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Sample records for p1 dp0 diffusion

  1. Angularly Adaptive P1 - Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems

    SciTech Connect

    Brantley, P S

    2006-08-08

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.

  2. Angularly Adaptive P1-Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems

    SciTech Connect

    Brantley, P S

    2005-12-13

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.

  3. Angularly Adaptive P1--Double P0 Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems in Planar Geometry

    SciTech Connect

    Brantley, P S

    2005-06-06

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. The standard P{sub 1} angular approximation represents the angular dependence of the radiation specific intensity using a linear function in the angular domain -1 {le} {mu} {le} 1. In contrast, the DP{sub 0} angular approximation represents the angular dependence as isotropic in each half angular range -1 {le} {mu} < 0 and 0 < {mu} {le} 1. Neglecting the time derivative of the radiation flux, both the P{sub 1} and DP{sub 0} equations can be written as a single diffusion equation for the radiation energy density. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near the non-equilibrium wave front. We develop an adaptive angular technique that locally uses either the DP{sub 0} or the P{sub 1} diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for a test problem due to Su and Olson for which a semi-analytic transport solution exists. The numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation for non-equilibrium grey radiative transfer.

  4. Diffusion Cross Sections for Potassium 4(2)P(3/2) and 4(2)P(1/2) Levels in Rare Gases and Anomalous Light - Drift of Potassium in Neon + Rare Gas Mixtures.

    NASA Astrophysics Data System (ADS)

    Yahyaei-Moayyed, Frazaneh

    We have used a light-induced drift (LID) experiment to determine ratios of cross sections for diffusion of potassium in the excited rm4^2P_ {3/2}, 4^2P_{1/2} and the ground rm4^2S_ {1/2} levels in five rare gases, He, Ne, Ar, Kr, and Xe. The measured ratios are combined with the ground state cross sections and statistically averaged excited cross sections, available from a previously reported light-induced diffusive pulling experiment, to obtain the absolute cross sections for individual fine structure levels. We also report calculated cross-sections based on available potential curves and a coupled-channel theory. Rough qualitative agreement is generally found between the absolute cross sections inferred from experiment and the theoretical values. The light-induced drift experiments, however, measure ratios of cross section differences that are highly sensitive to the potential curves. It is found that the available theoretical potential curves are not adequate for predicting these measured ratios. A new method, using light-induced drift experiment, to measure the ground state diffusion coefficient of potassium vapor in Ar as a buffer gas is also studied and the results are compared to the previous results from the light-induced diffusive pulling experiment. Finally, we report anomalous light-induced drift of potassium vapor in mixtures of Ne with another rare gas (He, Ar, Kr, or Xe). This is the first observation of anomalous light-induced drift in an atomic system. The drift velocity versus laser frequency curve shows a strong deviation from the dispersion curve predicted by the standard theory of light-induced drift based on velocity-independent collision rates. The observed drift velocity versus frequency curves have three zero-crossings. For qualitatively relating the results to the collisional interaction, a strong collision model with different velocity-dependent collision rates is used. The partial pressures that cancel normal light -induced drift also

  5. Genome of Bacteriophage P1

    PubMed Central

    Łobocka, Małgorzata B.; Rose, Debra J.; Plunkett, Guy; Rusin, Marek; Samojedny, Arkadiusz; Lehnherr, Hansjörg; Yarmolinsky, Michael B.; Blattner, Frederick R.

    2004-01-01

    P1 is a bacteriophage of Escherichia coli and other enteric bacteria. It lysogenizes its hosts as a circular, low-copy-number plasmid. We have determined the complete nucleotide sequences of two strains of a P1 thermoinducible mutant, P1 c1-100. The P1 genome (93,601 bp) contains at least 117 genes, of which almost two-thirds had not been sequenced previously and 49 have no homologs in other organisms. Protein-coding genes occupy 92% of the genome and are organized in 45 operons, of which four are decisive for the choice between lysis and lysogeny. Four others ensure plasmid maintenance. The majority of the remaining 37 operons are involved in lytic development. Seventeen operons are transcribed from σ70 promoters directly controlled by the master phage repressor C1. Late operons are transcribed from promoters recognized by the E. coli RNA polymerase holoenzyme in the presence of the Lpa protein, the product of a C1-controlled P1 gene. Three species of P1-encoded tRNAs provide differential controls of translation, and a P1-encoded DNA methyltransferase with putative bifunctionality influences transcription, replication, and DNA packaging. The genome is particularly rich in Chi recombinogenic sites. The base content and distribution in P1 DNA indicate that replication of P1 from its plasmid origin had more impact on the base compositional asymmetries of the P1 genome than replication from the lytic origin of replication. PMID:15489417

  6. One-pot carbanionic synthesis of P1,P2-diglycosyl, P1,P1,P2-triglycosyl, and P1,P1,P2,P2-tetraribosyl methylenediphosphonates.

    PubMed

    Grison, Claude; Chibli, Hicham; Barthès, Nicolas; Coutrot, Philippe

    2006-10-13

    Novel lithiated carbanions derived from ethyl glycosyl- and diglycosyl methylphosphonates were used in a direct and convenient synthesis of P1,P2-diglycosyl, P1,P1,P2-triglycosyl, and P1,P1,P2,P2-tetraribosyl methylenediphosphonates involving a one-pot methylidenediphosphonylation of sugars.

  7. Morphological Variants of Coliphage P1 1

    PubMed Central

    Walker, Donald H.; Anderson, Thomas F.

    1970-01-01

    Lysates of P1 from all hosts tested contained at least three morphological variants with respect to head size. These were termed “big” (P1B), “small” (P1S), and “minute” (P1M). Since successive clonings of plaques isolated on many different hosts failed to change the proportions of the variants, we concluded that the production of variants was a function of the P1 genome rather than that of the host. In the electron microscope, the heads appeared to be icosadeltahedra, having face-to-face head diameters of 86 ± 2 nm, 65 ± 2 nm, and 47 ± 2 nm. Assuming the head capsids to be composed of the same protein subunits, these diameters were compatible with T = 16, 9, and 4 with a lattice constant (intercapsomere distance) of 12 to 13 nm. The tails of all variants were morphologically indistinguishable. Each consisted of a hollow tail tube surrounded by a contractile sheath attached to the head by means of a “head-neck connector” which could be a specialized vertex capsomere. In CsCl gradients, a number of bands were observed. One band contained the majority of P1B particles and 99% of the plaque-forming units. Two other bands contained P1S particles whose densities suggested a content of about 40 and 60% of the complete P1B genome. The less dense of these two bands also contained defective P1B particles with a calculated content of only 60% of the complete genome. The P1S particles tested injected their deoxyribonucleic acid (DNA) into host cells and killed them. Genetic markers contained in this band could be rescued by infectious P1B particles, confirming the evidence of Ikeda and Tomizawa that this fraction contains P1 DNA. Images PMID:4193834

  8. Detection of inhaled Der p 1.

    PubMed

    Poulos, L M; O'Meara, T J; Sporik, R; Tovey, E R

    1999-09-01

    Measurement of personal exposure to Der p 1 aeroallergen has previously been limited by the low quantity of material collected by sampling systems and the assay sensitivity. This has meant that exposure could only be detected if long sampling periods were used or reservoir dust was artificially disturbed. We have developed a sampling method to sample true personal exposure and combined it with a novel method which is sensitive enough to measure allergen exposure over shorter time frames. To describe normal domestic exposure to dust mite allergen during a range of activities in houses in Sydney, Australia. Inhaled particles containing mite allergen Der p 1 were collected using a nasal air sampler which impacts particles (> approximately 5 microm) onto a protein-binding membrane coated with a thin, porous, adhesive film. The allergen is bound to the membrane in the immediate vicinity of the particle and detected by immunostaining with monoclonal antibodies specific for Der p 1. In addition, samples were collected using a standard Institute of Occupational Medicine (IOM) personal air sampler and the amount of eluted Der p 1 was assayed by ELISA. The median number (range) of inhaled particles containing Der p 1 collected in each 10-min sampling period was: dust raising 5 (2-10); lying in bed, 0 (0-2); sitting on the bed, 1 (0-2); walking around the bedroom, 0 (0-2). This represented 0-5.1% of all particles captured. The Der p 1 concentration of floor and bed dust was 19.4 and 55.1 microg/g, respectively. The standard IOM personal sampler and ELISA were unable to detect Der p 1 for any of the activities performed. We were able to count individual allergen-carrying particles inhaled over short time periods, during different domestic exposure situations. This will offer new insight into several aspects of personal allergen exposure.

  9. P-1 truss arrival at KSC

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, is moved from the Shuttle Landing Facility toward the newly constructed RLV hangar (viewed here from inside the hangar) as precaution against bad weather approaching the Center (background). The truss will eventually be transferred to the Operations and Checkout Building for processing. In the background is the Super Guppy transport that brought it to KSC. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P- 1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  10. P-1 truss arrival at KSC

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers oversee the placement of the P-1 truss, a component of the International Space Station, onto a flatbed truck that will move it to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P- 1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  11. P-1 truss arrival at KSC

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, arrives inside the RLV hangar, located near the Shuttle Landing Facility at KSC. Approaching bad weather caused the detour as a precaution. The truss will eventually be transferred to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by- 15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  12. Expression of human protamine P1 in sperm of transgenic mice

    SciTech Connect

    Wyrobek, A.J.; Keith, C.; Stilwell, J.; Lowe, X.; Anderson, G.

    1994-12-31

    Transgenic mice were produced by pronuclear injection with DNA constructs containing human protamine P1 cDNA recombined with a murine protamine P1 promoter, and were identified by PCR. Expression of human P1 was investigated using huplm, a monoclonal antibody specific for human P1, applied to murine testicular cells, smears of epididymal sperm, and smears of detergent-isolated sperm nuclei. Various antibodies and nontransgenic littermates were used as controls. Two male founders (T3 and T7) sired more than five generations of transgenic offspring each with continued expression of human P1 in their sperm. Transgenic animals appear of normal fertility with sperm of typical nuclear morphology. The human P1 transgene was expressed postmeioticly in both lines, as expected. Nearly 100% of sperm of T3 and T7 hemizygotes labeled with huplm, consistent with complete diffusion of human P1 protein through the intercellular bridge of spermatogenic cells. Human P1 labeling of sperm nuclei was not visibly affected by sonication or by treatment with the detergent MATAB or the reducing agent DTT. A third founder female (T5) showed a transmission pattern consistent with insertion of the transgene into an X chromosome; her transgenic offspring expressed human P1 in only a small fraction of sperm. Human P1 transgenes may serve as efficient targets for germinal mutations and transgenicmice may provide promising models for investigating the DNA complexes.

