviewed previously. This leads to an uncritical employment of correction factors that may or may not be appropriate in practice. Finally, we consider the ionic strength effects in ACE, too. Limitations of the current theories are also discussed and the tasks identified where open problems still prevail. Graphical Abstract A weak base (A) undergoes an acidic-basic equilibria (in blue) and migrates with an electrophoretic mobility of [Formula: see text]. Simultaneously, it interacts with a selector (sel) while the analyte-selector complex migrates with an electrophoretic mobility of [Formula: see text]. The strength of the interaction (in orange) is governed by the binding constant, K A , and the concentration of the selector, c sel . This all gives the analyte an effective mobility of [Formula: see text] and moves it out of the zero position (EOF; right top insert). The interaction of the positively charged analyte with the neutral selector slows down the analyte with increasing selector concentration (right bottom insert).

  3. Convulsant bicuculline modifies CNS muscarinic receptor affinity

    Directory of Open Access Journals (Sweden)

    Rodríguez de Lores Arnaiz Georgina

    2006-04-01

    Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process

  4. Intragenic tandem repeat variation between Legionella pneumophila strains

    Directory of Open Access Journals (Sweden)

    Jarraud Sophie

    2008-12-01

    Full Text Available Abstract Background Bacterial genomes harbour a large number of tandem repeats, yet the possible phenotypic effects of those found within the coding region of genes are only beginning to be examined. Evidence exists from other organisms that these repeats can be involved in the evolution of new genes, gene regulation, adaptation, resistance to environmental stresses, and avoidance of the immune system. Results In this study, we have investigated the presence and variability in copy number of intragenic tandemly repeated sequences in the genome of Legionella pneumophila, the etiological agent of a severe pneumonia known as Legionnaires' disease. Within the genome of the Philadelphia strain, we have identified 26 intragenic tandem repeat sequences using conservative selection criteria. Of these, seven were "polymorphic" in terms of repeat copy number between a large number of L. pneumophila serogroup 1 strains. These strains were collected from a wide variety of environments and patients in several geographical regions. Within this panel of strains, all but one of these seven genes exhibited statistically different patterns in repeat copy number between samples from different origins (environmental, clinical, and hot springs. Conclusion These results support the hypothesis that intragenic tandem repeats could play a role in virulence and adaptation to different environments. While tandem repeats are an increasingly popular focus of molecular typing studies in prokaryotes, including in L. pneumophila, this study is the first examining the difference in tandem repeat distribution as a function of clinical or environmental origin.

  5. Pharmacokinetic properties of tandem d-peptides designed for treatment of Alzheimer's disease.

    Science.gov (United States)

    Leithold, Leonie H E; Jiang, Nan; Post, Julia; Niemietz, Nicole; Schartmann, Elena; Ziehm, Tamar; Kutzsche, Janine; Shah, N Jon; Breitkreutz, Jörg; Langen, Karl-Josef; Willuweit, Antje; Willbold, Dieter

    2016-06-30

    Peptides are more and more considered for the development of drug candidates. However, they frequently exhibit severe disadvantages such as instability and unfavourable pharmacokinetic properties. Many peptides are rapidly cleared from the organism and oral bioavailabilities as well as in vivo half-lives often remain low. In contrast, some peptides consisting solely of d-enantiomeric amino acid residues were shown to combine promising therapeutic properties with high proteolytic stability and enhanced pharmacokinetic parameters. Recently, we have shown that D3 and RD2 have highly advantageous pharmacokinetic properties. Especially D3 has already proven promising properties suitable for treatment of Alzheimer's disease. Here, we analyse the pharmacokinetic profiles of D3D3 and RD2D3, which are head-to-tail tandem d-peptides built of D3 and its derivative RD2. Both D3D3 and RD2D3 show proteolytic stability in mouse plasma and organ homogenates for at least 24h and in murine and human liver microsomes for 4h. Notwithstanding their high affinity to plasma proteins, both peptides are taken up into the brain following i.v. as well as i.p. administration. Although both peptides contain identical d-amino acid residues, they are arranged in a different sequence order and the peptides show differences in pharmacokinetic properties. After i.p. administration RD2D3 exhibits lower plasma clearance and higher bioavailability than D3D3. We therefore concluded that the amino acid sequence of RD2 leads to more favourable pharmacokinetic properties within the tandem peptide, which underlines the importance of particular sequence motifs, even in short peptides, for the design of further therapeutic d-peptides.

  6. The accelerator neutron source for boron neutron capture therapy

    Science.gov (United States)

    Kasatov, D.; Koshkarev, A.; Kuznetsov, A.; Makarov, A.; Ostreinov, Yu; Shchudlo, I.; Sorokin, I.; Sycheva, T.; Taskaev, S.; Zaidi, L.

    2016-11-01

    The accelerator based epithermal neutron source for Boron Neutron Capture Therapy (BNCT) is proposed, created and used in the Budker Institute of Nuclear Physics. In 2014, with the support of the Russian Science Foundation created the BNCT laboratory for the purpose to the end of 2016 get the neutron flux, suitable for BNCT. For getting 3 mA 2.3 MeV proton beam, was created a new type accelerator - tandem accelerator with vacuum isolation. On this moment, we have a stationary proton beam with 2.3 MeV and current 1.75 mA. Generation of neutrons is carried out by dropping proton beam on to lithium target as a result of threshold reaction 7Li(p,n)7Be. Established facility is a unique scientific installation. It provides a generating of neutron flux, including a monochromatic energy neutrons, gamma radiation, alpha-particles and positrons, and may be used by other research groups for carrying out scientific researches. The article describes an accelerator neutron source, presents and discusses the result of experiments and declares future plans.

  7. Tandem mass spectrometry: analysis of complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, K.E.

    1985-01-01

    Applications of tandem mass spectrometry (MS/MS) for the analysis of complex mixtures results in increased specificity and selectivity by using a variety of reagent gases in both negative and positive ion modes. Natural isotopic abundance ratios were examined in both simple and complex mixtures using parent, daughter and neutral loss scans. MS/MS was also used to discover new compounds. Daughter scans were used to identify seven new alkaloids in a cactus species. Three of these alkaloids were novel compounds, and included the first simple, fully aromatic isoquinoline alkaloids reported in Cactaceae. MS/MS was used to characterize the chemical reaction products of coal in studies designed to probe its macromolecular structure. Negative ion chemical ionization was utilized to study reaction products resulting from the oxidation of coal. Possible structural units in the precursor coal were predicted based on the reaction products identified, aliphatic and aromatic acids and their anhydrides. The MS/MS method was also used to characterize reaction products resulting from coal liquefaction and/or extraction. These studies illustrate the types of problems for which MS/MS is useful. Emphasis has been placed on characterization of complex mixtures by selecting experimental parameters which enhance the information obtained. The value of using MS/MS in conjunction with other analytical techniques as well as the chemical pretreatment is demonstrated.

  8. Wake-induced vibrations in Tandem Cylinders

    Science.gov (United States)

    Mysa, Ravi Chaithanya; Jaiman, Rajeev Kumar

    2015-11-01

    The upstream cylinder is fixed in the tandem cylinders arrangement. The downstream cylinder is placed at a distance of four diameters from the upstream cylinder in the free stream direction and is mounted on a spring. The dynamic response of the downstream cylinder is studied at Reynolds number of 10,000. The transverse displacement amplitude of the downstream cylinder is larger compared to that of single cylinder in the post-lock-in region. The transverse dynamic response of the downstream cylinder in the post-lock-in region is characterized by a dominant low frequency component compared to shed frequency, which is nearer to the structural natural frequency. The interaction of upstream wake with the downstream cylinder is carefully analyzed to understand the introduction of low frequency component in the transverse load along with the shed frequency. We found that the stagnation point moves in proportional to the velocity of the cylinder and is in-phase with the velocity. The low frequency component in the stagnation point movement on the downstream cylinder is sustained by the interaction of upstream wake. The frequencies in the movement of the stagnation point is reflected in the transverse load resulting in large deformation of the cylinder. The authors wish to acknowledge support from A*STAR- SERC and Singapore Maritime Institute.

  9. Actualization of the Tandem-E N Accelerator of the Nuclear Centre of Mexico; Actualizacion del Acelerador Tandem-EN del Centro Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Villasenor S, P.; Aguilera R, E.; Aspiazu F, J.; Fernandez A, J.; Fernandez B, M.; Garcia R, B.; Lopez M, J.; Martinez Q, E.; Mendez G, B.; Moreno B, E.; Murillo O, G.; Policroniades R, R.; Ramirez T, J.; Reynoso V, R.; Varela G, A.; Vega C, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    In this work, the activities are described carried out to change the tubes accelerators and original resistances of the accelerator Tandem-E N of the Nuclear Center, for tubes DOWLISH and resistances again design, both donated ones for ORNL. This way same, the problem is described that imply this changes, and like it was solved by the personnel of the laboratory, without having to appeal to external services, what there is redounded in a considerable increment in the costs. In form preliminary the improvements are described observed after the rehabilitation of the Accelerator. (Author)

  10. The sodium ion affinities of asparagine, glutamine, histidine and arginine

    Science.gov (United States)

    Wang, Ping; Ohanessian, Gilles; Wesdemiotis, Chrys

    2008-01-01

    The sodium ion affinities of the amino acids Asn, Gln, His and Arg have been determined by experimental and computational approaches (for Asn, His and Arg). Na+-bound heterodimers with amino acid and peptide ligands (Pep1, Pep2) were produced by electrospray ionization. From the dissociation kinetics of these Pep1-Na+-Pep2 ions to Pep1-Na+ and Pep2-Na+, determined by collisionally activated dissociation, a ladder of relative affinities was constructed and subsequently converted to absolute affinities by anchoring the relative values to known Na+ affinities. The Na+ affinities of Asn, His and Arg, were calculated at the MP2(full)/6-311+G(2d,2p)//MP2/6-31G(d) level of ab initio theory. The resulting experimental and computed Na+ affinities are in excellent agreement with one another. These results, combined with those of our previous studies, yield the sodium ion affinities of 18 out of the 20 [alpha]-amino acids naturally occurring in peptides and proteins of living systems.

  11. Tetrahydroprotoberberine alkaloids with dopamine and σ receptor affinity.

    Science.gov (United States)

    Gadhiya, Satishkumar; Madapa, Sudharshan; Kurtzman, Thomas; Alberts, Ian L; Ramsey, Steven; Pillarsetty, Nagavara-Kishore; Kalidindi, Teja; Harding, Wayne W

    2016-05-01

    Two series of analogues of the tetrahydroprotoberberine (THPB) alkaloid (±)-stepholidine that (a) contain various alkoxy substituents at the C10 position and, (b) were de-rigidified with respect to (±)-stepholidine, were synthesized and evaluated for affinity at dopamine and σ receptors in order to evaluate effects on D3 and σ2 receptor affinity and selectivity. Small n-alkoxy groups are best tolerated by D3 and σ2 receptors. Among all compounds tested, C10 methoxy and ethoxy analogues (10 and 11 respectively) displayed the highest affinity for σ2 receptors as well as σ2 versus σ1 selectivity and also showed the highest D3 receptor affinity. De-rigidification of stepholidine resulted in decreased affinity at all receptors evaluated; thus the tetracyclic THPB framework is advantageous for affinity at dopamine and σ receptors. Docking of the C10 analogues at the D3 receptor, suggest that an ionic interaction between the protonated nitrogen atom and Asp110, a H-bond interaction between the C2 phenol and Ser192, a H-bond interaction between the C10 phenol and Cys181 as well as hydrophobic interactions of the aryl rings to Phe106 and Phe345, are critical for high affinity of the compounds.

  12. Ebolavirus nucleoprotein C-termini potently attract single domain antibodies enabling monoclonal affinity reagent sandwich assay (MARSA formulation.

    Directory of Open Access Journals (Sweden)

    Laura J Sherwood

    Full Text Available BACKGROUND: Antigen detection assays can play an important part in environmental surveillance and diagnostics for emerging threats. We are interested in accelerating assay formulation; targeting the agents themselves to bypass requirements for a priori genome information or surrogates. Previously, using in vitro affinity reagent selection on Marburg virus we rapidly established monoclonal affinity reagent sandwich assay (MARSA where one recombinant antibody clone was both captor and tracer for polyvalent nucleoprotein (NP. Hypothesizing that the closely related Ebolavirus genus may share the same Achilles' heel, we redirected the scheme to see whether similar assays could be delivered and began to explore their mechanism. METHODS AND FINDINGS: In parallel we selected panels of llama single domain antibodies (sdAb from a semi-synthetic library against Zaire, Sudan, Ivory Coast, and Reston Ebola viruses. Each could perform as both captor and tracer in the same antigen sandwich capture assay thereby forming MARSAs. All sdAb were specific for NP and those tested required the C-terminal domain for recognition. Several clones were cross-reactive, indicating epitope conservation across the Ebolavirus genus. Analysis of two immune shark sdAb revealed they also targeted the C-terminal domain, and could be similarly employed, yet were less sensitive than a comparable llama sdAb despite stemming from immune selections. CONCLUSIONS: The C-terminal domain of Ebolavirus NP is a strong attractant for antibodies and enables sensitive sandwich immunoassays to be rapidly generated using a single antibody clone. The polyvalent nature of nucleocapsid borne NP and display of the C-terminal region likely serves as a bountiful affinity sink during selections, and a highly avid target for subsequent immunoassay capture. Combined with the high degree of amino acid conservation through 37 years and across wide geographies, this domain makes an ideal handle for monoclonal

  13. Novel multiplex format of an extended multilocus variable-number-tandem-repeat analysis of Clostridium difficile correlates with tandem repeat sequence typing.

    Science.gov (United States)

    Jensen, Mie Birgitte Frid; Engberg, Jørgen; Larsson, Jonas T; Olsen, Katharina E P; Torpdahl, Mia

    2015-03-01

    Subtyping of Clostridium difficile is crucial for outbreak investigations. An extended multilocus variable-number tandem-repeat analysis (eMLVA) of 14 variable number tandem repeat (VNTR) loci was validated in multiplex format compatible with a routine typing laboratory and showed excellent concordance with tandem repeat sequence typing (TRST) and high discriminatory power.