  13. Radiative transport in the delta-P1 approximation for semi-infinite turbid media

    PubMed Central

    Seo, InSeok; Hayakawa, Carole K.; Venugopalan, Vasan

    2012-01-01

    We have developed an analytic solution for spatially resolved diffuse reflectance within the δ-P1 approximation to the radiative transport equation for a semi-infinite homogeneous turbid medium. We evaluate the performance of this solution by comparing its predictions with those provided by Monte Carlo simulations and the standard diffusion approximation. We demonstrate that the δ-P1 approximation provides accurate estimates for spatially resolved diffuse reflectance in both low and high scattering media. We also develop a multi-stage nonlinear optimization algorithm in which the radiative transport estimates provided by the δ-P1 approximation are used to recover the optical absorption (μa), reduced scattering ( μs′), and single-scattering asymmetry coefficients (g1) of liquid and solid phantoms from experimental measurements of spatially resolved diffuse reflectance. Specifically, the δ-P1 approximation can be used to recover μa, μs′, and g1 with errors within ±22%, ±18%, and ±17%, respectively, for both intralipid-based and siloxane-based tissue phantoms. These phantoms span the optical property range 4<(μs′/μa)<117. Using these same measurements, application of the standard diffusion approximation resulted in the recovery of μa and μs′ with errors of ±29% and ±25%, respectively. Collectively, these results demonstrate that the δ-P1 approximation provides accurate radiative transport estimates that can be used to determine accurately the optical properties of biological tissues, particularly in spectral regions where tissue may display moderate/low ratios of reduced scattering to absorption ( μs′/μa). PMID:18383690

  14. 26 CFR 31.3402(p)-1 - Voluntary withholding agreements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Voluntary withholding agreements. 31.3402(p)-1 Section 31.3402(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Collection of Income Tax at Source § 31.3402(p)-1 Voluntary withholding agreements. (a) In...

  15. 26 CFR 31.3402(p)-1 - Voluntary withholding agreements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Voluntary withholding agreements. 31.3402(p)-1 Section 31.3402(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Collection of Income Tax at Source § 31.3402(p)-1 Voluntary withholding agreements. (a) In...

  16. 26 CFR 31.3402(p)-1 - Voluntary withholding agreements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Voluntary withholding agreements. 31.3402(p)-1 Section 31.3402(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Collection of Income Tax at Source § 31.3402(p)-1 Voluntary withholding agreements. (a) In...

  17. 26 CFR 31.3402(p)-1 - Voluntary withholding agreements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Voluntary withholding agreements. 31.3402(p)-1 Section 31.3402(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Collection of Income Tax at Source § 31.3402(p)-1 Voluntary withholding agreements. (a) In...

  18. Biochemical and immunological characterization of recombinant allergen Lol p 1.

    PubMed

    Tamborini, E; Faccini, S; Lidholm, J; Svensson, M; Brandazza, A; Longhi, R; Groenlund, H; Sidoli, A; Arosio, P

    1997-11-01

    Pollen from perennial rye grass (Lolium perenne), a major cause of type-I allergy worldwide, contains a complex mixture of allergenic proteins among which Lol p 1 is one of the most important. We describe the expression, purification and characterization of a recombinant Lol p 1 overproduced in Escherichia coli. The recombinant allergen, expressed in high yields and purified in milligram amounts, bound to specific IgE antibodies from human sera, induced histamine release from sensitized human basophils, and elicited rabbit antisera that recognize specifically recombinant Lol p 1 and natural Lol p 1 of pollen extract. Recombinant Lol p 1 was used to develop ImmunoCAP assays for analysis of 150 sera that were Radioallergosorbent test positive to L. perenne pollen. In 130 of them (87%) the assay detected a significant level of IgE antibodies to Lol p 1, reaching on average 37% of the level obtained with a test for IgE to the whole grass pollen extract. To map epitopes on Lol p 1, we produced three deletion mutants [des-(116-240)-Lol p 1, des-(1-88)-Lol p 1 and des-(133-189)-Lol p 1], which were efficiently expressed in bacteria. These all showed a strong reactivity with the specific rabbit IgG antibodies, but lacked most or all the allergenic properties of recombinant Lol p 1. A study of the antigenic structure of Lol p 1 was performed using the three deletion mutants and a set of 17-18-residue overlapping synthetic peptides covering the whole allergen sequence. The results indicate that human IgE and rabbit IgG antibodies bind to distinct regions of Lol p 1, and that at least some important IgE epitopes are mainly conformational. The findings suggest that recombinant allergens constitute useful reagents for further development of serological diagnosis of allergy, and that it should be possible to produce immunogenic fragments of allergenic proteins without allergenic properties.

  19. Immunological and biological properties of recombinant Lol p 1.

    PubMed

    Boutin, Y; Lamontagne, P; Boulanger, J; Brunet, C; Hébert, J

    1997-03-01

    Current forms of allergy diagnosis and therapies are based on the use of natural allergenic extracts. Despite strong evidence that higher therapeutic efficacy may be achieved with purified allergens, the purification of multiple allergic components from extracts is a fastidious and sometimes an impossible task. However, the use of recombinant allergens may be an alternative to overcome this problem. In this study, we compared the immunological properties of recombinant (r) Lol p 1 with those of the natural protein. We cloned directly the gene encoding Lol p 1 from genomic DNA of ryegrass pollen. This gene was subcloned into the expression vector pMAL-c and expressed as fusion protein. Subsequently, rLol p 1 was cleaved from maltose-binding protein using factor Xa. Using binding inhibition and proliferative assays, we assessed the immunological properties of the recombinant allergens. The capacity of rLol p 1 to trigger basophil histamine release and to elicit a skin reaction was also assessed and compared to those of its natural counterpart. We found that the Lol p 1 gene has no introns since we amplified this gene directly from genomic DNA. We demonstrated that the binding sites of anti-Lol p 1 monoclonal antibody, specific human IgG and IgE antibody are well conserved on rLol p 1 as no difference in the binding inhibition profile was observed when using either natural or recombinant protein. At the T-cell level, rLol p 1 elicited a T-cell response in mice comparable to that observed with the natural protein. In addition, we demonstrated that the biological characteristics of rLol p 1 were comparable to those of the natural counterpart, in that rLol p 1 elicited a skin wheal reaction and induced basophil histamine release in grass-allergic patients only. The data indicate that natural Lol p 1 and rLol p 1 shared identical immunological and biological properties.

  20. Skin tests and histamine release with P1-depleted Dermatophagoides pteronyssinus body extracts and purified P1.

    PubMed

    van der Zee, J S; van Swieten, P; Jansen, H M; Aalberse, R C

    1988-05-01

    Monoclonal antibodies were raised against P1 and Dp X, two major allergens in Dermatophagoides pteronyssinus extracts. The concentrations of IgE antibodies to P1 and Dp X in sera of mite-sensitive patients were determined in RAST with immunosorbent-bound monoclonal antibodies used for insolubilization of the allergens. The major allergen-specific IgE titers were compared with the total IgE response against D. pteronyssinus. The results of these serologic assays confirmed studies in the literature that P1 and Dp X are major allergens. The contribution of IgE anti-P1 to the total antimite response frequently exceeded 50% and, in general, appeared to be higher than the contribution of IgE anti-Dp X. Twenty percent of the mite-sensitive patients had no detectable IgE to either P1 or Dp X. The contribution of P1 to the biologic activity of D. pteronyssinus body extracts was derived from the effect of P1 depletion on the reactivity in the histamine-release test and skin test. This technique was preferred to the study of purified allergen because biologic activity of the nonabsorbed components is not affected. Immunization of rabbits with affinity-purified P1 yielded monospecific polyclonal antisera. Mite extracts depleted with either monoclonal or polyclonal anti-P1 were applied in the histamine-release test. The skin test was performed with extracts depleted with polyclonal anti-P1. In addition, the activity of affinity-purified P1 was investigated in these tests. The results indicated that P1 depletion of D. pteronyssinus body extracts had no detectable effect on the activity in most patients, namely, at least 70% of the activity was retained in the depleted extract. There was a considerable variation between patients in the sensitivity for purified P1, as compared to the sensitivity for whole D. pteronyssinus extracts. In the histamine-release test, the activity of purified P1 was up to 35% of the activity of the D. pteronyssinus body extract but did not exceed 10% in

  1. Permeabilization of mitochondria and red blood cells by polycationic peptides BTM-P1 and retro-BTM-P1.

    PubMed

    Lemeshko, Victor V

    2011-10-01

    Mitochondrial and plasma membrane permeabilization by polycationic peptides BTM-P1 and retro-BTM-P1 were studied. BTM-P1 was more active than its retro-analog. In the sucrose medium, the capacity of BTM-P1 to permeabilize mitochondria was lower than in salt media. In contrast, retro-BTM-P1 showed the lowest activity in the KCl medium. The efficacy of both peptides to permeabilize red blood cells was higher in the sucrose medium and depended on the nature of salt in high ionic strength media. BTM-P1, but not retro-BTM-P1, induced biphasic change in light dispersion of red blood cells with artificially generated high transmembrane potential: the initial phase of fast cell shrinkage preceded the subsequent phase of cell swelling. The shrunken red blood cells demonstrated increased sensitivity to BTM-P1 that might be explained by the cell suicide mechanism via phosphatidylserine exposure at the cell surface. As a working hypothesis, we assume that some peptide topology characteristics, such as the orientation and values of the total and local electrical dipole moments, interacting with the membrane dipole potential, as well as the asymmetric distribution of polar and non-polar side chains are important factors affecting the membrane-permeabilizing activity of polycationic peptides.

  2. The P-1 truss in the O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Part of the P-1 truss is seen as it rests in a workstand in the Operations and Checkout Building. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14- by 15-foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away from the sun to increase their maximum cooling efficiency.

  3. Effects of orally applied Fes p1-displaying L. plantarum WCFS1 on Fes p1 induced allergy in mice.

    PubMed

    Minic, Rajna; Gavrovic-Jankulovic, Marija; Petrusic, Vladimir; Zivkovic, Irena; Eijsink, Vincent G H; Dimitrijevic, Ljiljana; Mathiesen, Geir

    2015-04-10

    Group I grass pollen allergens are major contributors to grass pollen-related seasonal allergic rhinitis, and as such a primary target for allergen specific immunotherapy. In this study the potential therapeutic role of oral application of Lactobacillus plantarum WCFS1, directing cell wall attachment of the recombinant Fes p1 allergen, from Festuca pratensis was tested in a mouse model of Fes p1 allergy. For surface expression of Fes p1 allergen in L. plantarum WCFS1 pSIP system with inducible expression was used. Balb/c mice were sensitized with Fes p1 protein in alum and subsequently received live recombinant L. plantarum orally. Antibody levels (IgE, total IgG, IgG1, IgG2a, and IgA) were determined by ELISA. Differential eosinophil count in peripheral blood was performed. Reduced peripheral blood eosinophilia and increased serum IgG2A levels was detected in both groups which received live L. plantarum orally. Specific serum IgA levels were increased only in mice treated with the recombinant bacteria. Oral application of L. plantarum WCFS1 has a beneficial therapeutic effect in a mouse model of Fes p1 allergy. Cell surface expression of Fes p1 allergen potentiates this phenomenon in an allergen specific way.

  4. P-1 truss moved to O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers oversee the placement of the P-1 truss, a component of the International Space Station, onto the bed of a transport vehicle that will move it to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  5. P-1 truss arrives at O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, arrives in the parking lot outside the Operations and Checkout Building where it will undergo processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Space Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  6. P-1 truss moved to O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Cranes place the P-1 truss, a component of the International Space Station, on a transport vehicle that will move it to the Operations and Checkout Building for processing. The truss had been temporarily stored in the RLV hangar in the background as a precaution against approaching bad weather. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by- 15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  7. Transcriptional Auto-Regulation of RUNX1 P1 Promoter

    PubMed Central

    Martinez, Milka; Hinojosa, Marcela; Trombly, Daniel; Morin, Violeta; Stein, Janet; Stein, Gary; Javed, Amjad; Gutierrez, Soraya E.

    2016-01-01

    RUNX1 a member of the family of runt related transcription factors (RUNX), is essential for hematopoiesis. The expression of RUNX1 gene is controlled by two promoters; the distal P1 promoter and the proximal P2 promoter. Several isoforms of RUNX1 mRNA are generated through the use of both promoters and alternative splicing. These isoforms not only differs in their temporal expression pattern but also exhibit differences in tissue specificity. The RUNX1 isoforms derived from P2 are expressed in a variety of tissues, but expression of P1-derived isoform is restricted to cells of hematopoietic lineage. However, the control of hematopoietic-cell specific expression is poorly understood. Here we report regulation of P1-derived RUNX1 mRNA by RUNX1 protein. In silico analysis of P1 promoter revealed presence of two evolutionary conserved RUNX motifs, 0.6kb upstream of the transcription start site, and three RUNX motifs within 170bp of the 5’UTR. Transcriptional contribution of these RUNX motifs was studied in myeloid and T-cells. RUNX1 genomic fragment containing all sites show very low basal activity in both cell types. Mutation or deletion of RUNX motifs in the UTR enhances basal activity of the RUNX1 promoter. Chromatin immunoprecipitation revealed that RUNX1 protein is recruited to these sites. Overexpression of RUNX1 in non-hematopoietic cells results in a dose dependent activation of the RUNX1 P1 promoter. We also demonstrate that RUNX1 protein regulates transcription of endogenous RUNX1 mRNA in T-cell. Finally we show that SCL transcription factor is recruited to regions containing RUNX motifs in the promoter and the UTR and regulates activity of the RUNX1 P1 promoter in vitro. Thus, multiple lines of evidence show that RUNX1 protein regulates its own gene transcription. PMID:26901859

  8. Transcriptional Auto-Regulation of RUNX1 P1 Promoter.

    PubMed

    Martinez, Milka; Hinojosa, Marcela; Trombly, Daniel; Morin, Violeta; Stein, Janet; Stein, Gary; Javed, Amjad; Gutierrez, Soraya E

    2016-01-01

    RUNX1 a member of the family of runt related transcription factors (RUNX), is essential for hematopoiesis. The expression of RUNX1 gene is controlled by two promoters; the distal P1 promoter and the proximal P2 promoter. Several isoforms of RUNX1 mRNA are generated through the use of both promoters and alternative splicing. These isoforms not only differs in their temporal expression pattern but also exhibit differences in tissue specificity. The RUNX1 isoforms derived from P2 are expressed in a variety of tissues, but expression of P1-derived isoform is restricted to cells of hematopoietic lineage. However, the control of hematopoietic-cell specific expression is poorly understood. Here we report regulation of P1-derived RUNX1 mRNA by RUNX1 protein. In silico analysis of P1 promoter revealed presence of two evolutionary conserved RUNX motifs, 0.6kb upstream of the transcription start site, and three RUNX motifs within 170bp of the 5'UTR. Transcriptional contribution of these RUNX motifs was studied in myeloid and T-cells. RUNX1 genomic fragment containing all sites show very low basal activity in both cell types. Mutation or deletion of RUNX motifs in the UTR enhances basal activity of the RUNX1 promoter. Chromatin immunoprecipitation revealed that RUNX1 protein is recruited to these sites. Overexpression of RUNX1 in non-hematopoietic cells results in a dose dependent activation of the RUNX1 P1 promoter. We also demonstrate that RUNX1 protein regulates transcription of endogenous RUNX1 mRNA in T-cell. Finally we show that SCL transcription factor is recruited to regions containing RUNX motifs in the promoter and the UTR and regulates activity of the RUNX1 P1 promoter in vitro. Thus, multiple lines of evidence show that RUNX1 protein regulates its own gene transcription.

  9. P-1 truss moves into O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, sits inside the Operations and Checkout Building where it will undergo processing. The truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  10. STS-113 P1 Truss paylad in Payload Changeout Room

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - From the Payload Changeout Room on Launch Pad 39A, the P1 truss payload, plus the Crew and Equipment Translation Aid (CETA) cart B, are moved into the payload bay of Space Shuttle Endeavour. Scheduled to launch Nov. 10 on mission STS-113, Endeavour will make the 16th assembly flight to the International Space Station. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. The mission will also deliver the Expedition 6 crew to the Station and return Expedition 5 to Earth.

  11. Antimutagenic effect of resveratrol against Trp-P-1.

    PubMed

    Uenobe, F; Nakamura, S; Miyazawa, M

    1997-02-03

    The methanol extract of Yucca schidigera (YE) showed a suppressive effect on umu gene expression of the SOS response induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in Salmonella typhimurium TA1535/pSK1002. The suppressive effect of YE was also observed for 2-aminoanthracene and activated Trp-P-1, without a significant effect on bacterial growth. The extract exhibited a weak suppressive effect on SOS-induction by N-methyl-N'-nitro-N-nitrosoguanidine, but not by furylfuramide or 4-nitroquinoline-1-oxide. The antimutagenic activity of YE against Trp-P-1 was demonstrated by Ames assay using Salmonella typhimurium TA98. Isolation and purification of the active component of YE was carried out using SiO2 column chromatography, and 275 mg of antimutagenic compound was isolated from 2.5 kg of dried chips of yucca roots and branches. The compound was identified as 3,4',5-trihydroxystilbene (THS). The SOS suppression and antimutagenicity of THS against Trp-P-1 was determined by umu test and Ames test.

  12. STS-113 P1 Truss paylad in Payload Changeout Room

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- A worker in the Payload Changeout Room on Launch Pad 39A watches as the P1 truss payload, plus the Crew and Equipment Translation Aid (CETA) cart B, move into the payload bay of Space Shuttle Endeavour. Scheduled to launch Nov. 10 on mission STS-113, Endeavour will make the 16th assembly flight to the International Space Station. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. The mission will also deliver the Expedition 6 crew to the Station and return Expedition 5 to Earth.

  13. Diffusion MRI

    NASA Astrophysics Data System (ADS)

    Fukuyama, Hidenao

    Recent advances of magnetic resonance imaging have been described, especially stressed on the diffusion sequences. We have recently applied the diffusion sequence to functional brain imaging, and found the appropriate results. In addition to the neurosciences fields, diffusion weighted images have improved the accuracies of clinical diagnosis depending upon magnetic resonance images in stroke as well as inflammations.

  14. RELATIVE PHOTOMETRY OF HAT-P-1b OCCULTATIONS

    SciTech Connect

    Beky, Bence; Holman, Matthew J.; Noyes, Robert W.; Sasselov, Dimitar D.; Gilliland, Ronald L.; Bakos, Gaspar A.; Winn, Joshua N.

    2013-06-01

    We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of two occultations of the transiting exoplanet HAT-P-1b. By measuring the planet to star flux ratio near opposition, we constrain the geometric albedo of the planet, which is strongly linked to its atmospheric temperature gradient. An advantage of HAT-P-1 as a target is its binary companion ADS 16402 A, which provides an excellent photometric reference, simplifying the usual steps in removing instrumental artifacts from HST time-series photometry. We find that without this reference star, we would need to detrend the lightcurve with the time of the exposures as well as the first three powers of HST orbital phase, and this would introduce a strong bias in the results for the albedo. However, with this reference star, we only need to detrend the data with the time of the exposures to achieve the same per-point scatter, therefore we can avoid most of the bias associated with detrending. Our final result is a 2{sigma} upper limit of 0.64 for the geometric albedo of HAT-P-1b between 577 and 947 nm.

  15. Relative Photometry of HAT-P-1b Occultations

    NASA Astrophysics Data System (ADS)

    Béky, Bence; Holman, Matthew J.; Gilliland, Ronald L.; Bakos, Gáspár Á.; Winn, Joshua N.; Noyes, Robert W.; Sasselov, Dimitar D.

    2013-06-01

    We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of two occultations of the transiting exoplanet HAT-P-1b. By measuring the planet to star flux ratio near opposition, we constrain the geometric albedo of the planet, which is strongly linked to its atmospheric temperature gradient. An advantage of HAT-P-1 as a target is its binary companion ADS 16402 A, which provides an excellent photometric reference, simplifying the usual steps in removing instrumental artifacts from HST time-series photometry. We find that without this reference star, we would need to detrend the lightcurve with the time of the exposures as well as the first three powers of HST orbital phase, and this would introduce a strong bias in the results for the albedo. However, with this reference star, we only need to detrend the data with the time of the exposures to achieve the same per-point scatter, therefore we can avoid most of the bias associated with detrending. Our final result is a 2σ upper limit of 0.64 for the geometric albedo of HAT-P-1b between 577 and 947 nm.

  16. Safety evaluation of nuclease P1 from Penicillium citrinum.

    PubMed

    Okado, Nobuo; Hasegawa, Kazushige; Mizuhashi, Fukutaro; Lynch, Barry S; Vo, Trung D; Roberts, Ashley S

    2016-02-01

    Nuclease P1 has been widely used in the food industry to enhance or create flavor. One commercial source of this enzyme is Penicillium citrinum, an anamorphic mesophilic fungus with a long history of safe use in Europe and Asia as a fermentation organism used in the production of ribonucleases. Given the intended use in food for human consumption, and noting its potential presence at trace levels in finished products, a series of safety studies including an in vitro Ames and chromosome aberration assay, an in vivo rat erythrocyte micronucleus assay and a 90-day oral toxicity study in rats were conducted. No mutagenic activity was observed in the Ames assay. Equivocal activity in the chromosome aberration assay was not replicated in the micronucleus assay at doses of up to 1007 mg total organic solids (TOS)/kg body weight (bw)/day. Following oral administration of nuclease P1 at dosages of 10.1, 101 or 1007 mg TOS/kg bw/day to Sprague-Dawley rats, no adverse effects on any study parameter were observed. The no-observed-adverse-effect level was considered to be 1007 mg TOS/kg bw/day. The results of the genotoxicity studies and subchronic rat study support the safe use in food production of nuclease P1 produced from P. citrinum.