  14. Evaluation of Affinity-Tagged Protein Expression Strategies using Local and Global Isotope Ratio Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hervey, IV, William Judson [ORNL; Khalsa-Moyers, Gurusahai K [ORNL; Lankford, Patricia K [ORNL; Owens, Elizabeth T [ORNL; McKeown, Catherine K [ORNL; Lu, Tse-Yuan S [ORNL; Foote, Linda J [ORNL; Morrell-Falvey, Jennifer L [ORNL; McDonald, W Hayes [ORNL; Pelletier, Dale A [ORNL; Hurst, Gregory {Greg} B [ORNL

    2009-01-01

    Protein enrichments of engineered, affinity-tagged (or bait ) fusion proteins with interaction partners are often laden with background, non-specific proteins, due to interactions that occur in vitro as an artifact of the technique. Furthermore, the in vivo expression of the bait protein may itself affect physiology or metabolism. In this study, intrinsic affinity purification challenges were investigated in a model protein complex, DNA-dependent RNA polymerase (RNAP), encompassing chromosome- and plasmid-encoding strategies for bait proteins in two different microbial species: Escherichia coli and Rhodopseudomonas palustris. Isotope ratio measurements of bait protein expression strains relative to native, wild-type strains were performed by liquid chromatography tandem mass spectrometry (LC-MS-MS) to assess bait protein expression strategies in each species. Authentic interacting proteins of RNAP were successfully discerned from artifactual co-isolating proteins by the isotopic differentiation of interactions as random or targeted (I-DIRT) method (A. J. Tackett et al. J. Proteome Res. 2005, 4 (5), 1752-1756). To investigate broader effects of bait protein production in the bacteria, we compared proteomes from strains harboring a plasmid that encodes an affinity-tagged subunit (RpoA) of the RNAP complex with the corresponding wild-type strains using stable isotope metabolic labeling. The ratio of RpoA abundance in plasmid strains versus wild type was 0.8 for R. palustris and 1.7 for E. coli. While most other proteins showed no appreciable difference, proteins significantly increased in abundance in plasmid-encoded bait-expressing strains of both species included the plasmid encoded antibiotic resistance protein, GenR and proteins involved in amino acid biosynthesis. Together, these local, complex-specific and more global, whole proteome isotopic abundance ratio measurements provided a tool for evaluating both in vivo and in vitro effects of plasmid

  15. Affine structures and a tableau model for E_6 crystals

    CERN Document Server

    Jones, Brant

    2009-01-01

    We provide the unique affine crystal structure for type E_6^{(1)} Kirillov-Reshetikhin crystals corresponding to the multiples of fundamental weights s Lambda_1, s Lambda_2, and s Lambda_6 for all s \\geq 1 (in Bourbaki's labeling of the Dynkin nodes, where 2 is the adjoint node). Our methods introduce a generalized tableaux model for classical highest weight crystals of type E and use the order three automorphism of the affine E_6^{(1)} Dynkin diagram. In addition, we provide a conjecture for the affine crystal structure of type E_7^{(1)} Kirillov-Reshetikhin crystals corresponding to the adjoint node.

  16. ODE/IM correspondence and modified affine Toda field equations

    CERN Document Server

    Ito, Katsushi

    2014-01-01

    We study the two-dimensional affine Toda field equations for affine Lie algebra $\\hat{\\mathfrak{g}}$ modified by a conformal transformation and the associated linear equations. In the conformal limit, the associated linear problem reduces to a (pseudo-)differential equation. For classical affine Lie algebra $\\hat{\\mathfrak{g}}$, we obtain a (pseudo-)differential equation corresponding to the Bethe equations for the Langlands dual of the Lie algebra $\\mathfrak{g}$, which were found by Dorey et al. in study of the ODE/IM correspondence.

  17. Affinity Thresholds for Membrane Fusion Triggering by Viral Glycoproteins▿

    OpenAIRE

    Hasegawa, Kosei; Hu, Chunling; Nakamura, Takafumi; Marks, James D.; Russell, Stephen J.; Peng, Kah-Whye

    2007-01-01

    Enveloped viruses trigger membrane fusion to gain entry into cells. The receptor affinities of their attachment proteins vary greatly, from 10−4 M to 10−9 M, but the significance of this is unknown. Using six retargeted measles viruses that bind to Her-2/neu with a 5-log range in affinity, we show that receptor affinity has little impact on viral attachment but is nevertheless a key determinant of infectivity and intercellular fusion. For a given cell surface receptor density, there is an aff...

  18. Volatility Components, Affine Restrictions and Non-Normal Innovations

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Dorian, Christian;

    Recent work by Engle and Lee (1999) shows that allowing for long-run and short-run components greatly enhances a GARCH model's ability fit daily equity return dynamics. Using the risk-neutralization in Duan (1995), we assess the option valuation performance of the Engle-Lee model and compare...... models to four conditionally non-normal versions. As in Hsieh and Ritchken (2005), we find that non-affine models dominate affine models both in terms of fitting return and in terms of option valuation. For the affine models we find strong evidence in favor of the component structure for both returns...

  19. Moment-Based Method to Estimate Image Affine Transform

    Institute of Scientific and Technical Information of China (English)

    FENG Guo-rui; JIANG Ling-ge

    2005-01-01

    The estimation of affine transform is a crucial problem in the image recognition field. This paper resorted to some invariant properties under translation, rotation and scaling, and proposed a simple method to estimate the affine transform kernel of the two-dimensional gray image. Maps, applying to the original, produce some correlative points that can accurately reflect the affine transform feature of the image. Furthermore, unknown variables existing in the kernel of the transform are calculated. The whole scheme only refers to one-order moment,therefore, it has very good stability.

  20. Experimental characterization of the transport phenomena, adsorption, and elution in a protein A affinity monolithic medium.

    Science.gov (United States)

    Herigstad, M Omon; Dimartino, Simone; Boi, Cristiana; Sarti, Giulio C

    2015-08-14

    A commercially available convective interaction media (CIM) Protein A monolithic column was fully characterized in view of its application for the affinity capture of IgG in monoclonal antibody production processes. By means of moment analysis, the interstitial porosity and axial dispersion coefficient were determined. The frontal analysis method of characteristic points was employed, for the first time with monolithic media, to determine the dynamic binding capacity. The effects of the flow rate and pH on the total recovery of polyclonal IgG and elution profile were evaluated. A comparison with literature data for Protein A chromatography beads demonstrate the superior bed utilization of monolithic media, which gave better performance at lower residence times.

  1. Techniques for capturing bighorn sheep lambs

    Science.gov (United States)

    Smith, Joshua B.; Walsh, Daniel P.; Goldstein, Elise J.; Parsons, Zachary D.; Karsch, Rebekah C.; Stiver, Julie R.; Cain, James W.; Raedeke, Kenneth J.; Jenks, Jonathan A.

    2014-01-01

    Low lamb recruitment is a major challenge facing managers attempting to mitigate the decline of bighorn sheep (Ovis canadensis), and investigations into the underlying mechanisms are limited because of the inability to readily capture and monitor bighorn sheep lambs. We evaluated 4 capture techniques for bighorn sheep lambs: 1) hand-capture of lambs from radiocollared adult females fitted with vaginal implant transmitters (VITs), 2) hand-capture of lambs of intensively monitored radiocollared adult females, 3) helicopter net-gunning, and 4) hand-capture of lambs from helicopters. During 2010–2012, we successfully captured 90% of lambs from females that retained VITs to ≤1 day of parturition, although we noted differences in capture rates between an area of high road density in the Black Hills (92–100%) of South Dakota, USA, and less accessible areas of New Mexico (71%), USA. Retention of VITs was 78% with pre-partum expulsion the main cause of failure. We were less likely to capture lambs from females that expelled VITs ≥1 day of parturition (range = 80–83%) or females that were collared without VITs (range = 60–78%). We used helicopter net-gunning at several sites in 1999, 2001–2002, and 2011, and it proved a useful technique; however, at one site, attempts to capture lambs led to lamb predation by golden eagles (Aquila chrysaetos). We attempted helicopter hand-captures at one site in 1999, and they also were successful in certain circumstances and avoided risk of physical trauma from net-gunning; however, application was limited. In areas of low accessibility or if personnel lack the ability to monitor females and/or VITs for extended periods, helicopter capture may provide a viable option for lamb capture.

  2. Radioactive proton capture on {sup 6}He

    Energy Technology Data Exchange (ETDEWEB)

    Sauvan, E.; Marques, F.M. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Wilschut, H.W. [Kernfysich Versneller Instituut, Groningen (Netherlands)

    2001-03-01

    Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction {sup 6}He(p,{gamma}) at 40 MeV. Capture into {sup 7}Li is observed as the strongest channel. In addition, events have been recorded that may be described by quasi-free capture on halo neutron, the {alpha} core and {sup 5}He. The possibility of describing such events by capture into the continuum of {sup 7}Li is also discussed. (authors)

  3. The impact of genome triplication on tandem gene evolution in Brassica rapa

    Directory of Open Access Journals (Sweden)

    Lu eFang

    2012-11-01

    Full Text Available Whole genome duplication (WGD and tandem duplication (TD are both important modes of gene expansion. However, how whole genome duplication influences tandemly duplicated genes is not well studied. We used Brassica rapa, which has undergone an additional genome triplication (WGT and shares a common ancestor with Arabidopsis thaliana, Arabidopsis lyrata and Thellungiella parvula, to investigate the impact of genome triplication on tandem gene evolution. We identified 2,137, 1,569, 1,751 and 1,135 tandem gene arrays in B. rapa, A. thaliana, A. lyrata and T. parvula respectively. Among them, 414 conserved tandem arrays are shared by the 3 species without WGT, which were also considered as existing in the diploid ancestor of B. rapa. Thus, after genome triplication, B. rapa should have 1,242 tandem arrays according to the 414 conserved tandems. Here, we found 400 out of the 414 tandems had at least one syntenic ortholog in the genome of B. rapa. Furthermore, 294 out of the 400 shared syntenic orthologs maintain tandem arrays (more than one gene for each syntenic hit in B. rapa. For the 294 tandem arrays, we obtained 426 copies of syntenic paralogous tandems in the triplicated genome of B. rapa. In this study, we demonstrated that tandem arrays in B. rapa were dramatically fractionated after WGT when compared either to non-tandem genes in the B. rapa genome or to the tandem arrays in closely related species that have not experienced a recent whole-genome polyploidization event.

  4. Design and optimization of a phosphopeptide anchor for specific immobilization of a capture protein on zirconium phosphonate modified supports.

    Science.gov (United States)

    Liu, Hao; Queffélec, Clémence; Charlier, Cathy; Defontaine, Alain; Fateh, Amina; Tellier, Charles; Talham, Daniel R; Bujoli, Bruno

    2014-11-25

    The attachment of affinity proteins onto zirconium phosphonate coated glass slides was investigated by fusing a short phosphorylated peptide sequence at one extremity to enable selective bonding to the active surface via the formation of zirconium phosphate coordinate covalent bonds. In a model study, the binding of short peptides containing zero to four phosphorylated serine units and a biotin end-group was assessed by surface plasmon resonance-enhanced ellipsometry (SPREE) as well as in a microarray format using fluorescence detection of AlexaFluor 647-labeled streptavidin. Significant binding to the zirconated surface was only observed in the case of the phosphopeptides, with the best performance, as judged by streptavidin capture, observed for peptides with three or four phosphorylation sites and when spotted at pH 3. When fusing similar phosphopeptide tags to the affinity protein, the presence of four phosphate groups in the tag allows efficient immobilization of the proteins and efficient capture of their target.

  5. Enrichment and Analysis of Nonenzymatically Glycated Peptides: Boronate Affinity Chromatography Coupled with Electron-Transfer Dissociation Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qibin; Tang, Ning; Brock, Jonathan W.; Mottaz, Heather M.; Ames, Jennifer M.; Baynes, John; Smith, Richard D.; Metz, Thomas O.

    2007-06-01

    Non-enzymatic glycation of peptides and proteins by D-glucose has important implications in the pathogenesis of diabetes mellitus, particularly in the development of diabetic complications. However, no effective high-throughput methods exist for identifying proteins containing this low abundance post-translational modification in bottom-up proteomic studies. In this report, phenylboronate affinity chromatography was used in a two-step enrichment scheme to selectively isolate first glycated proteins and then glycated, tryptic peptides from human serum glycated in vitro. Enriched peptides were subsequently analyzed by alternating electron transfer dissociation (ETD) and collision induced dissociation (CID) tandem mass spectrometry. It was observed that ETD fragmentation mode resulted in a significantly higher number of glycated peptide identifications (87.6% of all identified peptides) versus CID mode (17.0% of all identified peptides), when utilizing dual glycation enrichment on both the protein and peptide level. This study illustrates that phenylboronate affinity chromatography coupled with LC-MS/MS with ETD as the fragmentation mode is an efficient approach for analyses of glycated proteins and can have broad applications in studies of diabetes mellitus.

  6. Synthesis and characterization of pseudo-affinity ligand for penicillin acylase purification.

    Science.gov (United States)

    Keçili, Rüstem; Say, Ridvan; Yavuz, Handan

    2006-11-15

    The aim of this work was to test a chromatographic affinity support containing methacryloyl antipyrine (MAAP) for penicillin acylase (PA) purification by using pure penicillin acylase and crude extract. First, MAAP as a pseudo-specific ligand was synthesized by using methacryloyl chloride and 4-aminoantipyrine. Polymer beads (average size diameter: 40-120 micro m) were prepared by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and MAAP. This approach for the preparation of adsorbent has several advantages over conventional preparation protocols. An expensive and time consuming step in the preparation of adsorbent is immobilization of a ligand to the adsorption matrix. In this procedure, affinity ligand MAAP acts as comonomer without further modification steps. Poly(EGDMA-MAAP) beads were characterized by FTIR, NMR and screen analysis. Elemental analysis of MAAP for nitrogen was estimated as 89.3 micro mol/g. The prepared adsorbent was then used for the capture of penicillin acylase in batch system. The maximum penicillin acylase adsorption capacity of the poly(EGDMA-MAAP) beads was found to be 82.2 mg/g at pH 5.0. Chromatography with crude feedstock resulted in 23.2-fold purification and 93% recovery with 1.0 M NaOH.

  7. Combining transcription factor binding affinities with open-chromatin data for accurate gene expression prediction

    Science.gov (United States)

    Schmidt, Florian; Gasparoni, Nina; Gasparoni, Gilles; Gianmoena, Kathrin; Cadenas, Cristina; Polansky, Julia K.; Ebert, Peter; Nordström, Karl; Barann, Matthias; Sinha, Anupam; Fröhler, Sebastian; Xiong, Jieyi; Dehghani Amirabad, Azim; Behjati Ardakani, Fatemeh; Hutter, Barbara; Zipprich, Gideon; Felder, Bärbel; Eils, Jürgen; Brors, Benedikt; Chen, Wei; Hengstler, Jan G.; Hamann, Alf; Lengauer, Thomas; Rosenstiel, Philip; Walter, Jörn; Schulz, Marcel H.

    2017-01-01

    The binding and contribution of transcription factors (TF) to cell specific gene expression is often deduced from open-chromatin measurements to avoid costly TF ChIP-seq assays. Thus, it is important to develop computational methods for accurate TF binding prediction in open-chromatin regions (OCRs). Here, we report a novel segmentation-based method, TEPIC, to predict TF binding by combining sets of OCRs with position weight matrices. TEPIC can be applied to various open-chromatin data, e.g. DNaseI-seq and NOMe-seq. Additionally, Histone-Marks (HMs) can be used to identify candidate TF binding sites. TEPIC computes TF affinities and uses open-chromatin/HM signal intensity as quantitative measures of TF binding strength. Using machine learning, we find low affinity binding sites to improve our ability to explain gene expression variability compared to the standard presence/absence classification of binding sites. Further, we show that both footprints and peaks capture essential TF binding events and lead to a good prediction performance. In our application, gene-based scores computed by TEPIC with one open-chromatin assay nearly reach the quality of several TF ChIP-seq data sets. Finally, these scores correctly predict known transcriptional regulators as illustrated by the application to novel DNaseI-seq and NOMe-seq data for primary human hepatocytes and CD4+ T-cells, respectively. PMID:27899623

  8. In-column ATR-FTIR spectroscopy to monitor affinity chromatography purification of monoclonal antibodies.

    Science.gov (United States)

    Boulet-Audet, Maxime; Kazarian, Sergei G; Byrne, Bernadette

    2016-07-29

    In recent years many monoclonal antibodies (mAb) have entered the biotherapeutics market, offering new treatments for chronic and life-threatening diseases. Protein A resin captures monoclonal antibody (mAb) effectively, but the binding capacity decays over repeated purification cycles. On an industrial scale, replacing fouled Protein A affinity chromatography resin accounts for a large proportion of the raw material cost. Cleaning-in-place (CIP) procedures were developed to extend Protein A resin lifespan, but chromatograms cannot reliably quantify any remaining contaminants over repeated cycles. To study resin fouling in situ, we coupled affinity chromatography and Fourier transform infrared (FTIR) spectroscopy for the first time, by embedding an attenuated total reflection (ATR) sensor inside a micro-scale column while measuring the UV 280 nm and conductivity. Our approach quantified the in-column protein concentration in the resin bed and determined protein conformation. Our results show that Protein A ligand leached during CIP. We also found that host cell proteins bound to the Protein A resin even more strongly than mAbs and that typical CIP conditions do not remove all fouling contaminants. The insights derived from in-column ATR-FTIR spectroscopic monitoring could contribute to mAb purification quality assurance as well as guide the development of more effective CIP conditions to optimise resin lifespan.

  9. Preparation and evaluation of spore-specific affinity- augmented bio-imprinted beads

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Scott D.; Mong, Gary M.; Ozanich, Rich M.; Mclean, Jeffrey S.; Goodwin, Shannon M.; Valentine, Nancy B.; Fredrickson, Jim K.

    2006-09-01

    The procedures previously described for imprinting bead surfaces with bacteria were applied to create novel affinity-augmented bacterial spore-imprinted beads. The imprinted beads are intended as a front-end spore capture/concentration stage of an integrated biological detection system. Our approach involves embedding bead surfaces with Bacillus thuringiensis kurstaki (Bt) spores (as a surrogate for Bacillus anthracis) during synthesis. Subsequent steps involved lithographic deactivation using a perfluoroether, spore removal to create imprint sites, and coating imprints with the lectin, concanavalin A, to provide general affinity. The synthesis of the intended material with the desired imprints was verified by scanning electron and confocal laser-scanning microscopy. The material was evaluated using spore-binding assays with either Bt or Bacillus subtilis (Bs) spores. The binding assays indicated strong spore-binding capability and a robust imprinting effect that accounted for 25 percent additional binding over nonimprinted controls. The binding assay results also indicated that further refinement of the surface deactivation procedure would enhance the performance of the imprinted substrate.

  10. Removal of PCR error products and unincorporated primers by metal-chelate affinity chromatography.

    Directory of Open Access Journals (Sweden)

    Indhu Kanakaraj

    Full Text Available Immobilized Metal Affinity Chromatography (IMAC has been used for decades to purify proteins on the basis of amino acid content, especially surface-exposed histidines and "histidine tags" genetically added to recombinant proteins. We and others have extended the use of IMAC to purification of nucleic acids via interactions with the nucleotide bases, especially purines, of single-stranded RNA and DNA. We also have demonstrated the purification of plasmid DNA from contaminating genomic DNA by IMAC capture of selectively-denatured genomic DNA. Here we describe an efficient method of purifying PCR products by specifically removing error products, excess primers, and unincorporated dNTPs from PCR product mixtures using flow-through metal-chelate affinity adsorption. By flowing a PCR product mixture through a Cu(2+-iminodiacetic acid (IDA agarose spin column, 94-99% of the dNTPs and nearly all the primers can be removed. Many of the error products commonly formed by Taq polymerase also are removed. Sequencing of the IMAC-processed PCR product gave base-calling accuracy comparable to that obtained with a commercial PCR product purification method. The results show that IMAC matrices (specifically Cu(2+-IDA agarose can be used for the purification of PCR products. Due to the generality of the base-specific mechanism of adsorption, IMAC matrices may also be used in the purification of oligonucleotides, cDNA, mRNA and micro RNAs.

  11. In-column ATR-FTIR spectroscopy to monitor affinity chromatography purification of monoclonal antibodies

    Science.gov (United States)

    Boulet-Audet, Maxime; Kazarian, Sergei G.; Byrne, Bernadette

    2016-07-01

    In recent years many monoclonal antibodies (mAb) have entered the biotherapeutics market, offering new treatments for chronic and life-threatening diseases. Protein A resin captures monoclonal antibody (mAb) effectively, but the binding capacity decays over repeated purification cycles. On an industrial scale, replacing fouled Protein A affinity chromatography resin accounts for a large proportion of the raw material cost. Cleaning-in-place (CIP) procedures were developed to extend Protein A resin lifespan, but chromatograms cannot reliably quantify any remaining contaminants over repeated cycles. To study resin fouling in situ, we coupled affinity chromatography and Fourier transform infrared (FTIR) spectroscopy for the first time, by embedding an attenuated total reflection (ATR) sensor inside a micro-scale column while measuring the UV 280 nm and conductivity. Our approach quantified the in-column protein concentration in the resin bed and determined protein conformation. Our results show that Protein A ligand leached during CIP. We also found that host cell proteins bound to the Protein A resin even more strongly than mAbs and that typical CIP conditions do not remove all fouling contaminants. The insights derived from in-column ATR-FTIR spectroscopic monitoring could contribute to mAb purification quality assurance as well as guide the development of more effective CIP conditions to optimise resin lifespan.

  12. Cellulose affinity purification of fusion proteins tagged with fungal family 1 cellulose-binding domain.

    Science.gov (United States)

    Sugimoto, Naohisa; Igarashi, Kiyohiko; Samejima, Masahiro

    2012-04-01

    N- or C-terminal fusions of red-fluorescent protein (RFP) with various fungal cellulose-binding domains (CBDs) belonging to carbohydrate binding module (CBM) family 1 were expressed in a Pichia pastoris expression system, and the resulting fusion proteins were used to examine the feasibility of large-scale affinity purification of CBD-tagged proteins on cellulose columns. We found that RFP fused with CBD from Trichoderma reesei CBHI (CBD(Tr)(CBHI)) was expressed at up to 1.2g/l in the culture filtrate, which could be directly injected into the cellulose column. The fusion protein was tightly adsorbed on the cellulose column in the presence of a sufficient amount of ammonium sulfate and was efficiently eluted with pure water. Bovine serum albumin (BSA) was not captured under these conditions, whereas both BSA and the fusion protein were adsorbed on a phenyl column, indicating that the cellulose column can be used for the purification of not only hydrophilic proteins but also for hydrophobic proteins. Recovery of various fusion proteins exceeded 80%. Our results indicate that protein purification by expression of a target protein as a fusion with a fungal family 1 CBD tag in a yeast expression system, followed by affinity purification on a cellulose column, is simple, effective and easily scalable.

  13. Combining transcription factor binding affinities with open-chromatin data for accurate gene expression prediction.

    Science.gov (United States)

    Schmidt, Florian; Gasparoni, Nina; Gasparoni, Gilles; Gianmoena, Kathrin; Cadenas, Cristina; Polansky, Julia K; Ebert, Peter; Nordström, Karl; Barann, Matthias; Sinha, Anupam; Fröhler, Sebastian; Xiong, Jieyi; Dehghani Amirabad, Azim; Behjati Ardakani, Fatemeh; Hutter, Barbara; Zipprich, Gideon; Felder, Bärbel; Eils, Jürgen; Brors, Benedikt; Chen, Wei; Hengstler, Jan G; Hamann, Alf; Lengauer, Thomas; Rosenstiel, Philip; Walter, Jörn; Schulz, Marcel H

    2017-01-09

    The binding and contribution of transcription factors (TF) to cell specific gene expression is often deduced from open-chromatin measurements to avoid costly TF ChIP-seq assays. Thus, it is important to develop computational methods for accurate TF binding prediction in open-chromatin regions (OCRs). Here, we report a novel segmentation-based method, TEPIC, to predict TF binding by combining sets of OCRs with position weight matrices. TEPIC can be applied to various open-chromatin data, e.g. DNaseI-seq and NOMe-seq. Additionally, Histone-Marks (HMs) can be used to identify candidate TF binding sites. TEPIC computes TF affinities and uses open-chromatin/HM signal intensity as quantitative measures of TF binding strength. Using machine learning, we find low affinity binding sites to improve our ability to explain gene expression variability compared to the standard presence/absence classification of binding sites. Further, we show that both footprints and peaks capture essential TF binding events and lead to a good prediction performance. In our application, gene-based scores computed by TEPIC with one open-chromatin assay nearly reach the quality of several TF ChIP-seq data sets. Finally, these scores correctly predict known transcriptional regulators as illustrated by the application to novel DNaseI-seq and NOMe-seq data for primary human hepatocytes and CD4+ T-cells, respectively.

  14. Accelerator tube construction and characterization for a tandem-electrostatic-quadrupole for accelerator-based boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cartelli, D.; Thatar Vento, V. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Av Rivadavia 1917 (1033), Buenos Aires (Argentina); Castell, W. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina); Di Paolo, H. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Kesque, J.M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina); Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Av Rivadavia 1917 (1033), Buenos Aires (Argentina); Valda, A.A. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina)

    2011-12-15

    The accelerator tubes are essential components of the accelerator. Their function is to transport and accelerate a very intense proton or deuteron beam through the machine, from the ion source to the neutron production target, without significant losses. In this contribution, we discuss materials selected for the tube construction, the procedures used for their assembly and the testing performed to meet the stringent requirements to which it is subjected.

  15. Direct binding of specific AUF1 isoforms to tandem zinc finger domains of tristetraprolin (TTP) family proteins.

    Science.gov (United States)

    Kedar, Vishram P; Zucconi, Beth E; Wilson, Gerald M; Blackshear, Perry J

    2012-02-17

    Tristetraprolin (TTP) is the prototype of a family of CCCH tandem zinc finger proteins that can bind to AU-rich elements in mRNAs and promote their decay. TTP binds to mRNA through its central tandem zinc finger domain; it then promotes mRNA deadenylation, considered to be the rate-limiting step in eukaryotic mRNA decay. We found that TTP and its related family members could bind to certain isoforms of another AU-rich element-binding protein, HNRNPD/AUF1, as well as a related protein, laAUF1. The interaction domain within AUF1p45 appeared to be a C-terminal "GY" region, and the interaction domain within TTP was the tandem zinc finger domain. Surprisingly, binding of AUF1p45 to TTP occurred even with TTP mutants that lacked RNA binding activity. In cell extracts, binding of AUF1p45 to TTP potentiated TTP binding to ARE-containing RNA probes, as determined by RNA gel shift assays; AUF1p45 did not bind to the RNA probes under these conditions. Using purified, recombinant proteins and a synthetic RNA target in FRET assays, we demonstrated that AUF1p45, but not AUF1p37, increased TTP binding affinity for RNA ∼5-fold. These data suggest that certain isoforms of AUF1 can serve as "co-activators" of TTP family protein binding to RNA. The results raise interesting questions about the ability of AUF1 isoforms to regulate the mRNA binding and decay-promoting activities of TTP and its family members as well as the ability of AUF1 proteins to serve as possible physical links between TTP and other mRNA decay proteins and structures.

  16. Taking Advantage: High Affinity B cells in the Germinal Center Have Lower Death Rates, But Similar Rates of Division Compared to Low Affinity Cells1

    OpenAIRE

    2009-01-01

    B lymphocytes producing high affinity antibodies (Abs) are critical for protection from extracellular pathogens, such as bacteria and parasites. The process by which high affinity B cells are selected during the immune response has never been elucidated. Though it has been shown that high affinity cells directly outcompete low affinity cells in the germinal center (GC)2, whether there are also intrinsic differences between these cells has not been addressed. It could be that higher affinity c...