  17. Characterization and adsorption of Lactobacillus virulent phage P1.

    PubMed

    Chen, X; Xi, Y; Zhang, H; Wang, Z; Fan, M; Liu, Y; Wu, W

    2016-09-01

    Bacteriophage infection of lactic acid bacteria is considered an important problem worldwide in the food fermentation industry, as it may produce low quality or unsafe foods, cause fermentation failure, and result in economic losses. To increase current knowledge on the properties of Lactobacillus virulent phages, we evaluated the effect of divalent cations, temperature, pH, and chloramphenicol on the adsorption ability of Lactobacillus virulent phage P1. Phage P1 was isolated from the abnormal fermentation liquid of Lactobacillus plantarum IMAU10120. The results showed that this phage belonged to the Siphoviridae family. The latent period of this phage was 45min, and the burst time was 90min. Burst size was 132.88±2.37 phage counts expressed per milliliter per infective center. This phage showed good tolerance at different temperatures, but incubation at 50°C only affected its adsorption. Adsorption rate reached a maximum value between 30 and 42°C. A high adsorption value of phage infectivity was obtained from pH 6 to 8. Moreover, calcium ions promoted and increased the adsorption capacity of phage P1, but magnesium ions had negative effects. Chloramphenicol had no effect on phage adsorption. This study increased current knowledge on the characterization and biological aspects of Lactobacillus virulent phages, and may provide some basic information that can be used to design successful antiphage strategies in the food industry. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. A deterministic version of Pollard's p-1 algorithm

    NASA Astrophysics Data System (ADS)

    Zral/Ek, Bartosz

    2010-01-01

    In this article we present applications of smooth numbers to the unconditional derandomization of some well-known integer factoring algo- rithms. We begin with Pollard's p-1 algorithm, which finds in random polynomial time the prime divisors p of an integer n such that p-1 is smooth. We show that these prime factors can be recovered in deterministic polynomial time. We further generalize this result to give a partial derandomization of the k -th cyclotomic method of factoring ( k≥2 ) devised by Bach and Shallit. We also investigate reductions of factoring to computing Euler's totient function ϕ . We point out some explicit sets of integers n that are completely factorable in deterministic polynomial time given ϕ(n) . These sets consist, roughly speaking, of products of primes p satisfying, with the exception of at most two, certain conditions somewhat weaker than the smoothness of p-1 . Finally, we prove that O(ln n) oracle queries for values of ϕ are sufficient to completely factor any integer n in less than expBigl((1+o(1))(ln n)^{1/3} (lnln n)^{2/3}Bigr) deterministic time.

  19. Plasmapause diffusion

    NASA Technical Reports Server (NTRS)

    Horwitz, J. L.

    1983-01-01

    The Bohm diffusion coefficient and observed electrostatic wave scattering are used as the bases of estimates of the smoothing effect that diffusion may have on steep plasmapause density gradients. The estimate for diffusion resulting from scattering by observed electrostatic waves is found to be much lower than that of the perpendicular Bohm diffusion coefficient for characteristic plasma temperatures and magnetic fields. This diffusion rate estimate may be too small, however, if the wave amplitudes are significantly higher for steep plasmapauses. The effects are therefore negligible for most considerations of macroscopic plasmapause dynamics, but may be significant in limiting drift wave instabilities and similar phenomena driven by the steepness of the plasmapause density gradient.

  20. Modulation of P1 and EGF Expression by Baicalin

    PubMed Central

    Meng, Yanli; Huo, Jinhai; Lu, Weihong; Wang, Xin; Zhang, Junwei; Wang, Weiming

    2013-01-01

    Mycoplasma pneumoniae (M. pneumoniae) is increasingly recognized as a major cause of acute respiratory tract infections. Today, macrolides are used in the primary treatment of M. pneumoniae infection. However, with the increasing prevalence of strains resistant to macrolides, as well as reports of toxicity and adverse side effects, it is necessary to develop an alternative therapeutic agent. A compound recipe—Qinbaiqingfei pellets (Qinbai)—have already been approved in China as the first effective traditional Chinese medicine to be used against M. pneumoniae. Herein, we characterize the mechanism by which Qinbai interacts with M. pneumoniae and lung epithelial cells. The fact that Baicalin is the key component of Qingbai leads us to believe its study is important to elucidating the mechanism of the action of Qinbai. In this study, we describe the complex impact of Baicalin on the adhesin protein P1 of M. pneumoniae and on the expression of epidermal growth factor (EGF) in BALB/c mice and A549 cells infected with M. pneumonia. We draw the conclusion that Baicalin not only cured M. pneumoniae infection by inhibiting P1 expression, but also enhanced the repair of lung epithelial cells by upregulating EGF. Finally, we demonstrate that Baicalin plays a role in Qinbai treatment. PMID:23344025

  1. Integrated P1 Hohlraum/Capsule Simulations for NIF Experiments

    NASA Astrophysics Data System (ADS)

    Eder, David; Spears, Brian; Town, Richard; Jones, Oggie; Ma, Tammy; Pak, Arthur; Benedetti, Robin; Hatchett, Steve; Knauer, James; MacKinnon, Andrew; Yeamans, Charles; McNaney, James; Casey, Daniel

    2014-10-01

    We discuss integrated hohlraum/capsule post-shot simulations of two full-scale cryogenic NIF experiments that drove a DT symcap capsule downward/upward by having the peak power in the upper laser beams 16% greater/less than the lower beams. This laser asymmetry results in a radiation drive P1/P0 at the capsule ablation surface of ~2% and a downward/upward capsule velocity of order 100 microns/ns in agreement with the data. The experimental velocity is determined by comparing measurements at different locations of both the arrival times of DD and DT neutrons at time-of-flight detectors, and by zirconium activation measurements that are a function of neutron energy. We compare these two shots to a control shot for the same target with no specified laser asymmetries. We also discuss simulations of planned sub-scale warm symcap experiments that have a goal of measuring DT and DD ion temperatures and the electron temperature as a function of the imposed P1 to characterize the role of non-thermal velocity on temperature measurements. This work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-656659.

  2. Griffith diffusers

    NASA Technical Reports Server (NTRS)

    Yang, T.-T.; Nelson, C. D.

    1979-01-01

    Contoured wall diffusers are designed by using an inverse method. The prescribed wall velocity distribution(s) was taken from the high lift airfoil designed by A. A. Griffith in 1938; therefore, such diffusers are named Griffith diffusers. First the formulation of the inverse problem and the method of solution are outlined. Then the typical contour of a two-dimensional diffuser and velocity distributions across the flow channel at various stations are presented. For a Griffith diffuser to operate as it is designed, boundary layer suction is necessary. Discussion of the percentage of through-flow required to be removed for the purpose of boundary layer control is given. Finally, reference is made to the latest version of a computer program for a two-dimensional diffuser requiring only area ratio, nondimensional length and suction percentage as inputs.

  3. Griffith diffusers

    NASA Technical Reports Server (NTRS)

    Yang, T.-T.; Nelson, C. D.

    1979-01-01

    Contoured wall diffusers are designed by using an inverse method. The prescribed wall velocity distribution(s) was taken from the high lift airfoil designed by A. A. Griffith in 1938; therefore, such diffusers are named Griffith diffusers. First the formulation of the inverse problem and the method of solution are outlined. Then the typical contour of a two-dimensional diffuser and velocity distributions across the flow channel at various stations are presented. For a Griffith diffuser to operate as it is designed, boundary layer suction is necessary. Discussion of the percentage of through-flow required to be removed for the purpose of boundary layer control is given. Finally, reference is made to the latest version of a computer program for a two-dimensional diffuser requiring only area ratio, nondimensional length and suction percentage as inputs.

  4. The P1 and P1' residue specificities of physarolisin I, a serine-carboxyl peptidase from the true slime mold Physarum polycephalum.

    PubMed

    Nishii, Wataru; Kubota, Keiko; Takahashi, Kenji

    2009-05-01

    The P1 and P1' residue specificities of physarolisin I were investigated using combinatorial peptide substrates. The results indicated that certain hydrophobic residues and acidic residues are preferred at the P1 position and some hydrophobic residues at the P1' position. This P1 specificity, different from other serine-carboxyl peptidases, appears to be explained partially by the nature of the S1 subsite residues.

  5. Plectin isoform P1b and P1d deficiencies differentially affect mitochondrial morphology and function in skeletal muscle.

    PubMed

    Winter, Lilli; Kuznetsov, Andrey V; Grimm, Michael; Zeöld, Anikó; Fischer, Irmgard; Wiche, Gerhard

    2015-08-15

    Plectin, a versatile 500-kDa cytolinker protein, is essential for muscle fiber integrity and function. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Besides displaying pathological desmin-positive protein aggregates and degenerative changes in the myofibrillar apparatus, skeletal muscle specimens of EBS-MD patients and plectin-deficient mice are characterized by massive mitochondrial alterations. In this study, we demonstrate that structural and functional alterations of mitochondria are a primary aftermath of plectin deficiency in muscle, contributing to myofiber degeneration. We found that in skeletal muscle of conditional plectin knockout mice (MCK-Cre/cKO), mitochondrial content was reduced, and mitochondria were aggregated in sarcoplasmic and subsarcolemmal regions and were no longer associated with Z-disks. Additionally, decreased mitochondrial citrate synthase activity, respiratory function and altered adenosine diphosphate kinetics were characteristic of plectin-deficient muscles. To analyze a mechanistic link between plectin deficiency and mitochondrial alterations, we comparatively assessed mitochondrial morphology and function in whole muscle and teased muscle fibers of wild-type, MCK-Cre/cKO and plectin isoform-specific knockout mice that were lacking just one isoform (either P1b or P1d) while expressing all others. Monitoring morphological alterations of mitochondria, an isoform P1b-specific phenotype affecting the mitochondrial fusion-fission machinery and manifesting with upregulated mitochondrial fusion-associated protein mitofusin-2 could be identified. Our results show that the depletion of distinct plectin isoforms affects mitochondrial network organization and function in different ways.

  6. Catalytic activity of nuclease P1: Experiment and theory

    SciTech Connect

    Miller, J.H.; Falcone, J.M.; Shibata, M.; Box, H.C.

    1994-10-01

    Nuclease P1 from Penicillium citrinum is a zinc dependent glyco-enzyme that recognizes single stranded DNA and RNA as substrates and hydrolyzes the phosphate ester bond. Nuclease Pl seems to recognize particular conformations of the phosphodiester backbone and shows significant variation in the rate of hydrolytic activity depending upon which nucleosides are coupled by the phosphodiester bond. The efficiency of nuclease Pl in hydrolyzing the phosphodiester bonds of a substrate can be altered by modifications to one of the substrate bases induced by ionizing radiation or oxidative stress. Measurements have been made of the effect of several radiation induced lesions on the catalytic rate of nuclease Pl. A model of the structure of the enzyme has been constructed in order to better understand the binding and activity of this enzyme on various ssDNA substrates.