  17. Dirac equation in gauge and affine-metric gravitation theories

    CERN Document Server

    Giachetta, G

    1995-01-01

    We show that the covariant derivative of Dirac fermion fields in the presence of a general linear connection on a world manifold is universal for Einstein's, gauge and affine-metric gravitation theories.

  18. Elective affinities and economic thought: 1870-1914

    Directory of Open Access Journals (Sweden)

    João Antônio de Paula

    2006-01-01

    Full Text Available This article seeks to demonstrate that the concept of "elective affinities" can be applied to the relations between economic thought, literature, and philosophy. Emphasis is given to Institutionalist thought, the German historical school, and neoclassical thought.

  19. REFINABLE DISTRIBUTIONS SUPPORTED ON SELF-AFFINE TILES

    Institute of Scientific and Technical Information of China (English)

    DaiXinrong

    2002-01-01

    In this paper,some conditions which assure the compactly supported refinable distributions supported on a self-affine tile to be Lebesgue-Stieltjes measures or absolutely continuous measures with respect to Lebesgue-Stieltjes measures are given.

  20. ASIFT: An Algorithm for Fully Affine Invariant Comparison

    Directory of Open Access Journals (Sweden)

    Guoshen Yu

    2011-02-01

    Full Text Available If a physical object has a smooth or piecewise smooth boundary, its images obtained by cameras in varying positions undergo smooth apparent deformations. These deformations are locally well approximated by affine transforms of the image plane. In consequence the solid object recognition problem has often been led back to the computation of affine invariant image local features. The similarity invariance (invariance to translation, rotation, and zoom is dealt with rigorously by the SIFT method The method illustrated and demonstrated in this work, Affine-SIFT (ASIFT, simulates a set of sample views of the initial images, obtainable by varying the two camera axis orientation parameters, namely the latitude and the longitude angles, which are not treated by the SIFT method. Then it applies the SIFT method itself to all images thus generated. Thus, ASIFT covers effectively all six parameters of the affine transform.

  1. A thermodynamic approach to the affinity optimization of drug candidates.

    Science.gov (United States)

    Freire, Ernesto

    2009-11-01

    High throughput screening and other techniques commonly used to identify lead candidates for drug development usually yield compounds with binding affinities to their intended targets in the mid-micromolar range. The affinity of these molecules needs to be improved by several orders of magnitude before they become viable drug candidates. Traditionally, this task has been accomplished by establishing structure activity relationships to guide chemical modifications and improve the binding affinity of the compounds. As the binding affinity is a function of two quantities, the binding enthalpy and the binding entropy, it is evident that a more efficient optimization would be accomplished if both quantities were considered and improved simultaneously. Here, an optimization algorithm based upon enthalpic and entropic information generated by Isothermal Titration Calorimetry is presented.

  2. Aluminum-based water treatment residual use in a constructed wetland for capturing urban runoff phosphorus: Column study

    Science.gov (United States)

    Aluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus. In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 year...

  3. Some Inequalities for Lp-mixed Affine Surface Area

    Institute of Scientific and Technical Information of China (English)

    ZHU Xian-yang

    2012-01-01

    In this paper,the concepts of the ith Lp-mixed affine surface area and Lp-polar curvature images are introduced,some new inequalities connecting these new notions with Lp-centroid bodies and p-Blaschke bodies are showed.Moreover,a Blaschke-Santaló type inequality for Lp-mixed affine surface area is established.Our results also imply the similar to the inequalities for Marcus-Lopes,Bergstrom and Ky Fan.

  4. Affinity purification of sequence-specific DNA binding proteins.

    OpenAIRE

    1986-01-01

    We describe a method for affinity purification of sequence-specific DNA binding proteins that is fast and effective. Complementary chemically synthesized oligodeoxynucleotides that contain a recognition site for a sequence-specific DNA binding protein are annealed and ligated to give oligomers. This DNA is then covalently coupled to Sepharose CL-2B with cyanogen bromide to yield the affinity resin. A partially purified protein fraction is combined with competitor DNA and subsequently passed t...

  5. Affine A(1)3 N = 2 Monopole as the D Module and Affine ADHMN Sheaf

    Institute of Scientific and Technical Information of China (English)

    SONG Xiao-Shu; HOU Bo-Yu; GUO Yun-Dong; HOU Bo-Yuan; LING-HU Rong-Feng; L(U) Bing; CHENG Xin-Lu; YANG Xiang-Dong

    2008-01-01

    A Higgs-Yang-Mills monopole scattering spherical symmetrically Mong light cones is given. The left incoming anti-self-dual α plane fields are holomorphic, but the right outgoing SD fl plane fields are antiholomorphic, meanwhile the diffeomorphism symmetry is preserved with mutual inverse a/fine rapidity parameters μ and μ-1. The Dirac wave function scattering in this background also factorized respectively into the (anti)holomorphic amplitudes. The holomorphic anomaly is realized by the center term of a quasi Hopf algebra corresponding to an integrable conformal a/fine massive field. We find explicit Nahm transformation matrix (Fourier-Mukai transformation) between the Higgs YM BPS (fiat) bundles (D modules) and the affinized blow up ADHMN twistors (perverse sheafs). Thus we establish the algebra for the 't Hooft Hecke operators in the Hecke correspondence of the geometric Langfands program.

  6. Test of the Tandem transmission at low terminal voltages

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Blumenthal, D.; Gehring, J. [and others

    1995-08-01

    For a planned experiment with {sup 18}F beams at energies below 1 MeV/u the transmission of the Tandem-Linac system was investigated. The energies required in the experiment are typically around 600 keV/u, which for the most abundant charge states for F(4{sup +}) corresponds to terminal voltages between 2-3 MV. We studied the transmission from the source to the tandem accelerator and to the spectrograph in area II with {sup 18}O and {sup 19}F beams using two different approaches. In the first method only the tandem accelerator was used producing a 14-MeV DC {sup 18}O beam. In the second method a pulsed beam was accelerated to 33 MeV with the tandem accelerator followed by deceleration to 14 MeV with the first 9 resonators of ATLAS. The total transmission from ion source to target was in both cases about 10%. Because of the smaller complexity we used the first method for the {sup 18}F experiment. In future runs we are planning to use the electrostatic lens in the terminal of the tandem to improve the overall transmission.

  7. High-Efficiency Polycrystalline Thin Film Tandem Solar Cells.

    Science.gov (United States)

    Kranz, Lukas; Abate, Antonio; Feurer, Thomas; Fu, Fan; Avancini, Enrico; Löckinger, Johannes; Reinhard, Patrick; Zakeeruddin, Shaik M; Grätzel, Michael; Buecheler, Stephan; Tiwari, Ayodhya N

    2015-07-16

    A promising way to enhance the efficiency of CIGS solar cells is by combining them with perovskite solar cells in tandem devices. However, so far, such tandem devices had limited efficiency due to challenges in developing NIR-transparent perovskite top cells, which allow photons with energy below the perovskite band gap to be transmitted to the bottom cell. Here, a process for the fabrication of NIR-transparent perovskite solar cells is presented, which enables power conversion efficiencies up to 12.1% combined with an average sub-band gap transmission of 71% for photons with wavelength between 800 and 1000 nm. The combination of a NIR-transparent perovskite top cell with a CIGS bottom cell enabled a tandem device with 19.5% efficiency, which is the highest reported efficiency for a polycrystalline thin film tandem solar cell. Future developments of perovskite/CIGS tandem devices are discussed and prospects for devices with efficiency toward and above 27% are given.

  8. Affinity Solvents for Intensified Organics Extraction: Development Challenges and Prospects

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In most organics extraction processes, the commonly used solvents employ solely physical interactions. Therefore, for the recovery and purification of products from complex mixtures, the selectivity and/or capacity of classical solvents towards the desired solutes is usually insufficient, enforcing the need for complex and thus expensive separation schemes. Significant simplification and cost-reduction can be achieved when affinity solvents would be available that are able to recognize the solutes of interest by their molecular structure. The main development challenges to establish such affinity solvents are: Selection and incorporation of molecular recognition and complexation capabilities; Evaluation of extraction capabilities; Efficient recovery and recycling of the affinity solvents; Implementation in industrial extraction equipment. This paper presents how these development challenges are addressed at the University of Twente, going all the way from affinity solvent design and synthesis, via high throughput screening and characterization up to pilot plant evaluation. Essential in the successful development of affinity solvents are structural cooperations with molecular chemists and custom synthesis companies for their design and synthesis. The various aspects are illustrated by several examples where newly developed environmentally benign affinity solvents appeared able to create major breakthroughs. The applications addressed involve oxygenates, sugars, and pharmaceutical ingredients, such as optical isomers and biomolecules.

  9. High affinity ligands for 'diazepam-insensitive' benzodiazepine receptors.

    Science.gov (United States)

    Wong, G; Skolnick, P

    1992-01-14

    Structurally diverse compounds have been shown to possess high affinities for benzodiazepine receptors in their 'diazepam-sensitive' (DS) conformations. In contrast, only the imidazobenzodiazepinone Ro 15-4513 has been shown to exhibit a high affinity for the 'diazepam-insensitive' (DI) conformation of benzodiazepine receptors. We examined a series of 1,4-diazepines containing one or more annelated ring systems for their affinities at DI and DS benzodiazepine receptors, several 1,4-diazepinone carboxylates including Ro 19-4603, Ro 16-6028 and Ro 15-3505 were found to possess high affinities (Ki approximately 2.6-20 nM) for DI. Nonetheless, among the ligands examined, Ro 15-4513 was the only substance with a DI/DS potency ratio approximately 1; other substances had ratios ranging from 13 to greater than 1000. Ligands with high to moderate affinities at DI were previously classified as partial agonists, antagonists, or partial inverse agonists at DS benzodiazepine receptors, but behaved as 'GABA neutral' (antagonist) substances at DI. The identification of several additional high affinity ligands at DI benzodiazepine receptors may be helpful in elucidating the pharmacological and physiological importance of these sites.

  10. Quantitative screening of yeast surface-displayed polypeptide libraries by magnetic bead capture.

    Science.gov (United States)

    Yeung, Yik A; Wittrup, K Dane

    2002-01-01

    Magnetic bead capture is demonstrated here to be a feasible alternative for quantitative screening of favorable mutants from a cell-displayed polypeptide library. Flow cytometric sorting with fluorescent probes has been employed previously for high throughput screening for either novel binders or improved mutants. However, many laboratories do not have ready access to this technology as a result of the limited availability and high cost of cytometers, restricting the use of cell-displayed libraries. Using streptavidin-coated magnetic beads and biotinylated ligands, an alternative approach to cell-based library screening for improved mutants was developed. Magnetic bead capture probability of labeled cells is shown to be closely correlated with the surface ligand density. A single-pass enrichment ratio of 9400 +/- 1800-fold, at the expense of 85 +/- 6% binder losses, is achieved from screening a library that contains one antibody-displaying cell (binder) in 1.1 x 10(5) nondisplaying cells. Additionally, kinetic screening for an initial high affinity to low affinity (7.7-fold lower) mutant ratio of 1:95,000, the magnetic bead capture method attains a single-pass enrichment ratio of 600 +/- 200-fold with a 75 +/- 24% probability of loss for the higher affinity mutant. The observed high loss probabilities can be straightforwardly compensated for by library oversampling, given the inherently parallel nature of the screen. Overall, these results demonstrate that magnetic beads are capable of quantitatively screening for novel binders and improved mutants. The described methods are directly analogous to procedures in common use for phage display and should lower the barriers to entry for use of cell surface display libraries.

  11. Experience machines : Capturing and retrieving personal content

    NARCIS (Netherlands)

    Werkhoven, P.

    2005-01-01

    Fundamental to human existence is the ability to capture, memorise and retrieve personal experiences and to share them with others. Can systems help us to capture and retrieve experiences? After motors have supplemented our muscles and sensors have supplemented our senses, emerging computer systems

  12. Visual Field Asymmetry in Attentional Capture

    Science.gov (United States)

    Du, Feng; Abrams, Richard A.

    2010-01-01

    The present study examined the spatial distribution of involuntary attentional capture over the two visual hemi-fields. A new experiment, and an analysis of three previous experiments showed that distractors in the left visual field that matched a sought-for target in color produced a much larger capture effect than identical distractors in the…

  13. Radiative proton capture on He-6

    NARCIS (Netherlands)

    Sauvan, E; Marques, FM; Wilschut, HW; Orr, NA; Angelique, JC; Borcea, C; Catford, WN; Clarke, NM; Descouvemont, P; Diaz, J; Grevy, S; Kugler, A; Kravchuk, [No Value; Labiche, M; Le Brun, C; Lienard, E; Lohner, H; Mittig, W; Ostendorf, RW; Pietri, S; Roussel-Chomaz, P; Saint Laurent, MG; Savajols, H; Wagner, [No Value; Yahlali, N

    2001-01-01

    Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction He-6(p, gamma) at 40 MeV. Capture into Li-7 is observed as the strongest channel. In addition, events have been recorded

  14. Screen captures to support switching attention

    NARCIS (Netherlands)

    Gellevij, Mark; Meij, van der Hans

    2002-01-01

    The study set out to validate the supportive role of screen captures for switching attention. Forty-two participants learned how to work with Microsoft Excel with a paper manual. There were three types of manuals: a textual manual, a visual manual with full-screen captures, and a visual manual with

  15. Seamless presentation capture, indexing, and management

    Science.gov (United States)

    Hilbert, David M.; Cooper, Matthew; Denoue, Laurent; Adcock, John; Billsus, Daniel

    2005-10-01

    Technology abounds for capturing presentations. However, no simple solution exists that is completely automatic. ProjectorBox is a "zero user interaction" appliance that automatically captures, indexes, and manages presentation multimedia. It operates continuously to record the RGB information sent from presentation devices, such as a presenter's laptop, to display devices, such as a projector. It seamlessly captures high-resolution slide images, text and audio. It requires no operator, specialized software, or changes to current presentation practice. Automatic media analysis is used to detect presentation content and segment presentations. The analysis substantially enhances the web-based user interface for browsing, searching, and exporting captured presentations. ProjectorBox has been in use for over a year in our corporate conference room, and has been deployed in two universities. Our goal is to develop automatic capture services that address both corporate and educational needs.

  16. Capture of Trojans by Jumping Jupiter

    CERN Document Server

    Nesvorny, David; Morbidelli, Alessandro

    2013-01-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ~5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the ...

  17. Encapsulated liquid sorbents for carbon dioxide capture.

    Science.gov (United States)

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-02-05

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  18. Counter-Rotating Tandem Motor Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger

  19. Dosimetric comparison of tandem and Ovoids vs. tandem and ring for intracavitary gynecologic applications.

    Science.gov (United States)

    Levin, Daphne; Menhel, Janna; Rabin, Tanya; Pfeffer, M Raphael; Symon, Zvi

    2008-01-01

    We evaluated dosimetric differences in tandem and ovoid (TO) and tandem and ring (TR) gynecologic brachytherapy applicators. Seventeen patients with cervical cancer (Stages II-IV) receiving 3 high-dose-rate (HDR) brachytherapy applications (both TO and TR) were studied. Patients underwent computed tomography (CT) scans with contrast in bladder, and were prescribed 8 Gy to ICRU points A, with additional optimization goals of maintaining the pear-shaped dose distribution and minimizing bladder and rectum doses. Bladder and rectum point doses, mean, and maximum doses were calculated. Total treatment time and volumes treated to 95%, 85%, 50%, and 20% or the prescription dose were compared. There were no significant differences between TO and TR applicators in doses to prescription points or critical organs. However, there were significant differences (p < 0.001) between the applicators in treated volumes and total treatment time. The TO treated larger volumes over a longer time. Within each patient, when the applicators were compared, treated volumes were also found to be significantly different (p < 0.01, chi(2)). Our results demonstrate that the 2 applicators, while delivering the prescribed dose to points A and keeping critical organ doses below tolerance, treat significantly different volumes. It is unclear if this difference is clinically meaningful. TO applicators may be treating surrounding healthy tissue unnecessarily, or TR applicators may be underdosing tumor tissue. Further investigation with appropriate imaging modalities is required for accurate delineation of target volumes. Clearly, the TO and TR are not identical, and should not be used interchangeably without further study.

  20. Flatness and Profile Integration Control Model for Tandem Cold Mills

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Using the effective matrix methods of flatness and profile control synthetically, the flatness and profile in- tegration control scheme for tandem cold mills is built in order to increase flatness and profile control precision of tan- dem cold mills. Corresponding control strategies are adopted for various control objectives of different stands and the coordination control strategies of various stands are given, which makes the on-line flatness control cooperate with on-line profile control and implements the parallel control of different stands. According to the measured flatness and profile data of some 1550 mm tandem cold mills, the control scheme is verified and the result indicates that the scheme has high flatness and profile control precision with steady and reliable control process. A new way and method is supplied for researching shade control of tandem cold mills.

  1. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  2. Highly Loaded Fan by Using Tandem Cascade Rotor Blade

    Science.gov (United States)

    Hasegawa, Hiroaki; Suga, Shinya; Matsuoka, Akinori

    For axial flow compressors and fans in the aircraft engines higher pressure ratio is required in order to attain the high thrust engines. In this study, the fan with the tandem cascades was introduced to increase the fan pressure ratio. The use of tandem cascades in the fan allows savings in length and weight and therefore a compact fan could be built. The design of fan with tandem cascades and the fan testing were carried out to develop the high pressure ratio fan for the Air Turbo Ramjet (ATR) propulsion system. The ATR is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds. In particular, high fan pressure ratio contributes to increase the engine thrust during subsonic flight at which the engine does not make use of ram effect. The results of the fan testing indicate that the pressure ratio of 2.2 is achieved in single stage fan.

  3. A periodic table of symmetric tandem mismatches in RNA.

    Science.gov (United States)

    Wu, M; McDowell, J A; Turner, D H

    1995-03-14

    The stabilities and structures of a series of RNA octamers containing symmetric tandem mismatches were studied by UV melting and imino proton NMR. The free energy increments for tandem mismatch formation are found to depend upon both mismatch sequence and adjacent base pairs. The observed sequence dependence of tandem mismatch stability is UGGU > GUUG > GAAG > or = AGGA > UUUU > CAAC > or = CUUC approximately UCCU approximately CCCC approximately ACCA approximately AAAA, and the closing base pair dependence is 5'G3'C > 5'C3'G > 5'U3'A approximately 5'A3'U. These results differ from expectations based on models used in RNA folding algorithms and from the sequence dependence observed for folding of RNA hairpins. Imino proton NMR results indicate the sequence dependence is partially due to hydrogen bonding within mismatches.

  4. Structural plasticity of methyllysine recognition by the tandem Tudor domain of 53BP1

    Science.gov (United States)

    Tong, Qiong; Cui, Gaofeng; Botuyan, Maria Victoria; Rothbart, Scott B.; Hayashi, Ryo; Musselman, Catherine A.; Singh, Namit; Appella, Ettore; Strahl, Brian D.; Mer, Georges; Kutateladze, Tatiana G.

    2014-01-01

    SUMMARY p53 is dynamically regulated through various posttranslational modifications (PTMs), which differentially modulate its function and stability. The dimethylated marks p53K370me2 and p53K382me2 are associated with p53 activation or stabilization and both are recognized by the tandem Tudor domain (TTD) of 53BP1, a p53 co-factor. Here we detail the molecular mechanisms for the recognition of p53K370me2 and p53K382me2 by 53BP1. The solution structures of TTD in complex with the p53K370me2 and p53K382me2 peptides show a remarkable plasticity of 53BP1 in accommodating these diverse dimethyllysine-containing sequences. We demonstrate that dimeric TTDs are capable of interacting with the two PTMs on a single p53K370me2K382me2 peptide, greatly strengthening the 53BP1-p53 interaction. Analysis of binding affinities of TTD toward methylated p53 and histones reveals strong preference of 53BP1 for p53K382me2, H4K20me2, and H3K36me2 and suggests a possible role of multivalent contacts of 53BP1 in p53 targeting to and accumulation at the sites of DNA damage. PMID:25579814

  5. Global Analysis of the Membrane Subproteome of Pseudomonas aeruginosa using Liquid Chromatography-Tandem Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Blonder, Josip; Goshe, Michael B.; Xiao, Wenzhong; Camp, David G.; Wingerd, Mark A.; Davis, Ronald W.; Smith, Richard D.

    2004-05-30

    Pseudomonas aeruginosa is one of the most significant opportunistic bacterial pathogens in humans causing infections and premature death in patients with cystic fibrosis, AIDS, severe burns, organ transplants or cancer. Liquid chromatography coupled online with tandem mass spectrometry (LC-MS/MS) was used for the large-scale proteomic analysis of the P. aeruginosa membrane subproteome. Concomitantly, an affinity labeling technique, using iodoacetyl-PEO biotin to tag cysteinyl-containing proteins, permitted the enrichment and detection of lower abundance membrane proteins. The application of these approaches resulted in the identification of 786 proteins. A total of 333 proteins (42%) had a minimum of one transmembrane domain (TMD; ranging from 1 to 14) and 195 proteins were classified as hydrophobic based on their positive GRAVY values (ranging from 0.01 to 1.32). Key integral inner and outer membrane proteins involved in adaptation and antibiotic resistance were conclusively identified, including the detection of 53% of all predicted opr-type porins (outer integral membrane proteins) and all the components of the mexA-mexB-oprM transmembrane protein complex. This work represents the most comprehensive qualitative proteomic analysis of the membrane subproteome of P. aeruginosa and for prokaryotes in general to date.

  6. Additions to the Human Plasma Proteome via a Tandem MARS Depletion iTRAQ-Based Workflow

    Directory of Open Access Journals (Sweden)

    Zhiyun Cao

    2013-01-01

    Full Text Available Robust platforms for determining differentially expressed proteins in biomarker and discovery studies using human plasma are of great interest. While increased depth in proteome coverage is desirable, it is associated with costs of experimental time due to necessary sample fractionation. We evaluated a robust quantitative proteomics workflow for its ability (1 to provide increased depth in plasma proteome coverage and (2 to give statistical insight useful for establishing differentially expressed plasma proteins. The workflow involves dual-stage immunodepletion on a multiple affinity removal system (MARS column, iTRAQ tagging, offline strong-cation exchange chromatography, and liquid chromatography tandem mass spectrometry (LC-MS/MS. Independent workflow experiments were performed in triplicate on four plasma samples tagged with iTRAQ 4-plex reagents. After stringent criteria were applied to database searched results, 689 proteins with at least two spectral counts (SC were identified. Depth in proteome coverage was assessed by comparison to the 2010 Human Plasma Proteome Reference Database in which our studies reveal 399 additional proteins which have not been previously reported. Additionally, we report on the technical variation of this quantitative workflow which ranges from ±11 to 30%.

  7. Additions to the Human Plasma Proteome via a Tandem MARS Depletion iTRAQ-Based Workflow.

    Science.gov (United States)

    Cao, Zhiyun; Yende, Sachin; Kellum, John A; Robinson, Renã A S

    2013-01-01

    Robust platforms for determining differentially expressed proteins in biomarker and discovery studies using human plasma are of great interest. While increased depth in proteome coverage is desirable, it is associated with costs of experimental time due to necessary sample fractionation. We evaluated a robust quantitative proteomics workflow for its ability (1) to provide increased depth in plasma proteome coverage and (2) to give statistical insight useful for establishing differentially expressed plasma proteins. The workflow involves dual-stage immunodepletion on a multiple affinity removal system (MARS) column, iTRAQ tagging, offline strong-cation exchange chromatography, and liquid chromatography tandem mass spectrometry (LC-MS/MS). Independent workflow experiments were performed in triplicate on four plasma samples tagged with iTRAQ 4-plex reagents. After stringent criteria were applied to database searched results, 689 proteins with at least two spectral counts (SC) were identified. Depth in proteome coverage was assessed by comparison to the 2010 Human Plasma Proteome Reference Database in which our studies reveal 399 additional proteins which have not been previously reported. Additionally, we report on the technical variation of this quantitative workflow which ranges from ±11 to 30%.

  8. Measurements of the Ratio of Neutron Capture Cross Section of 71Ga and 180Hf to 197Au From 0.5 to 3.0 MeV

    Institute of Scientific and Technical Information of China (English)

    CHENXiong-jun; CHANGHong-wei; JIANGLi-yang; ZHONGQi-ping; HANXiao-gang; YUWei-xiang; LIJing-wen; LUHan-lin

    2003-01-01

    The measurements of the ratio of neutron capture cross section of 71Ga and 180Hf to 197Au were carried out at 5SDH-2 tandem accelerator and 600 kV Cockroft-Walton accelerator. Neutrons were produced in the energy region from 0.5 MeV to 2.0 MeV by the T(p, n) reaction at 5SDH-2 tandem accelerator, in the energy 3.0 MeV by the D(d, n) reaction at Cockroft-Walton accelerator, respectively.The activation technique was used in this work.

  9. Charged Covalent Triazine Frameworks for CO2 Capture and Conversion.

    Science.gov (United States)

    Buyukcakir, Onur; Je, Sang Hyun; Talapaneni, Siddulu Naidu; Kim, Daeok; Coskun, Ali

    2017-03-01

    The quest for the development of new porous materials addressing both CO2 capture from various sources and its conversion into useful products is a very active research area and also critical in order to develop a more sustainable and environmentally-friendly society. Here, we present the first charged covalent triazine framework (cCTF) prepared by simply heating nitrile functionalized dicationic viologen derivatives under ionothermal reaction conditions using ZnCl2 as both solvent and trimerization catalyst. It has been demonstrated that the surface area, pore volume/size of cCTFs can be simply controlled by varying the synthesis temperature and the ZnCl2 content. Specifically, increasing the reaction temperature led to controlled increase in the mesopore content and facilitated the formation of hierarchical porosity, which is critical to ensure efficient mass transport within porous materials. The resulting cCTFs showed high specific surface areas up to 1247 m(2) g(-1), and high physicochemical stability. The incorporation of ionic functional moieties to porous organic polymers improved substantially their CO2 affinity (up to 133 mg g(-1), at 1 bar and 273 K) and transformed them into hierarchically porous organocatalysts for CO2 conversion. More importantly, the ionic nature of cCTFs, homogeneous charge distribution together with hierarchical porosity offered a perfect platform for the catalytic conversion of CO2 into cyclic carbonates in the presence of epoxides through an atom economy reaction in high yields and exclusive product selectivity. These results clearly demonstrate the promising aspect of incorporation of charged units into the porous organic polymers for the development of highly efficient porous organocatalysts for CO2 capture and fixation.

  10. Impact of automatic threshold capture on pulse generator longevity

    Institute of Scientific and Technical Information of China (English)

    CHEN Ruo-han; CHEN Ke-ping; WANG Fang-zheng; HUA Wei; ZHANG Shu

    2006-01-01

    Background The automatic, threshold tracking, pacing algorithm developed by St. Jude Medical, verifies ventricular capture beat by beat by recognizing the evoked response following each pacemaker stimulus. This function was assumed to be not only energy saving but safe. This study estimated the extension in longevity obtained by AutoCapture (AC) compared with pacemakers programmed to manually optimized, nominal output.Methods Thirty-four patients who received the St. Jude Affinity series pacemaker were included in the study.The following measurements were taken: stimulation and sensing threshold, impedance of leads, evoked response and polarization signals by 3501 programmer during followup, battery current and battery impedance under different conditions. For longevity comparison, ventricular output was programmed under three different conditions: (1) AC on; (2) AC off with nominal output, and (3) AC off with pacing output set at twice the pacing threshold with a minimum of 2.0 V. Patients were divided into two groups: chronic threshold is higher or lower than 1 V. The efficacy of AC was evaluated.Results Current drain in the AC on group, AC off with optimized programming or nominal output was (14.33±2.84) mA, (16.74±2.75) mA and (18.4±2.44) mA, respectively (AC on or AC off with optimized programming vs. nominal output, P < 0.01). Estimated longevity was significantly extended by AC on when compared with nominal setting [(103 ± 27) months, (80 ± 24) months, P < 0.01). Furthermore, compared with the optimized programming, AC extends the longevity when the pacing threshold is higher than 1 V.Conclusion AC could significantly prolong pacemaker longevity; especially in the patient with high pacing threshold.