  7. Scalable Plasmid Transfer using Engineered P1-based Phagemids

    PubMed Central

    Kittleson, Joshua T.; DeLoache, Will; Cheng, Hsiao-Ying; Anderson, J. Christopher

    2013-01-01

    Dramatic improvements to computational, robotic, and biological tools have enabled genetic engineers to conduct increasingly sophisticated experiments. Further development of biological tools offers a route to bypass complex or expensive mechanical operations, thereby reducing the time and cost of highly parallelized experiments. Here, we engineer a system based on bacteriophage P1 to transfer DNA from one E. coli cell to another, bypassing the need for intermediate DNA isolation (e.g., minipreps). To initiate plasmid transfer, we refactored a native phage element into a DNA module capable of heterologously inducing phage lysis. After incorporating known cis-acting elements, we identified a novel cis-acting element that further improves transduction efficiency, exemplifying the ability of synthetic systems to offer insight into native ones. The system transfers DNAs up to 25 kilobases, the maximum assayed size, and operates well at microliter volumes, enabling manipulation of most routinely used DNAs. The system’s large DNA capacity and physical coupling of phage particles to phagemid DNA suggest applicability to biosynthetic pathway evolution, functional proteomics, and ultimately, diverse molecular biology operations including DNA fabrication. PMID:23656280

  8. Sphingosine 1-Phosphate Receptor 1 (S1P1) Upregulation and Amelioration of Experimental Autoimmune Encephalomyelitis by an S1P1 Antagonist

    PubMed Central

    Cahalan, Stuart M.; Gonzalez-Cabrera, Pedro J.; Nguyen, Nhan; Guerrero, Miguel; Cisar, Elizabeth A. George; Leaf, Nora B.; Brown, Steven J.; Roberts, Edward

    2013-01-01

    Sphingosine 1-phosphate receptor 1 (S1P1) is a G protein–coupled receptor that is critical for proper lymphocyte development and recirculation. Agonists to S1P1 are currently in use clinically for the treatment of multiple sclerosis, and these drugs may act on both S1P1 expressed on lymphocytes and S1P1 expressed within the central nervous system. Agonists to S1P1 and deficiency in S1P1 both cause lymphocyte sequestration in the lymph nodes. In the present study, we show that S1P1 antagonism induces lymphocyte sequestration in the lymph nodes similar to that observed with S1P1 agonists while upregulating S1P1 on lymphocytes and endothelial cells. Additionally, we show that S1P1 antagonism reverses experimental autoimmune encephalomyelitis in mice without acting on S1P1 expressed within the central nervous system, demonstrating that lymphocyte sequestration via S1P1 antagonism is sufficient to alleviate autoimmune pathology. PMID:23204443

  9. Sphingosine 1-phosphate receptor 1 (S1P(1)) upregulation and amelioration of experimental autoimmune encephalomyelitis by an S1P(1) antagonist.

    PubMed

    Cahalan, Stuart M; Gonzalez-Cabrera, Pedro J; Nguyen, Nhan; Guerrero, Miguel; Cisar, Elizabeth A George; Leaf, Nora B; Brown, Steven J; Roberts, Edward; Rosen, Hugh

    2013-02-01

    Sphingosine 1-phosphate receptor 1 (S1P(1)) is a G protein-coupled receptor that is critical for proper lymphocyte development and recirculation. Agonists to S1P(1) are currently in use clinically for the treatment of multiple sclerosis, and these drugs may act on both S1P(1) expressed on lymphocytes and S1P(1) expressed within the central nervous system. Agonists to S1P(1) and deficiency in S1P(1) both cause lymphocyte sequestration in the lymph nodes. In the present study, we show that S1P(1) antagonism induces lymphocyte sequestration in the lymph nodes similar to that observed with S1P(1) agonists while upregulating S1P(1) on lymphocytes and endothelial cells. Additionally, we show that S1P(1) antagonism reverses experimental autoimmune encephalomyelitis in mice without acting on S1P(1) expressed within the central nervous system, demonstrating that lymphocyte sequestration via S1P(1) antagonism is sufficient to alleviate autoimmune pathology.

  10. Diffusion barriers

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.

    1983-01-01

    The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

  11. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  12. Polarimetric studies of comet C/2009 P1 (Garradd)

    NASA Astrophysics Data System (ADS)

    Das, H. S.; Medhi, B. J.; Wolf, S.; Bertrang, G.; Deb Roy, P.; Chakraborty, A.

    2013-12-01

    We present the optical imaging polarimetric observations of comet C/2009 P1 (Garradd) at three different phase angles e.g. 28.2°, 28.1° and 21.6°. The observations were carried out using the Inter University Centre for Astronomy and Astrophysics (IUCAA) Faint Object Spectrograph and Camera mounted on Cassegrain focus of the 2 m telescope of IGO, IUCAA, Pune, in Rcomet, R photometric bands, on 2012 March 21 and 22 and Aryabhatta Research Institute of observational sciencES (ARIES) Imaging Polarimeter mounted on Cassegrain focus of the 1.04 m Sampurnanand Telescope of ARIES, Nainital, in R photometric band, on 2012 May 23. We show the presence of a jet activity in the rotational-gradient-treated image of comet Garradd at phase angle 28.1°. These jets are mainly oriented towards the Sun and extended up to ˜5100 km from the cometary photocentre. The antisolar extension of the jet seems to be fainter, which is extended up to ˜1800 km. It is found that the comet Garradd shows negative polarization at phase angle 21.6°. The degree of polarization derived for Garradd is in good agreement with other comets at nearly similar phase angles e.g. comets 67P/Churyumov-Gerasimenko, 22P/Kopff, 1P/Halley, C/1990 K1 (Levy), 4P/Faye and C/1995 O1 (Hale-Bopp) at phase angle ˜28°, and 47P/Ashbrook-Jackson at phase angle ˜21.6°, respectively. It is also found that the degree of polarization of dusty coma of comet Garradd at phase angle ˜28° is high but not as high as in the case of comet Hale-Bopp.

  13. Diffuser Test

    NASA Image and Video Library

    2007-09-13

    Tests begun at Stennis Space Center's E Complex Sept. 13 evaluated a liquid oxygen lead for engine start performance, part of the A-3 Test Facility Subscale Diffuser Risk Mitigation Project at SSC's E-3 Test Facility. Phase 1 of the subscale diffuser project, completed Sept. 24, was a series of 18 hot-fire tests using a 1,000-pound liquid oxygen and gaseous hydrogen thruster to verify maximum duration and repeatability for steam generation supporting the A-3 Test Stand project. The thruster is a stand-in for NASA's developing J-2X engine, to validate a 6 percent scale version of A-3's exhaust diffuser. Testing the J-2X at altitude conditions requires an enormous diffuser. Engineers will generate nearly 4,600 pounds per second of steam to reduce pressure inside A-3's test cell to simulate altitude conditions. A-3's exhaust diffuser has to be able to withstand regulated pressure, temperatures and the safe discharge of the steam produced during those tests. Before the real thing is built, engineers hope to work out any issues on the miniature version. Phase 2 testing is scheduled to begin this month.

  14. 26 CFR 31.3402(p)-1T - Voluntary Withholding Agreements (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...). 31.3402(p)-1T Section 31.3402(p)-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... COLLECTION OF INCOME TAX AT SOURCE Collection of Income Tax at Source § 31.3402(p)-1T Voluntary Withholding Agreements (temporary). (a)-(b) For further guidance, see § 31.3402(p)-1(a) and (b). (c) Other payments....

  15. Defusing Diffusion

    ERIC Educational Resources Information Center

    Dou, Remy; Hogan, DaNel; Kossover, Mark; Spuck, Timothy; Young, Sarah

    2013-01-01

    Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion…

  16. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.

    1977-01-01

    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  17. Defusing Diffusion

    ERIC Educational Resources Information Center

    Dou, Remy; Hogan, DaNel; Kossover, Mark; Spuck, Timothy; Young, Sarah

    2013-01-01

    Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion…

  18. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.

    1977-01-01

    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  19. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy.

    PubMed

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N; Crowley, Paula J; Brady, L Jeannine; Long, Joanna R

    2016-02-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ~57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin.

  20. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy

    PubMed Central

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N.; Crowley, Paula J.; Brady, L. Jeannine; Long, Joanna R.

    2016-01-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ~57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to 1) globally characterize cell walls isolated from a Gram-positive bacterium and 2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin. PMID:26837620

  1. Diffusion bonding

    DOEpatents

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  2. Highly selective and potent agonists of sphingosine-1-phosphate 1 (S1P1) receptor.

    PubMed

    Vachal, Petr; Toth, Leslie M; Hale, Jeffrey J; Yan, Lin; Mills, Sander G; Chrebet, Gary L; Koehane, Carol A; Hajdu, Richard; Milligan, James A; Rosenbach, Mark J; Mandala, Suzanne

    2006-07-15

    Novel series of sphingosine-1-phosphate (S1P) receptor agonists were developed through a systematic SAR aimed to achieve high selectivity for a single member of the S1P family of receptors, S1P1. The optimized structure represents a highly S1P1-selective and efficacious agonist: S1P1/S1P2, S1P1/S1P3, S1P1/S1P4>10,000-fold, S1P1/S1P5>600-fold, while EC50 (S1P1) <0.2 nM. In vivo experiments are consistent with S1P1 receptor agonism alone being sufficient for achieving desired lymphocyte-lowering effect.

  3. 26 CFR 31.3306(p)-1 - Employees of related corporations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Employees of related corporations. 31.3306(p)-1 Section 31.3306(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Federal Unemployment Tax Act (Chapter 23, Internal Revenue Code of 1954) § 31.3306(p)-1...

  4. 26 CFR 1.409(p)-1 - Prohibited allocation of securities in an S corporation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... corporation. 1.409(p)-1 Section 1.409(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Plans, Etc. § 1.409(p)-1 Prohibited allocation of securities in an S corporation. (a) Organization of this section and definition—(1) Organization of this section. Section 409(p) applies if a...

  5. 26 CFR 31.3306(p)-1 - Employees of related corporations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Employees of related corporations. 31.3306(p)-1 Section 31.3306(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Federal Unemployment Tax Act (Chapter 23, Internal Revenue Code of 1954) § 31.3306(p)-1...

  6. 26 CFR 1.72(p)-1 - Loans treated as distributions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Loans treated as distributions. 1.72(p)-1 Section 1.72(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.72(p)-1...