  11. Status of the LLL tandem-shaped charge designs

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, C.S.; Jandrisevits, R.A.

    1979-02-22

    Lawrence Livermore Laboratory has been engaged in the design of tandem or multistage shaped charges for several years. Analytical and experimental work that focuses on how several aspects of tandem designs affect the jet characteristics is described. The work demonstrates the effectiveness of analytical methodology to specify liner geometries to achieve jets with controlled velocity gradients and high overall efficiency. It also shows that jet clippers and other ancillary components, along with controlled liner thickness, help make clean breaks between the jet and the slug and facilitate insertion of a second jet. Second-stage initiation and interjet time delays are discussed.

  12. Annual Report of HI-13 Tandem Accelerator in 2013

    Institute of Scientific and Technical Information of China (English)

    KAN; Chao-xin; HU; Yue-ming; BAO; Yi-wen; FAN; Hong-sheng

    2013-01-01

    HI-13 tandem accelerator was running well in 2013,some good works were doing well in maintenance and development.This year the machine has been operated 4 000 hours,and provided beam time 3 100 hours for more than 50 experiment users,the terminal voltage range is from 3 MV to 12.3 MV.1 Operation In 2013,HI-13 tandem accelerator provided 16 kinds of ions.The distribution of beam time versus ion is shown in Fig.1.

  13. Analysis of allergens in tubeimu saponin extracts by using rat basophilic leukemia 2H3 cell-based affinity chromatography coupled to liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Zhang, Tao; Han, Shengli; Liu, Qi; Guo, Ying; He, Langchong

    2014-11-01

    An affinity two-dimensional chromatography method was developed for the recognition, separation, and identification of allergic components from tubeimu saponin extracts, a preparation often injected to treat various conditions as indicated by traditional Chinese medicine. Rat basophilic leukemia-2H3 cell membranes were used as the stationary phase of a membrane affinity chromatography column to capture components with affinity for mast cells that could be involved in a degranulation reaction. The retained components were enriched and analyzed by membrane affinity chromatography with liquid chromatography and mass spectrometry via a port switch valve. Suitability and reliability of the method was investigated using appropriate standards, and then, the method was applied to identify components retained from tubeimu saponin extracts. Tubeimoside A was identified in this way as a potential allergen, and degranulation assays confirmed that tubeimoside A induces RBL-2H3 cell degranulation in a dose-dependent manner. An increase in Ca(2+) influx indicated that degranulation induced by tubeimoside A is likely Ca(2+) dependent. Coupled with the degranulation assay, RBL-2H3 cell-based affinity chromatography coupled with liquid chromatography and mass spectrometry is an effective method for screening and identifying allergic components from tubeimu saponin extracts.

  14. Mass spectrometry insights into a tandem ubiquitin-binding domain hybrid engineered for the selective recognition of unanchored polyubiquitin.

    Science.gov (United States)

    Scott, Daniel; Garner, Tom P; Long, Jed; Strachan, Jo; Mistry, Sharad C; Bottrill, Andrew R; Tooth, David J; Searle, Mark S; Oldham, Neil J; Layfield, Rob

    2016-07-01

    Unanchored polyubiquitin chains are emerging as important regulators of cellular physiology with diverse roles paralleling those of substrate-conjugated polyubiquitin. However tools able to discriminate unanchored polyubiquitin chains of different isopeptide linkages have not been reported. We describe the design of a linker-optimized ubiquitin-binding domain hybrid (t-UBD) containing two UBDs, a ZnF-UBP domain in tandem with a linkage-selective UBA domain, which exploits avidity effects to afford selective recognition of unanchored Lys48-linked polyubiquitin chains. Utilizing native MS to quantitatively probe binding affinities we confirm cooperative binding of the UBDs within the synthetic protein, and desired binding specificity for Lys48-linked ubiquitin dimers. Furthermore, MS/MS analyses indicate that the t-UBD, when applied as an affinity enrichment reagent, can be used to favor the purification of endogenous unanchored Lys48-linked polyubiquitin chains from mammalian cell extracts. Our study indicates that strategies for the rational design and engineering of polyubiquitin chain-selective binding in nonbiological polymers are possible, paving the way for the generation of reagents to probe unanchored polyubiquitin chains of different linkages and more broadly the 'ubiquitome'. All MS data have been deposited in the ProteomeXchange with identifier PXD004059 (http://proteomecentral.proteomexchange.org/dataset/PXD004059).

  15. Capture of irregular satellites at Jupiter

    Energy Technology Data Exchange (ETDEWEB)

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

    2014-03-20

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10{sup –8}. This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  16. Covalent Organic Frameworks for CO2 Capture.

    Science.gov (United States)

    Zeng, Yongfei; Zou, Ruqiang; Zhao, Yanli

    2016-04-20

    As an emerging class of porous crystalline materials, covalent organic frameworks (COFs) are excellent candidates for various applications. In particular, they can serve as ideal platforms for capturing CO2 to mitigate the dilemma caused by the greenhouse effect. Recent research achievements using COFs for CO2 capture are highlighted. A background overview is provided, consisting of a brief statement on the current CO2 issue, a summary of representative materials utilized for CO2 capture, and an introduction to COFs. Research progresses on: i) experimental CO2 capture using different COFs synthesized based on different covalent bond formations, and ii) computational simulation results of such porous materials on CO2 capture are summarized. Based on these experimental and theoretical studies, careful analyses and discussions in terms of the COF stability, low- and high-pressure CO2 uptake, CO2 selectivity, breakthrough performance, and CO2 capture conditions are provided. Finally, a perspective and conclusion section of COFs for CO2 capture is presented. Recent advancements in the field are highlighted and the strategies and principals involved are discussed.

  17. Increased hsp70 of glucocorticoid receptor complex induced by scald and heat stress and its possible effect on the affinity of glucocorticoid receptor

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-hui; TANG Hong-tai; LU Jian; XIA Zhao-fan

    2010-01-01

    Background Glucocorticoid (GC) insensitivity/GC resistance is an important etiological and prognostic factor in multiple diseases and pathophysiological processes such as scald, shock and asthma. The function of GC was mediated by glucocorticoid receptor (GR). Scald not only decreased the expression of GR but also reduced the affinity of GR, which played an important role in GC resistance in scalded rats. Whereas the molecular mechanism responsible for the decrease of GR affinity resulted from scald remains unclear. Recent studies showed that the changes of heat shock proteins (hsp) especially hsp90 and hsp70 of GR heterocomplex were associated with GR low affinity in vitro. Methods The affinity of GR in hepatic cytosols and in the cytosols of SMMC-7721 cells were determined by radioligand binding assay and scatchard plot. GR heterocomplex in cytosols were captured by coimmunoprecipation and the levels of hsp90 and hsp70 of GR complex were detected by quantitative Western blotting.Results Similar with that of hepatic cytosol of scalded rats, a remarkable decrease of GR affinity was also found in the cytosol of heat stressed SMMC-7721 cells. The level of hsp70 of GR complex in hepatic cytosol of scalded rats (30% total body surface area immersion scald) and in cytosol of heat stressed human hepatocarcinoma cell line SMMC-7721 were both increased by 1.5 fold, whereas no change of hsp90 in GR heterocomplex was found. According to the correlation analysis, there may be a positive relationship between increased hsp70 of GR complex and decreased GR affinity in the cytosols.Conclusions The primary results indicated that the level of hsp70 of GR heterocomplex was increased in the hepatic cytosol of scalded rats and the cytosol of heat stressed SMMC-7721 cells. The increase of hsp70 of GR complex might be associated with the decrease of GR affinity.

  18. Neutron capture cross section of Am241

    Science.gov (United States)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for Enwell with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  19. Understanding Motion Capture for Computer Animation

    CERN Document Server

    Menache, Alberto

    2010-01-01

    The power of today's motion capture technology has taken animated characters and special effects to amazing new levels of reality. And with the release of blockbusters like Avatar and Tin-Tin, audiences continually expect more from each new release. To live up to these expectations, film and game makers, particularly technical animators and directors, need to be at the forefront of motion capture technology. In this extensively updated edition of Understanding Motion Capture for Computer Animation and Video Games, an industry insider explains the latest research developments in digital design

  20. Gravitational Capture of Asteroids by Gas Drag

    Directory of Open Access Journals (Sweden)

    E. Vieira Neto

    2009-01-01

    captured by the planet got its velocity reduced and could been trapped as an irregular satellite. It is well known that, depending on the time scale of the gas envelope, an asteroid will spiral and collide with the planet. So, we simulate the passage of the asteroid in the gas envelope with its density decreasing along the time. Using this approach, we found effective captures, and have a better understanding of the whole process. Finally, we conclude that the origin of the irregular satellites cannot be attributed to the gas drag capture mechanism alone.

  1. Design, synthesis, and application of a hydrazide-functionalized isotope-coded affinity tag for the quantification of oxylipid-protein conjugates.

    Science.gov (United States)

    Han, Bingnan; Stevens, Jan F; Maier, Claudia S

    2007-05-01

    An isotopically coded affinity probe was developed and evaluated for the characterization and quantification of proteins adducted by 2-alkenals derived from lipid peroxidation (LPO) processes. Lipid-derived 2-alkenals, such as acrolein and 4-hydroxy-2-nonenal (HNE), have the ability to react with cysteine, histidine, and lysine residues in proteins, thus causing protein damage and loss of protein function. Such modifications of proteins are difficult to characterize in biological samples by mass spectrometry due to the complexity of protein extracts and the low abundance of adducted proteins. The novel aldehyde-reactive, hydrazide-functionalized, isotope-coded affinity tag (HICAT) described in this study was found effective for the selective isolation, detection, and quantification of Michael-type adducts of 2-alkenals with proteins using a combination of affinity isolation, nanoLC, and matrix-assisted laser desorption ionization tandem mass spectrometry (MALDI-MS/MS). The chemical and mass spectrometric properties of the new probe are demonstrated on a model protein treated with HNE. The efficacy of HICAT for the analysis of complex samples was tested using preparations of mitochondrial proteins that were modified in vitro with HNE. The potential of the HICAT strategy for the identification, characterization, and quantification of in vivo oxylipid-protein conjugates is demonstrated on cardiac mitochondrial protein preparations, in which, for example, the ADP/ATP translocase 1 was found adducted to the 2-alkenals, acrolein and 4-hydroxy-2-hexenal, at Cys-256.

  2. BAD-lectins: boronic acid-decorated lectins with enhanced binding affinity for the selective enrichment of glycoproteins.

    Science.gov (United States)

    Lu, Ying-Wei; Chien, Chih-Wei; Lin, Po-Chiao; Huang, Li-De; Chen, Chang-Yang; Wu, Sz-Wei; Han, Chia-Li; Khoo, Kay-Hooi; Lin, Chun-Cheng; Chen, Yu-Ju

    2013-09-03

    The weak and variable binding affinities exhibited by lectin-carbohydrate interactions have often compromised the practical utility of lectin in capturing glycoproteins for glycoproteomic applications. We report here the development and applications of a new type of hybrid biomaterial, namely a boronic acid-decorated lectin (BAD-lectin), for efficient bifunctional glycoprotein labeling and enrichment. Our binding studies showed an enhanced affinity by BAD-lectin, likely to be mediated via the formation of boronate ester linkages between the lectin and glycan subsequent to the initial recognition process and thus preserving its glycan-specificity. Moreover, when attached to magnetic nanoparticles (BAD-lectin@MNPs), 2 to 60-fold improvement on detection sensitivity and enrichment efficiency for specific glycoproteins was observed over the independent use of either lectin or BA. Tested at the level of whole cell lysates for glycoproteomic applications, three different types of BAD-lectin@MNPs exhibited excellent specificities with only 6% overlapping among the 295 N-linked glycopeptides identified. As many as 236 N-linked glycopeptides (80%) were uniquely identified by one of the BAD-lectin@MNPs. These results indicated that the enhanced glycan-selective recognition and binding affinity of BAD-lectin@MNPs will facilitate a complementary identification of the under-explored glycoproteome.

  3. Aptamer-based organic-silica hybrid affinity monolith prepared via "thiol-ene" click reaction for extraction of thrombin.

    Science.gov (United States)

    Wang, Zheng; Zhao, Jin-cheng; Lian, Hong-zhen; Chen, Hong-yuan

    2015-06-01

    A novel strategy for preparing aptamer-based organic-silica hybrid monolithic column was developed via "thiol-ene" click chemistry. Due to the large specific surface area of the hybrid matrix and the simplicity, rapidness and high efficiency of "thiol-ene" click reaction, the average coverage density of aptamer on the organic-silica hybrid monolith reached 420 pmol μL(-1). Human α-thrombin can be captured on the prepared affinity monolithic column with high specificity and eluted by NaClO4 solution. N-p-tosyl-Gly-Pro-Arg p-nitroanilide acetate was used as the sensitive chromogenic substrate of thrombin. The thrombin enriched by this affinity column was detected with a detection of limit of 0.01 μM by spectrophotometry. Furthermore, the extraction recovery of thrombin at 0.15 μM in human serum was 91.8% with a relative standard deviation of 4.0%. These results indicated that "thiol-ene" click chemistry provided a promising technique to immobilize aptamer on organic-inorganic hybrid monolith and the easily-assembled affinity monolithic material could be used to realize highly selective recognition of trace proteins.

  4. Affine kinematics in planar fibrous connective tissues: an experimental investigation.

    Science.gov (United States)

    Jayyosi, C; Affagard, J-S; Ducourthial, G; Bonod-Bidaud, C; Lynch, B; Bancelin, S; Ruggiero, F; Schanne-Klein, M-C; Allain, J-M; Bruyère-Garnier, K; Coret, M

    2017-03-29

    The affine transformation hypothesis is usually adopted in order to link the tissue scale with the fibers scale in structural constitutive models of fibrous tissues. Thanks to the recent advances in imaging techniques, such as multiphoton microscopy, the microstructural behavior and kinematics of fibrous tissues can now be monitored at different stretching within the same sample. Therefore, the validity of the affine hypothesis can be investigated. In this paper, the fiber reorientation predicted by the affine assumption is compared to experimental data obtained during mechanical tests on skin and liver capsule coupled with microstructural imaging using multiphoton microscopy. The values of local strains and the collagen fibers orientation measured at increasing loading levels are used to compute a theoretical estimation of the affine reorientation of collagen fibers. The experimentally measured reorientation of collagen fibers during loading could not be successfully reproduced with this simple affine model. It suggests that other phenomena occur in the stretching process of planar fibrous connective tissues, which should be included in structural constitutive modeling approaches.