  7. 26 CFR 1.409(p)-1 - Prohibited allocation of securities in an S corporation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... corporation. 1.409(p)-1 Section 1.409(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Plans, Etc. § 1.409(p)-1 Prohibited allocation of securities in an S corporation. (a) Organization of this section and definition—(1) Organization of this section. Section 409(p) applies if a...

  8. 26 CFR 31.3306(p)-1 - Employees of related corporations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Employees of related corporations. 31.3306(p)-1 Section 31.3306(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Federal Unemployment Tax Act (Chapter 23, Internal Revenue Code of 1954) § 31.3306(p)-1...

  9. 26 CFR 31.3306(p)-1 - Employees of related corporations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Employees of related corporations. 31.3306(p)-1 Section 31.3306(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SOURCE Federal Unemployment Tax Act (Chapter 23, Internal Revenue Code of 1954) § 31.3306(p)-1...

  10. 26 CFR 1.409(p)-1 - Prohibited allocation of securities in an S corporation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... corporation. 1.409(p)-1 Section 1.409(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Plans, Etc. § 1.409(p)-1 Prohibited allocation of securities in an S corporation. (a) Organization of this section and definition—(1) Organization of this section. Section 409(p) applies if a...

  11. 26 CFR 1.72(p)-1 - Loans treated as distributions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Loans treated as distributions. 1.72(p)-1 Section 1.72(p)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.72(p)-1...

  12. DIFFUSION PUMP

    DOEpatents

    Levenson, L.

    1963-09-01

    A high-vacuum diffusion pump is described, featuring a novel housing geometry for enhancing pumping speed. An upright, cylindrical lower housing portion is surmounted by a concentric, upright, cylindrical upper housing portion of substantially larger diameter; an uppermost nozzle, disposed concentrically within the upper portion, is adapted to eject downwardly a conical sheet of liquid outwardly to impinge upon the uppermost extremity of the interior wall of the lower portion. Preferably this nozzle is mounted upon a pedestal rising coaxially from within the lower portion and projecting up into said upper portion. (AEC)

  13. The glycosphingolipid P1 is an ovarian cancer-associated carbohydrate antigen involved in migration

    PubMed Central

    Jacob, F; Anugraham, M; Pochechueva, T; Tse, B W C; Alam, S; Guertler, R; Bovin, N V; Fedier, A; Hacker, N F; Huflejt, M E; Packer, N; Heinzelmann-Schwarz, V A

    2014-01-01

    Background: The level of plasma-derived naturally circulating anti-glycan antibodies (AGA) to P1 trisaccharide has previously been shown to significantly discriminate between ovarian cancer patients and healthy women. Here we aim to identify the Ig class that causes this discrimination, to identify on cancer cells the corresponding P1 antigen recognised by circulating anti-P1 antibodies and to shed light into the possible function of this glycosphingolipid. Methods: An independent Australian cohort was assessed for the presence of anti-P1 IgG and IgM class antibodies using suspension array. Monoclonal and human derived anti-glycan antibodies were verified using three independent glycan-based immunoassays and flow cytometry-based inhibition assay. The P1 antigen was detected by LC-MS/MS and flow cytometry. FACS-sorted cell lines were studied on the cellular migration by colorimetric assay and real-time measurement using xCELLigence system. Results: Here we show in a second independent cohort (n=155) that the discrimination of cancer patients is mediated by the IgM class of anti-P1 antibodies (P=0.0002). The presence of corresponding antigen P1 and structurally related epitopes in fresh tissue specimens and cultured cancer cells is demonstrated. We further link the antibody and antigen (P1) by showing that human naturally circulating and affinity-purified anti-P1 IgM isolated from patients ascites can bind to naturally expressed P1 on the cell surface of ovarian cancer cells. Cell-sorted IGROV1 was used to obtain two study subpopulations (P1-high, 66.1% and P1-low, 33.3%) and observed that cells expressing high P1-levels migrate significantly faster than those with low P1-levels. Conclusions: This is the first report showing that P1 antigen, known to be expressed on erythrocytes only, is also present on ovarian cancer cells. This suggests that P1 is a novel tumour-associated carbohydrate antigen recognised by the immune system in patients and may have a role in cell

  14. Dose of house dust mite antigen (P1) inhaled by infants aged one month

    SciTech Connect

    Carswell, F.; Clark, J.; Robinson, P.; Platts-Mills, T.A.

    1983-11-01

    A survey of the habitats occupied by 12 infants of one month of age revealed that approximately 10% of their day was spent in conditions of potential exposure to the major (P1) allergen of the house dust mite, Dermatophagoides pteronyssinus. A respiratory pump which reproduced the minute ventilation of an infant was placed in representative infant habitats. The P1 allergen trapped by the filter in this pump was measured as an estimate of infants' allergen intake. Detectable P1 intake was only present when there was active air disturbance (bed making and vacuuming). The average P1 intake was approximately 3 ng P1/24 hours. Comparison of this P1 intake with that which sensitizes in other situations suggests that it is usually inadequate to sensitize infants.

  15. Discovery of a novel series of potent S1P1 agonists.

    PubMed

    Crosignani, Stefano; Bombrun, Agnes; Covini, David; Maio, Maurizio; Marin, Delphine; Quattropani, Anna; Swinnen, Dominique; Simpson, Don; Sauer, Wolfgang; Françon, Bernard; Martin, Thierry; Cambet, Yves; Nichols, Anthony; Martinou, Isabelle; Burgat-Charvillon, Fabienne; Rivron, Delphine; Donini, Cristina; Schott, Olivier; Eligert, Valerie; Novo-Perez, Laurence; Vitte, Pierre-Alain; Arrighi, Jean-François

    2010-03-01

    The discovery of a novel series of S1P1 agonists is described. Starting from a micromolar HTS positive, iterative optimization gave rise to several single-digit nanomolar S1P1 agonists. The compounds were able to induce internalization of the S1P1 receptor, and a selected compound was shown to be able to induce lymphopenia in mice after oral dosing.

  16. Characterization of the P1 protein and coding region of the zucchini yellow mosaic virus.

    PubMed

    Wisler, G C; Purcifull, D E; Hiebert, E

    1995-01-01

    The nucleotide sequence of the 5'-terminal P1 coding region of an aphid-transmissible isolate of zucchini yellow mosaic virus (ZYMV; strain FL/AT), a mild isolate (strain MD) and a severe isolate (strain SV), all from Florida, were compared with two other ZYMV isolates. The ZYMV MD and SV isolates and an isolate from California (ZYMV CA) had 95-98% sequence similarities to FL/AT, whereas an isolate from Reunion Island (ZYMV RU) had a 60% sequence similarity to FL/AT. ZYMV MD had an 18 nucleotide insert following the start codon of the P1 coding region. The P1 proteins of all ZYMV isolates shared conserved amino acids in areas of the C terminus similar to those reported for other potyviruses. Polyclonal antisera were prepared to the P1 proteins of ZYMV FL/AT and RU expressed in Escherichia coli. The FL/AT and RU P1 antisera showed varying degrees of reactivity in Western blots with extracts of pumpkin (Cucurbita pepo L.) singly infected with a number of distinct ZYMV isolates. The reaction of the FL/AT P1 antiserum with isolate RU-infected tissue extracts was very weak compared to the homologous reaction. Neither antiserum reacted with extracts from plants singly infected with three other potyviruses, a potexvirus, or a cucumovirus. The P1 proteins of ZYMV isolates ranged in molecular mass from 33 kDa to 35 kDa. The P1 protein of strain MD was larger (35 kDa) than that of FL/AT (34 kDa). Indirect immunofluorescence tests with FL/AT P1 antiserum indicated that the P1 protein aggregates in ZYMV-infected tissues. The antisera to the ZYMV P1 proteins have potential as serological probes for identifying ZYMV and for distinguishing ZYMV isolates by immunoblotting.

  17. Nutrient sequestration from wastewater by using zeolite Na-P1 synthesized from coal fly ash.

    PubMed

    He, Hongfu; Xu, Suyun; Han, Runqi; Wang, Qiuchen

    2017-04-01

    The objective of this study is to investigate the cation exchange property of the product zeolite Na-P1 (Z-P1) synthesized from coal fly ash (FA) by the alkali hydrothermal reaction, and to evaluate the water purification ability for the simultaneous removal of ammonium and phosphate. High-purity Z-P1 was obtained by optimizing the reaction conditions of aging time and crystallization temperature, and using FA particles of uniform particle size. Kinetic ammonium sorption experiments with Z-P1 were well described by both the Langmuir and Freundlich models, and the maximum adsorption capacity of the Z-P1 was 23.15 mg/g. Moreover, in order to determine the effect of magnesium intervention on the ammonium and phosphate removal from simulated swine wastewater, two forms of magnesium were studied, that is Mg-saturated Z-P1 and direct use of Mg(2+) source with Z-P1, as compared with the control (sole Z-P1). Results showed that Mg(2+) addition could improve phosphate removal efficiency significantly by forming struvite. Furthermore, dosing Z-P1 with dissolved Mg(2+) was better than Mg-saturated Z-P1 in terms of ammonium and phosphate removal efficiencies, and the preparation cost. When dosing 20 g/L Z-P1 with 4 mM Mg(2+), ammonium and phosphate removal efficiencies reached 65.2% and 92.3% after 30 min.

  18. Diffusion archeology for diffusion progression history reconstruction.

    PubMed

    Sefer, Emre; Kingsford, Carl

    2016-11-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.

  19. A genome-wide regulatory framework identifies maize Pericarp Color1 (P1) controlled genes

    USDA-ARS?s Scientific Manuscript database

    P1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues. Using genome-wide expression analyses (RNA-Seq) in pericarps and silks of plants with contrasting P1 alleles combin...

  20. Including an Exam P/1 Prep Course in a Growing Actuarial Science Program

    ERIC Educational Resources Information Center

    Wakefield, Thomas P.

    2014-01-01

    The purpose of this article is to describe the actuarial science program at our university and the development of a course to enhance students' problem solving skills while preparing them for Exam P/1 of the Society of Actuaries (SOA) and the Casualty Actuary Society (CAS). The Exam P/1 prep course, formally titled Mathematical Foundations of…

  1. Complete Genome Sequence of the Pyrene-Degrading Bacterium Cycloclasticus sp. Strain P1

    PubMed Central

    Lai, Qiliang; Li, Weiwei; Wang, Baojiang; Yu, Zhiwei

    2012-01-01

    Cycloclasticus sp. strain P1 was isolated from deep-sea sediments of the Pacific Ocean and characterized as a unique bacterium in the degradation of pyrene, a four-ring polycyclic aromatic hydrocarbon (PAH). Here we report the complete genome of P1 and genes associated with PAH degradation. PMID:23144416

  2. Including an Exam P/1 Prep Course in a Growing Actuarial Science Program

    ERIC Educational Resources Information Center

    Wakefield, Thomas P.

    2014-01-01

    The purpose of this article is to describe the actuarial science program at our university and the development of a course to enhance students' problem solving skills while preparing them for Exam P/1 of the Society of Actuaries (SOA) and the Casualty Actuary Society (CAS). The Exam P/1 prep course, formally titled Mathematical Foundations of…

  3. [Structure and function of heavy metal transporter P(1B)-ATPase in plant: a review].

    PubMed

    Zhang, Yuxiu; Zhang, Yuanya; Sun, Tao; Chai, Tuanyao

    2010-06-01

    The regulation of the heavy-metal accumulation in vivo for plant survival is very complex. The metal cation transporter plays key roles in the metabolic process. P(1B)-ATPases are the only subgroup of P-ATPases that contribute to heavy metal homeostasis presented in most organisms. Arabidopsis thaliana contains eight genes encoding P(1B)-ATPases. The current reports show that the functions of P(1B)-ATPases are involved in maintaining metal homeostasis, transporting and detoxification in plants. P(1B)-ATPases not only mediated metal ion mobilization and uptake in roots, but also contribute to the metal transport, storage and tolerance in shoots, especially in heavy metal hyperaccumulators. In this paper, we reviewed and discussed the evolution, classification, structure and function of P(1B)-ATPases in plants. HMAs-transgenic manipulation could be a feasible approach for phytoremediation and mineral nutrition fortification.

  4. NIST Diffusion Data Center

    National Institute of Standards and Technology Data Gateway

    NIST Diffusion Data Center (Web, free access)   The NIST Diffusion Data Center is a collection of over 14,100 international papers, theses, and government reports on diffusion published before 1980.

  5. Parallel flow diffusion battery

    DOEpatents

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  6. Parallel flow diffusion battery

    DOEpatents

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  7. Pathophysiological Consequences of a Break in S1P1-Dependent Homeostasis of Vascular Permeability Revealed by S1P1 Competitive Antagonism

    PubMed Central

    Bigaud, Marc; Dincer, Zuhal; Bollbuck, Birgit; Dawson, Janet; Beckmann, Nicolau; Beerli, Christian; Fishli-Cavelti, Gina; Nahler, Michaela; Angst, Daniela; Janser, Philipp; Otto, Heike; Rosner, Elisabeth; Hersperger, Rene; Bruns, Christian; Quancard, Jean

    2016-01-01

    Rational Homeostasis of vascular barriers depends upon sphingosine 1-phosphate (S1P) signaling via the S1P1 receptor. Accordingly, S1P1 competitive antagonism is known to reduce vascular barrier integrity with still unclear pathophysiological consequences. This was explored in the present study using NIBR-0213, a potent and selective S1P1 competitive antagonist. Results NIBR-0213 was tolerated at the efficacious oral dose of 30 mg/kg BID in the rat adjuvant-induced arthritis (AiA) model, with no sign of labored breathing. However, it induced dose-dependent acute vascular pulmonary leakage and pleural effusion that fully resolved within 3–4 days, as evidenced by MRI monitoring. At the supra-maximal oral dose of 300 mg/kg QD, NIBR-0213 impaired lung function (with increased breathing rate and reduced tidal volume) within the first 24 hrs. Two weeks of NIBR-0213 oral dosing at 30, 100 and 300 mg/kg QD induced moderate pulmonary changes, characterized by alveolar wall thickening, macrophage accumulation, fibrosis, micro-hemorrhage, edema and necrosis. In addition to this picture of chronic inflammation, perivascular edema and myofiber degeneration observed in the heart were also indicative of vascular leakage and its consequences. Conclusions Overall, these observations suggest that, in the rat, the lung is the main target organ for the S1P1 competitive antagonism-induced acute vascular leakage, which appears first as transient and asymptomatic but could lead, upon chronic dosing, to lung remodeling with functional impairments. Hence, this not only raises the question of organ specificity in the homeostasis of vascular barriers, but also provides insight into the pre-clinical evaluation of a potential safety window for S1P1 competitive antagonists as drug candidates. PMID:28005953

  8. FRACTIONAL PEARSON DIFFUSIONS.

    PubMed

    Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla

    2013-07-15

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change.

  9. FRACTIONAL PEARSON DIFFUSIONS

    PubMed Central

    Leonenko, Nikolai N.; Meerschaert, Mark M.

    2013-01-01

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change. PMID:23626377

  10. Characterization of the enterovirus 71 P1 polyprotein expressed in Pichia pastor as a candidate vaccine

    PubMed Central

    Han, Xue; Ying, Xiao-ling; Zhou, Shi-li; Han, Tao; Huang, Hao; Jin, Qi; Yang, Fan; Sun, Qi-ying; Sun, Xian-xun

    2014-01-01

    Human enterovirus 71 (EV71) plays an important role in hand, foot, and mouth disease (HFMD), which recently caused the death of hundreds of children in the Asia-Pacific region. However, there are no specific treatments available for EV71 infections; thus, a safe and effective vaccine is needed urgently. In this study, we developed an effective and economical method for producing EV71 polyprotein (P1 protein) in Pichia pastoris. Furthermore, we evaluated the potential of P1 protein as a candidate vaccine against EV71 virus. The data revealed that P1 protein induced persistent high cross-neutralization antibodies for different EV71 subtypes, and elicited significant splenocyte proliferation. The high levels of interleukin-10(IL-10) and interferon-gamma (IFN-γ) showed that P1 protein induced Th1 and Th2 immune responses. Interestingly, vaccinating female mice with the P1 protein conferred cross-protection against different EV71 subtypes to their neonatal offspring.Compared with heat-inactivated EV71, the P1 protein elicited improved humoral and cellular immune responses and showed good cross-protection with different EV71 subtypes. Therefore, the EV71-P1 protein produced by P. pastoris is a promising candidate vaccine against EV71. PMID:25424925

  11. HAT-P-1: A Direct Glimpse into the Atmosphere of a Hot Jupiter

    NASA Astrophysics Data System (ADS)

    Holman, Matthew

    2009-07-01

    The HATNet project has discovered a transiting planet that is an extremely valuable target for reflected light observations {Bakos et al. 2006}. HAT-P-1b, with mass M_p=0.53 +/- 0.04 M_Jup, and radius R_p=1.20 +/- 0.05 R_Jup {Winn et al. 2007}, has a density comparable to that of HD 209458b. However, HAT-P-1b's P=4.46536 day orbital period is longer than that of HD 209458b. It is expected that the cloud composition and particulate size distribution of HAT-P-1b will differ from that of HD 209458b, due to the larger semimajor axis and lower effective temperature of HAT-P-1b. The resulting geometric albedo for HAT-P-1b should be larger than that of HD 209458b. Furthermore, HAT-P-1 orbits one component of a wide binary {ADS 16402A and ADS 16402B are G0V stars with 11.2" at 1.39 pc}, making this an ideal target for ultra-precise differential photometry. Therefore, we propose ACS/HRC slitless grism photometry near times of its secondary eclipse to make the first detection of reflected light from an extrasolar planet.Note: this program was awarded DD time in Cycle 15 but the observations were not executed before the ACS failed.Holman and Bakos are co-PIs on this proposal.

  12. Host range diversification within the IncP-1 plasmid group

    PubMed Central

    Yano, Hirokazu; Rogers, Linda M.; Knox, Molly G.; Heuer, Holger; Smalla, Kornelia; Brown, Celeste J.

    2013-01-01

    Broad-host-range plasmids play a critical role in the spread of antibiotic resistance and other traits. In spite of increasing information about the genomic diversity of closely related plasmids, the relationship between sequence divergence and host range remains unclear. IncP-1 plasmids are currently classified into six subgroups based on the genetic distance of backbone genes. We investigated whether plasmids from two subgroups exhibit a different host range, using two IncP-1γ plasmids, an IncP-1β plasmid and their minireplicons. Efficiencies of plasmid establishment and maintenance were compared using five species that belong to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. The IncP-1β plasmid replicated and persisted in all five hosts in the absence of selection. Of the two IncP-1γ plasmids, both were unable to replicate in alphaproteobacterial host Sphingobium japonicum, and one established itself in Agrobacterium tumefaciens but was very unstable. In contrast, both IncP-1γ minireplicons, which produced higher levels of replication initiation protein than the wild-type plasmids, replicated in all strains, suggesting that poor establishment of the native plasmids is in part due to suboptimal replication initiation gene regulation. The findings suggest that host ranges of distinct IncP-1 plasmids only partially overlap, which may limit plasmid recombination and thus result in further genome divergence. PMID:24002747

  13. Differences in the P1' substrate specificities of pepsin A and chymosin.

    PubMed

    Kageyama, Hakuto; Ueda, Hiroshi; Tezuka, Takafumi; Ogasawara, Asami; Narita, Yuichi; Kageyama, Takashi; Ichinose, Masao

    2010-02-01

    Porcine pepsin A and bovine chymosin are typical models of aspartic proteinases. The hydrolytic specificities of these proteinases, along with those of human pepsin A and monkey chymosin, were investigated with 29 peptide substrates that included various P1' variants of seven parent peptides. From these peptides, AFPLEF downward arrow FREL was preferred by pepsin A and chymosin, while its P1' variant, AFPLEF downward arrow EREL was preferred by bovine chymosin. Porcine and human pepsin A showed similar hydrolytic specificities, strongly preferring a hydrophobic/aromatic residue at P1' of any type of peptide. This specificity is well explained by the very hydrophobic nature of the S1' subsite that consists of Tyr(189), Ile(213), Ile(300), Met(289), Val/Leu(291) and Leu(298). The first three residues are well conserved in pepsin family enzymes. Although bovine and monkey chymosin showed similar P1' specificity, bovine chymosin preferred peptides having Glu at P1', while monkey chymosin preferred peptides having Lys at P1'. The dual characteristics of chymosin are due to the occurrence of polar/charged residues in the S1' subsite, such as Glu/Asp(289), Gln(298) and Lys/Gln(299), which are different from the S1' subsite of pepsin A. Molecular models suggest that Glu in position 289 of bovine chymosin and Asp in position 289 of monkey chymosin are responsible for the difference in P1' specificities between the chymosins.

  14. A phage P1 function that stimulates homologous recombination of the Escherichia coli chromosome.

    PubMed

    Windle, B E; Hays, J B

    1986-06-01

    Recombination between two different defective lacZ genes in the Escherichia coli chromosome (lac- X lac- recombination) was stimulated 2- to 8-fold by prophage P1, depending on the nature of the phage c1 repressor. The P1 BamHI restriction fragment B8 in a lambda-P1:B8 hybrid phage, stimulated lac- X lac- recombination 90-fold in the absence of P1 repressor. A gene necessary for recombination enhancement, designated ref, was localized to one end of B8. Ref expression from lambda-P1:B8 was repressed in trans by a P1 c+ prophage. Two P1 regulatory mutations, bof and lxc, derepressed prophage expression of ref and depressed a prophage function that complemented an E. coli mutant (ssb) deficient in the single-stranded DNA binding protein. Ref stimulation was dependent on preexisting E. coli recombination functions (RecA-RecBC and RecA-RecF). However, other (phage and plasmid) recombination processes involving these functions were not stimulated. ref::Tn5 phages plated and formed lysogens normally. Thus ref appears to be an integral, but not essential, phage gene that stimulates recombination of the host chromosome specifically.