  5. Protein purification by aminosquarylium cyanine dye-affinity chromatography.

    Science.gov (United States)

    Silva, M S; Graça, V C; Reis, L V; Santos, P F; Almeida, P; Queiroz, J A; Sousa, F

    2013-12-01

    The most selective purification method for proteins and other biomolecules is affinity chromatography. This method is based on the unique biological-based specificity of the biomolecule-ligand interaction and commonly uses biological ligands. However, these ligands may present some drawbacks, mainly because of their cost and lability. Dye-affinity chromatography overcomes the limitations of biological ligands and is widely used owing to the low cost of synthetic dyes and to their resistance to biological and chemical degradation. In this work, immobilized aminosquarylium cyanine dyes are used in order to exploit affinity interactions with standard proteins such as lysozyme, α-chymotrypsin and trypsin. These studies evaluate the affinity interactions occurring between the immobilized ligand and the different proteins, as a reflection of the sum of several molecular interactions, namely ionic, hydrophobic and van der Waals, spread throughout the structure, in a defined spatial manner. The results show the possibility of using an aminosquarylium cyanine dye bearing a N-hexyl pendant chain, with a ligand density of 1.8 × 10(-2) mmol of dye/g of chromatographic support, to isolate lysozyme, α-chymotrypsin and trypsin from a mixture. The application of a decreasing ammonium sulfate gradient resulted in the recovery of lysozyme in the flowthrough. On the other hand, α-chymotrypsin and trypsin were retained, involving different interactions with the ligand. In conclusion, this study demonstrates the potential applicability of ligands such as aminosquarylium cyanine dyes for the separation and purification of proteins by affinity chromatography.

  6. The proton affinities of saturated and unsaturated heterocyclic molecules

    Science.gov (United States)

    Kabli, Samira; van Beelen, Eric S. E.; Ingemann, Steen; Henriksen, Lars; Hammerum, Steen

    2006-03-01

    The proton affinities derived from G3-calculations of 23 five-membered ring heteroaromatic molecules agree well with the experimentally determined values available in the literature. The calculated local proton affinities show that the principal site of protonation of the heteroaromatic compounds examined is an atom of the ring, carbon when there is only one heteroatom in the ring, and nitrogen where there are two or more heteroatoms. The experimental proton affinities of non-aromatic cyclic ethers, amines and thioethers are also in excellent agreement with the calculated values, with two exceptions (oxetane, N-methylazetidine). The literature proton affinities of the four simple cyclic ethers, oxetane, tetrahydrofuran, tetrahydropyran and oxepane were confirmed by Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, in order to examine the disagreement between the values predicted by extrapolation or additivity for tetrahydrofuran and tetrahydropyran and those determined by experiment and by calculation. The proton affinity differences between the pairs tetrahydropyran/1,4-dioxane, piperidine/morpholine and related compounds show that introduction of an additional oxygen atom in the ring considerably lowers the basicity.

  7. Craniodental affinities of Southeast Asia's "negritos" and the concordance with their genetic affinities.

    Science.gov (United States)

    Bulbeck, David

    2013-01-01

    Genetic research into Southeast Asia's "negritos" has revealed their deep-rooted ancestry, with time depth comparable to that of Southwest Pacific populations. This finding is often interpreted as evidence that negritos, in contrast to other Southeast Asians, can trace much of their ancestry directly back to the early dispersal of Homo sapiens in the order of 70 kya from Africa to Pleistocene New Guinea and Australia. One view on negritos is to lump them and Southwest Pacific peoples into an "Australoid" race whose geographic distribution had included Southeast Asia prior to the Neolithic incursion of "Mongoloid" farmers. Studies into Semang osteology have revealed some hints of Southwest Pacific affinities in cranial shape, dental morphology, and dental metrical "shape." On the other hand, the Andamanese have been shown to resemble Africans in their craniometrics and South Asians in their dental morphology, while Philippine negritos resemble Mongoloid Southeast Asians in these respects and also in their dental metrics. This study expands the scope of negrito cranial comparisons by including Melayu Malays and additional coverage of South Asians. It highlights the distinction between the Mongoloid-like Philippine negritos and the Andamanese and Semang (and Senoi of Malaya) with their non-Mongoloid associations. It proposes that the early/mid-Holocene dispersal of the B4a1a mitochondrial DNA clade across Borneo, the Philippines, and Taiwan may be important for understanding the distinction between Philippine and other negritos.

  8. PHOENIX: a scoring function for affinity prediction derived using high-resolution crystal structures and calorimetry measurements.

    Science.gov (United States)

    Tang, Yat T; Marshall, Garland R

    2011-02-28

    Binding affinity prediction is one of the most critical components to computer-aided structure-based drug design. Despite advances in first-principle methods for predicting binding affinity, empirical scoring functions that are fast and only relatively accurate are still widely used in structure-based drug design. With the increasing availability of X-ray crystallographic structures in the Protein Data Bank and continuing application of biophysical methods such as isothermal titration calorimetry to measure thermodynamic parameters contributing to binding free energy, sufficient experimental data exists that scoring functions can now be derived by separating enthalpic (ΔH) and entropic (TΔS) contributions to binding free energy (ΔG). PHOENIX, a scoring function to predict binding affinities of protein-ligand complexes, utilizes the increasing availability of experimental data to improve binding affinity predictions by the following: model training and testing using high-resolution crystallographic data to minimize structural noise, independent models of enthalpic and entropic contributions fitted to thermodynamic parameters assumed to be thermodynamically biased to calculate binding free energy, use of shape and volume descriptors to better capture entropic contributions. A set of 42 descriptors and 112 protein-ligand complexes were used to derive functions using partial least-squares for change of enthalpy (ΔH) and change of entropy (TΔS) to calculate change of binding free energy (ΔG), resulting in a predictive r2 (r(pred)2) of 0.55 and a standard error (SE) of 1.34 kcal/mol. External validation using the 2009 version of the PDBbind "refined set" (n = 1612) resulted in a Pearson correlation coefficient (R(p)) of 0.575 and a mean error (ME) of 1.41 pK(d). Enthalpy and entropy predictions were of limited accuracy individually. However, their difference resulted in a relatively accurate binding free energy. While the development of an accurate and applicable

  9. Taking advantage: high-affinity B cells in the germinal center have lower death rates, but similar rates of division, compared to low-affinity cells.

    Science.gov (United States)

    Anderson, Shannon M; Khalil, Ashraf; Uduman, Mohamed; Hershberg, Uri; Louzoun, Yoram; Haberman, Ann M; Kleinstein, Steven H; Shlomchik, Mark J

    2009-12-01

    B lymphocytes producing high-affinity Abs are critical for protection from extracellular pathogens, such as bacteria and parasites. The process by which high-affinity B cells are selected during the immune response has never been elucidated. Although it has been shown that high-affinity cells directly outcompete low-affinity cells in the germinal center (GC), whether there are also intrinsic differences between these cells has not been addressed. It could be that higher affinity cells proliferate more rapidly or are more likely to enter cell cycle, thereby outgrowing lower affinity cells. Alternatively, higher affinity cells could be relatively more resistant to cell death in the GC. By comparing high- and low-affinity B cells for the same Ag, we show here that low-affinity cells have an intrinsically higher death rate than do cells of higher affinity, even in the absence of competition. This suggests that selection in the GC reaction is due at least in part to the control of survival of higher affinity B cells and not by a proliferative advantage conferred upon these cells compared with lower affinity B cells. Control over survival rather than proliferation of low- and high-affinity B cells in the GC allows greater diversity not only in the primary response but also in the memory response.

  10. Reactive Capture of Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I SBIR, Reactive Innovations, LLC (RIL) proposes to develop a compact and lightweight electrochemical to capture carbon dioxide in the martian...

  11. Carbon Dioxide Capture Adsorbents: Chemistry and Methods.

    Science.gov (United States)

    Patel, Hasmukh A; Byun, Jeehye; Yavuz, Cafer T

    2016-12-21

    Excess carbon dioxide (CO2 ) emissions and their inevitable consequences continue to stimulate hard debate and awareness in both academic and public spaces, despite the widespread lack of understanding on what really is needed to capture and store the unwanted CO2 . Of the entire carbon capture and storage (CCS) operation, capture is the most costly process, consisting of nearly 70 % of the price tag. In this tutorial review, CO2 capture science and technology based on adsorbents are described and evaluated in the context of chemistry and methods, after briefly introducing the current status of CO2 emissions. An effective sorbent design is suggested, whereby six checkpoints are expected to be met: cost, capacity, selectivity, stability, recyclability, and fast kinetics.

  12. Capture effeciency of a vegetative environmental buffer

    Science.gov (United States)

    Particulate matter emitted from tunnel-ventilated animal feeding operations (AFOs) is known to transport malodorous compounds. As a mitigation strategy, vegetative environmental buffers (VEBs) are often installed surrounding AFOs to capture particulates and induce lofting and dispersion. Currently, ...

  13. Model based adaptive control of a continuous capture process for monoclonal antibodies production.

    Science.gov (United States)

    Steinebach, Fabian; Angarita, Monica; Karst, Daniel J; Müller-Späth, Thomas; Morbidelli, Massimo

    2016-04-29

    A two-column capture process for continuous processing of cell-culture supernatant is presented. Similar to other multicolumn processes, this process uses sequential countercurrent loading of the target compound in order maximize resin utilization and productivity for a given product yield. The process was designed using a novel mechanistic model for affinity capture, which takes both specific adsorption as well as transport through the resin beads into account. Simulations as well as experimental results for the capture of an IgG antibody are discussed. The model was able to predict the process performance in terms of yield, productivity and capacity utilization. Compared to continuous capture with two columns operated batch wise in parallel, a 2.5-fold higher capacity utilization was obtained for the same productivity and yield. This results in an equal improvement in product concentration and reduction of buffer consumption. The developed model was used not only for the process design and optimization but also for its online control. In particular, the unit operating conditions are changed in order to maintain high product yield while optimizing the process performance in terms of capacity utilization and buffer consumption also in the presence of changing upstream conditions and resin aging.

  14. DC-SIGN plays a stronger role than DCIR in mediating HIV-1 capture and transfer.

    Science.gov (United States)

    Jin, Wei; Li, Chang; Du, Tao; Hu, Kai; Huang, Xin; Hu, Qinxue

    2014-06-01

    The C-type lectin receptors (CLRs) expressed on dendritic cells (DCs), in particular DC-SIGN and DCIR, likely play an important role in HIV-1 early infection. Here, we systematically compared the capture and transfer capability of DC-SIGN and DCIR using a wide range of HIV-1 isolates. Our results indicated that DC-SIGN plays a stronger role than DCIR in DC-mediated HIV-1 capture and transfer. This was further strengthened by the data from transient and stable transfectants, showing that DC-SIGN had better capability, compared with DCIR in HIV-1 capture and transfer. Following constructing and analyzing a series of soluble DC-SIGN and DCIR truncates and chimeras, we demonstrated that the neck domain, but not the CRD, renders DC-SIGN higher binding affinity to gp120 likely via the formation of tetramerization. Our findings provide insights into CLR-mediated HIV-1 capture and transfer, highlighting potential targets for intervention strategies against gp120-CLR interactions.

  15. Enhancing Community Detection By Affinity-based Edge Weighting Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    Community detection refers to an important graph analytics problem of finding a set of densely-connected subgraphs in a graph and has gained a great deal of interest recently. The performance of current community detection algorithms is limited by an inherent constraint of unweighted graphs that offer very little information on their internal community structures. In this paper, we propose a new scheme to address this issue that weights the edges in a given graph based on recently proposed vertex affinity. The vertex affinity quantifies the proximity between two vertices in terms of their clustering strength, and therefore, it is ideal for graph analytics applications such as community detection. We also demonstrate that the affinity-based edge weighting scheme can improve the performance of community detection algorithms significantly.

  16. k-Schur functions and affine Schubert calculus

    CERN Document Server

    Lam, Thomas; Morse, Jennifer; Schilling, Anne; Shimozono, Mark; Zabrocki, Mike

    2014-01-01

    This book gives an introduction to the very active field of combinatorics of affine Schubert calculus, explains the current state of the art, and states the current open problems. Affine Schubert calculus lies at the crossroads of combinatorics, geometry, and representation theory. Its modern development is motivated by two seemingly unrelated directions. One is the introduction of k-Schur functions in the study of Macdonald polynomial positivity, a mostly combinatorial branch of symmetric function theory. The other direction is the study of the Schubert bases of the (co)homology of the affine Grassmannian, an algebro-topological formulation of a problem in enumerative geometry. This is the first introductory text on this subject. It contains many examples in Sage, a free open source general purpose mathematical software system, to entice the reader to investigate the open problems. This book is written for advanced undergraduate and graduate students, as well as researchers, who want to become familiar with ...

  17. REPRESENTATIONS OF AFFINE HECKE ALGEBRAS OF TYPE G2

    Institute of Scientific and Technical Information of China (English)

    Xi Nanhua

    2009-01-01

    Let k be a field and q a nonzero element in k such that the square roots of q are in k.We use Hq to denote an affine Hecke algebra over k of type G2 with parameter q.The purpose of this paper is to study representations of Hq by using based rings of two-sided cells of an affine Weyl group W of type G2.We shall give the classification of irreducible representations of Hq.We also remark that a calculation in [11] actually shows that Theorem 2 in [1] needs a modification, a fact is known to Grojnowski and Tanisaki long time ago.In this paper we also show an interesting relation between Hq and an Hecke algebra corresponding to a certain Coxeter group.Apparently the idea in this paper works for all affine Weyl groups, but that is the theme of another paper.

  18. Fast Affinity Propagation Clustering based on Machine Learning

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar Shrivastava

    2013-01-01

    Full Text Available Affinity propagation (AP was recently introduced as an un-supervised learning algorithm for exemplar based clustering. In this paper a novel Fast Affinity Propagation clustering Approach based on Machine Learning (FAPML has been proposed. FAPML tries to put data points into clusters based on the history of the data points belonging to clusters in early stages. In FAPML we introduce affinity learning constant and dispersion constant which supervise the clustering process. FAPML also enforces the exemplar consistency and one of 'N constraints. Experiments conducted on many data sets such as Olivetti faces, Mushroom, Documents summarization, Thyroid, Yeast, Wine quality Red, Balance etc. show that FAPML is up to 54 % faster than the original AP with better Net Similarity.

  19. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  20. Properties of the Affine Invariant Ensemble Sampler in high dimensions

    CERN Document Server

    Huijser, David; Brewer, Brendon J

    2015-01-01

    We present theoretical and practical properties of the affine-invariant ensemble sampler Markov chain Monte Carlo method. In high dimensions the affine-invariant ensemble sampler shows unusual and undesirable properties. We demonstrate this with an $n$-dimensional correlated Gaussian toy problem with a known mean and covariance structure, and analyse the burn-in period. The burn-in period seems to be short, however upon closer inspection we discover the mean and the variance of the target distribution do not match the expected, known values. This problem becomes greater as $n$ increases. We therefore conclude that the affine-invariant ensemble sampler should be used with caution in high dimensional problems. We also present some theoretical results explaining this behaviour.

  1. Super-Affine Hierarchies and their Poisson Embeddings

    CERN Document Server

    Toppan, F

    1998-01-01

    The link between (super)-affine Lie algebras as Poisson brackets structures and integrable hierarchies provides both a classification and a tool for obtaining superintegrable hierarchies. The lack of a fully systematic procedure for constructing matrix-type Lax operators, which makes the supersymmetric case essentially different from the bosonic counterpart, is overcome via the notion of Poisson embeddings (P.E.), i.e. Poisson mappings relating affine structures to conformal structures (in their simplest version P.E. coincide with the Sugawara construction). A full class of hierarchies can be recovered by using uniquely Lie-algebraic notions. The group-algebraic properties implicit in the super-affine picture allow a systematic derivation of reduced hierarchies by imposing either coset conditions or hamiltonian constraints (or possibly both).

  2. A fast quantum algorithm for the affine Boolean function identification

    Science.gov (United States)

    Younes, Ahmed

    2015-02-01

    Bernstein-Vazirani algorithm (the one-query algorithm) can identify a completely specified linear Boolean function using a single query to the oracle with certainty. The first aim of the paper is to show that if the provided Boolean function is affine, then one more query to the oracle (the two-query algorithm) is required to identify the affinity of the function with certainty. The second aim of the paper is to show that if the provided Boolean function is incompletely defined, then the one-query and the two-query algorithms can be used as bounded-error quantum polynomial algorithms to identify certain classes of incompletely defined linear and affine Boolean functions respectively with probability of success at least 2/3.

  3. Beam optics of the folded tandem ion accelerator at BARC

    Indian Academy of Sciences (India)

    S Santra; P Singh

    2002-07-01

    The beam optics of the 6 MV folded tandem ion accelerator, that has recently been commissioned at Bhabha Atomic Research Centre, Mumbai, is presented. Typical beam trajectories for proton and 12C beams under different conditions, are shown. The constraints on the design due to the use of the infrastructure of the Van de Graaff accelerator, which existed earlier, are discussed.

  4. Tandem, roostes sild ja erinnüsed / Andres Langemets

    Index Scriptorium Estoniae

    Langemets, Andres, 1948-

    2002-01-01

    Arvustus: Tandem. Pegasus on pisut pervers. Tln. : Perioodika, 2002. (Loomingu Raamatukogu ; 1) ; Sild, Ivar. Minu erünnised. Tallinn : LauaPealne, 2002 ; Rooste, Jürgen. Igapäevane Psyhho : kalendaarium et mõista elu / kujund. Mammut. I. k. : Sulemees, 2001

  5. Near-optimal switching strategies for a tandem queue

    NARCIS (Netherlands)

    Leeuwen, D. van; Núñez Queija, R.; Boucherie, R.J.; van Dijk, N.M.

    2015-01-01

    Motivated by various applications in logistics, road traffic and production management, we investigate two versions of a tandem queueing model in which the service rate of the first queue can be controlled. The objective is to keep the mean number of jobs in the second queue as low as possible, with

  6. State-dependent importance sampling for a Jackson tandem network

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2008-01-01

    This paper considers importance sampling as a tool for rare-event simulation. The focus is on estimating the probability of overflow in the downstream queue of a Jacksonian two-node tandem queue – it is known that in this setting ‘traditional’ stateindependent importance-sampling distributions perfo

  7. State-dependent importance sampling for a Jackson tandem network

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2008-01-01

    This paper considers importance sampling as a tool for rare-event simulation. The focus is on estimating the probability of overflow in the downstream queue of a Jacksonian two-node tandem queue – it is known that in this setting ‘traditional’ state-independent importance-sampling distributions perf

  8. State-dependent importance sampling for a Jackson tandem network

    NARCIS (Netherlands)

    Miretskiy, Denis; Scheinhardt, Werner; Mandjes, Michel

    2010-01-01

    This article considers importance sampling as a tool for rare-event simulation. The focus is on estimating the probability of overflow in the downstream queue of a Jacksonian two-node tandem queue; it is known that in this setting “traditional” state-independent importance-sampling distributions per

  9. State-dependent importance sampling for a Jackson tandem network

    NARCIS (Netherlands)

    D. Miretskiy; W. Scheinhardt; M. Mandjes

    2010-01-01

    This article considers importance sampling as a tool for rare-event simulation. The focus is on estimating the probability of overflow in the downstream queue of a Jacksonian two-node tandem queue; it is known that in this setting "traditional" state-independent importance-sampling distributions per

  10. Tandem chemiluminescence-flow injection analysis for dimethoate determination.

    OpenAIRE

    Catalá Icardo, Mónica; López Paz, José Luis; CHOVES BARÓN, CRISTINA

    2010-01-01

    Ministry of Education and Science [CTM2006-11991] FEDER funds Catalá Icardo, M.; López Paz, JL.; Choves Barón, C. (2010). Tandem chemiluminescence-flow injection analysis for dimethoate determination. Luminescence. 25:235-236. doi:10.1002/bio.1217. Senia 235 236 25

  11. Design considerations for the Tandem Junction Solar Cell

    Science.gov (United States)

    Matzen, W. T.; Carbajal, B. G.; Hardy, R. W.

    1979-01-01

    Structure and operation of the tandem junction cell (TJC) are described. The impact of using only back contacts is discussed. A model is presented which explains operation of the TJC in terms of transistor action. The model is applied to predict TJC performance as a function of physical parameters.

  12. II-IV-V Based Thin Film Tandem Photovoltaic Cell

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Nathan [Arizona State Univ., Mesa, AZ (United States); van Schilfgaarde, Mark [Arizona State Univ., Mesa, AZ (United States)

    2012-10-04

    [Through a combination of theory and experiment that, absent unknown mitigating factors, a tandem cell whose (wide-gap. 1.8 eV) top layer is made of ZnSnP2 and whose (narrow gap, 1.1 eV) bottom layer consisting of ZnGeAs2 are near-ideal materials for a tandem cell. Not only are there gaps optimally adjusted to the solar spectrum, but the two compounds are lattice-matched, and their energy band structure and optical absorption are also near-ideal (they closely resemble that of GaAs). Our first major challenge is to establish that high-quality II-IV-V thin films can be synthesized. We have begun growing and characterizing films of ZnGeAs2 and ZnSnP2, initially grown on Ge substrates (the lattice constant of Ge matches these compounds) by pulsed laser ablation and sputtering. In tandem are theoretical calculations to guide the experiments. The goal is to develop methods that can be used to produce a pair of lattice-matched thin films that will be useful in tandem cells.

  13. Ultimate performance of polymer: Fullerene bulk heterojunction tandem solar cells

    NARCIS (Netherlands)

    Kotlarski, J.D.; Blom, P.W.M.

    2011-01-01

    We present the model calculations to explore the potential of polymer:fullerene tandem solar cells. As an approach we use a combined optical and electrical device model, where the absorption profiles are used as starting point for the numerical current-voltage calculations. With this model a maximum

  14. Crux: rapid open source protein tandem mass spectrometry analysis.

    Science.gov (United States)

    McIlwain, Sean; Tamura, Kaipo; Kertesz-Farkas, Attila; Grant, Charles E; Diament, Benjamin; Frewen, Barbara; Howbert, J Jeffry; Hoopmann, Michael R; Käll, Lukas; Eng, Jimmy K; MacCoss, Michael J; Noble, William Stafford

    2014-10-03

    Efficiently and accurately analyzing big protein tandem mass spectrometry data sets requires robust software that incorporates state-of-the-art computational, machine learning, and statistical methods. The Crux mass spectrometry analysis software toolkit ( http://cruxtoolkit.sourceforge.net ) is an open source project that aims to provide users with a cross-platform suite of analysis tools for interpreting protein mass spectrometry data.

  15. Interim report on the tandem mirror hybrid design study

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W. (ed.)

    1979-08-01

    The initial phase of a 2-year design study of a tandem mirror fusion reactor is presented. The following chapters are included: (1) mechanical design of the plant; (2) plasma physics; (3) blanket design; (4) magnet design; (5) injector design; (6) direct convertor design; (7) balance of plant design; (8) fission burner reactor; (9) environment and safety; and (10) economic analysis. (MOW)

  16. Bio-olefins from unsaturated fatty acids via tandem catalysis

    Science.gov (United States)

    A new catalytic route to bio-olefins from unsaturated fatty acids will be described. At the heart of the process, the catalyst apparently functions in a tandem mode by both dynamically isomerizing the positions of double bonds in an aliphatic chain and, subsequently, decarboxylating specific isomers...

  17. 14 CFR 105.45 - Use of tandem parachute systems.

    Science.gov (United States)

    2010-01-01

    ...) Has completed a minimum of 500 freefall parachute jumps using a ram-air parachute, and (iii) Holds a... parachute jump with a tandem parachute system unless— (1) The main parachute has been packed by a certificated parachute rigger, the parachutist in command making the next jump with that parachute, or a...

  18. Data capture and processing. [for Space Station

    Science.gov (United States)

    Lyon, John; Smith, Gene; Carper, Richard

    1987-01-01

    A systems concept developed in response to the specific requirements imposed by the Space Station and affiliated instrumentation is described. Particular attention is given to those subsystems associated with initial data capture, handling, routing, and distribution control for return link data via the Tracking and Data Relay Satellite System. The conceived approach, designated the Customer Data and Operations System, includes a data interface facility and a data handling center whose functions are data capture, demultiplexing and routing, early preprocessing, and ancillary data handling.

  19. Neuroprotective effects of high affinity Σ1 receptor selective compounds.

    Science.gov (United States)

    Luedtke, Robert R; Perez, Evelyn; Yang, Shao-Hua; Liu, Ran; Vangveravong, Suwanna; Tu, Zhude; Mach, Robert H; Simpkins, James W

    2012-03-02

    We previously reported that the antipsychotic drug haloperidol, a multifunctional D2-like dopamine and sigma receptor subtype antagonist, has neuroprotective properties. In this study we further examined the association between neuroprotection and receptor antagonism by evaluating a panel of novel compounds with varying affinity at sigma and D2-like dopamine receptors. These compounds were evaluated using an in vitro cytotoxicity assay that utilizes a hippocampal-derived cell line, HT-22, in the presence or absence of varying concentrations (5 to 20 mM) of glutamate. While haloperidol was found to be a potent neuroprotective agent in this in vitro cell assay, the prototypic sigma 1 receptor agonist (+)-pentazocine was found not to be neuroprotective. Subsequently, the potency for the neuroprotection of HT-22 cells was evaluated for a) three SV series indoles which have nMolar affinity at D2-like receptors but varying affinity at sigma 1 receptor and b) two benzyl phenylacetamides sigma 1 receptor selective compounds which bind with low affinity at D2-like receptors but have nMolar affinity for the sigma 1 receptor. We observed that cytoprotection correlated with the affinity of the compounds for sigma 1 receptors. Based upon results from the HT-22 cell-based in vitro assay, two phenylacetamides, LS-127 and LS-137, were further evaluated in vivo using a transient middle cerebral artery occlusion (t-MCAO) model of stroke. At a dose of 100 μg/kg, both LS-127 and LS-137 attenuated infarct volume by approximately 50%. These studies provide further evidence that sigma 1 receptor selective compounds can provide neuroprotection in cytotoxic situations. These results also demonstrate that sigma 1 receptor selective benzyl phenylacetamides are candidate pharmacotherapeutic agents that could be used to minimize neuronal death after a stroke or head trauma.

  20. Astrophysical S factor for {alpha}-capture on {sup 115}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Filipescu, D.; Cata-Danil, I.; Ivascu, M.; Bucurescu, D.; Zamfir, N.V.; Glodariu, T.; Stroe, L.; Mihai, C.; Marginean, N.; Ghita, D.G.; Marginean, R.; Suliman, G.; Sava, T.; Pascu, S. [Horia-Hulubei National Institute for Physics and Nuclear Engineering, Magurele-Ilfov (Romania); Cata-Danil, G. [Physics Department, University Politehnica, Bucharest (Romania)

    2009-07-01

    The s and r processes calculations can only account for 50% of the {sup 115}Sn abundance, and recent p process calculations cannot explain the remaining fraction. For this reason, the experimental measurement of the S factor of {alpha} capture on {sup 115}Sn is of high importance in explaining the origin of {sup 115}Sn. The cross section of {sup 115}Sn({alpha}, {gamma}){sup 119}Te reaction has been measured in the effective center of mass energy from 9.5 to 14.7 MeV. Enriched self-supporting {sup 115}Sn (56%) foils were bombarded with {alpha} beam delivered by the Bucharest IFIN-HH Tandem Accelerator. The induced activity of {sup 119}Te was measured with two large volume GeHP detectors in close geometry to maximize the detector efficiency. The experimental cross section and astrophysical S factor are compared with statistical model predictions for different global {alpha}-nucleus optical potential.