  15. A phage P1 function that stimulates homologous recombination of the Escherichia coli chromosome.

    PubMed Central

    Windle, B E; Hays, J B

    1986-01-01

    Recombination between two different defective lacZ genes in the Escherichia coli chromosome (lac- X lac- recombination) was stimulated 2- to 8-fold by prophage P1, depending on the nature of the phage c1 repressor. The P1 BamHI restriction fragment B8 in a lambda-P1:B8 hybrid phage, stimulated lac- X lac- recombination 90-fold in the absence of P1 repressor. A gene necessary for recombination enhancement, designated ref, was localized to one end of B8. Ref expression from lambda-P1:B8 was repressed in trans by a P1 c+ prophage. Two P1 regulatory mutations, bof and lxc, derepressed prophage expression of ref and depressed a prophage function that complemented an E. coli mutant (ssb) deficient in the single-stranded DNA binding protein. Ref stimulation was dependent on preexisting E. coli recombination functions (RecA-RecBC and RecA-RecF). However, other (phage and plasmid) recombination processes involving these functions were not stimulated. ref::Tn5 phages plated and formed lysogens normally. Thus ref appears to be an integral, but not essential, phage gene that stimulates recombination of the host chromosome specifically. PMID:3012538

  16. Identification and Characterization of the Single-Stranded DNA-Binding Protein of Bacteriophage P1

    PubMed Central

    Lehnherr, Hansjörg; Bendtsen, Jannick D.; Preuss, Fabian; Ilyina, Tatiana V.

    1999-01-01

    The genome of bacteriophage P1 harbors a gene coding for a 162-amino-acid protein which shows 66% amino acid sequence identity to the Escherichia coli single-stranded DNA-binding protein (SSB). The expression of the P1 gene is tightly regulated by P1 immunity proteins. It is completely repressed during lysogenic growth and only weakly expressed during lytic growth, as assayed by an ssb-P1/lacZ fusion construct. When cloned on an intermediate-copy-number plasmid, the P1 gene is able to suppress the temperature-sensitive defect of an E. coli ssb mutant, indicating that the two proteins are functionally interchangeable. Many bacteriophages and conjugative plasmids do not rely on the SSB protein provided by their host organism but code for their own SSB proteins. However, the close relationship between SSB-P1 and the SSB protein of the P1 host, E. coli, raises questions about the functional significance of the phage protein. PMID:10515938

  17. The Hypervariable Amino-Terminus of P1 Protease Modulates Potyviral Replication and Host Defense Responses

    PubMed Central

    Pasin, Fabio; Simón-Mateo, Carmen; García, Juan Antonio

    2014-01-01

    The replication of many RNA viruses involves the translation of polyproteins, whose processing by endopeptidases is a critical step for the release of functional subunits. P1 is the first protease encoded in plant potyvirus genomes; once activated by an as-yet-unknown host factor, it acts in cis on its own C-terminal end, hydrolyzing the P1-HCPro junction. Earlier research suggests that P1 cooperates with HCPro to inhibit host RNA silencing defenses. Using Plum pox virus as a model, we show that although P1 does not have a major direct role in RNA silencing suppression, it can indeed modulate HCPro function by its self-cleavage activity. To study P1 protease regulation, we used bioinformatic analysis and in vitro activity experiments to map the core C-terminal catalytic domain. We present evidence that the hypervariable region that precedes the protease domain is predicted as intrinsically disordered, and that it behaves as a negative regulator of P1 proteolytic activity in in vitro cleavage assays. In viral infections, removal of the P1 protease antagonistic regulator is associated with greater symptom severity, induction of salicylate-dependent pathogenesis-related proteins, and reduced viral loads. We suggest that fine modulation of a viral protease activity has evolved to keep viral amplification below host-detrimental levels, and thus to maintain higher long-term replicative capacity. PMID:24603811

  18. Oligosaccharide ligands for NKR-P1 protein activate NK cells and cytotoxicity

    NASA Astrophysics Data System (ADS)

    Bezouška, Karel; Yuen, Chun-Ting; O'Brien, Jacqui; Childs, Robert A.; Chai, Wengang; Lawson, Alexander M.; Drbal, Karel; Fišerová, Anna; Posíšil, Miloslav; Feizi, Ten

    1994-11-01

    A diversity of high-affinity Oligosaccharide ligands are identified for NKR-P1, a membrane protein on natural killer (NK) cells which contains an extracellular Ca2+-dependent lectin domain. Interactions of such oligosaccharides on the target cell surface with NKR-P1 on the killer cell surface are crucial both for target cell recognition and for delivery of stimulatory or inhibitory signals linked to the NK cytolytic machinery. NK-resistant tumour cells are rendered susceptible by preincubation with liposomes expressing NKR-P1 ligands, suggesting that purging of tumour or virally infected cells in vivo may be a therapeutic possibility.

  19. Transmission spectrum of HAT-P-1b as observed with the Hale telescope

    NASA Astrophysics Data System (ADS)

    Chen, Guo; van Boekel, Roy; Madhusudhan, Nikku; Wang, Hongchi; Henning, Thomas

    2013-07-01

    We observed two primary transits of the hot Jupiter HAT-P-1b using the DBSP and TSpec mounted on the Hale 200-inch telescope in September 2012. This work aims at constructing the first optical-to-NIR transmission spectrum for HAT-P-1b from the ground, and thereby revealing its atmospheric properties. We have potentially detected the potassium absorption in HAT-P-1b's atmosphere, and greatly improved the precision of transit ephemeris and system parameters. Detail atmospheric spectral retrieval modelling is still in progress.

  20. Non-covalent thrombin inhibitors featuring P3-heterocycles with P1-bicyclic arginine surrogates.

    PubMed

    Cui, Jingrong Jean; Araldi, Gian-Luca; Reiner, John E; Reddy, Komandla Malla; Kemp, Scott J; Ho, Jonathan Z; Siev, Daniel V; Mamedova, Lala; Gibson, Tony S; Gaudette, John A; Minami, Nathaniel K; Anderson, Susanne M; Bradbury, Annette E; Nolan, Thomas G; Semple, J Edward

    2002-10-21

    Novel, potent, and highly selective classes of thrombin inhibitors were identified, which resulted from judicious combination of P4-aromatics and P2-P3-heterocyclic dipeptide surrogates with weakly basic (calcd pKa approximately non-basic-8.6) bicyclic P1-arginine mimics. The design, synthesis, and biological activity of achiral, non-covalent, orally bioavailable inhibitors NC1-NC44 featuring P1-indazoles, benzimidazoles, indoles, benzotriazoles, and aminobenzisoxazoles is disclosed.

  1. Synthesis of the Bycroft-Gowland structure of micrococcin P1.

    PubMed

    Ciufolini, M A; Shen, Y C

    1999-12-02

    [formula: see text] We describe the chemical synthesis of the accepted structure of micrococcin P1, a member of the thiostrepton group of antibiotics, and we show that this architecture does not correspond to that of the natural product. Methods developed during the present study should greatly facilitate ongoing efforts centering on the determination of the actual structure of microccin P1, in addition to being applicable to the synthesis of more complex thiostrepton congeners.

  2. Design and Synthesis of Hydroxyethylene-Based BACE-1 Inhibitors Incorporating Extended P1 Substituents

    PubMed Central

    Sandgren, Veronica; Bäck, Marcus; Kvarnström, Ingemar; Dahlgren, Anders

    2013-01-01

    Novel BACE-1 inhibitors with a hydroxyethylene central core have been developed. Modified P1´ and extended P1 substituents were incorporated with the aim to explore potential interactions with the S1´ and the S1-S3 pocket, respectively, of BACE-1. Inhibitors were identified displaying IC50 values in the nanomolar range, i.e. 69 nM for the most potent compound. Possible inhibitor interactions with the enzyme are also discussed. PMID:23585822

  3. Comparison of buffers for extraction of mite allergen der p 1 from dust.

    PubMed

    Prester, Ljerka; Kovačić, Jelena; Macan, Jelena

    2012-09-01

    Der p 1 is the main allergen of house dust mite Dermatophagoides pteronyssinus, which has routinely been detected in residential dust. However, the procedure for extracting Der p 1 from reservoir dust has not been well defined. The aim of this study was to compare Der p 1 mass fractions in dust extracts prepared using the following extraction buffers: phosphate (pH 7.4), borate (pH 8.0), and ammonium bicarbonate (pH 8.0), all with 0.05 % Tween 20. Twenty-eight dust samples were divided into three aliquots and each portion was extracted with one of the three buffers at room temperature. Der p 1 mass fractions were measured in a total of 84 dust extracts using the enzyme immunoassay (range: 0.1 μg g-1 to 7.53 μg g-1). Statistical methods including intraclass correlation showed a high agreement between Der p 1 mass fractions irrespective of the extracting medium. Our results suggest that all three buffers are suitable for the extraction of mite allergens and routine Der p 1 analysis in dust.

  4. Recombination between plasmids of incompatibility groups P-1 and P-2.

    PubMed Central

    Jacoby, G A; Jacob, A E; Hedges, R W

    1976-01-01

    R plasmids of incompatibility group P-2 are readily transmissible between Pseudomonas strains, but not to Escherichia coli or other enterobacteria, whereas those of group P-1 have a broad host range. Pseudomonas aeruginosa donor strains carrying both a P-1 plasmid (RP1, RP4, or R751) and a P-2 plasmid (pMG1, pMG2, pMG5, or RPL11) were mated with E. coli K-12, and selection was imposed for resistance markers on the P-2 plasmids. Transconjugants were obtained at a low frequency, in which P-2 markers were expressed and were serially transmissible in E. coli together with P-1 markers. These plasmids had P-1 incompatibility properties, conferred susceptibility to phages active on P-1 carrying strains, and behaved on sucrose gradient centrifugation as unimolecular species of higher molecular weights than the P-1 parent. Recombinant plasmid formation was independent of a functional Rec gene in both donor and recipient and, with R751, had a preferred site leading to loss of trimethoprim resistance. Interaction between insertion sequences may be involved. Thus, plasmids of group P-2 can recombine with R factors of another group quite separate in compatibility properties, host range, and pilus type. Formation of such recombinants provides one pathway by which the genetic diversity of plasmids may have evolved. PMID:821925

  5. Cortical auditory evoked potential (P1): a potential objective indicator for auditory rehabilitation outcome.

    PubMed

    Thabet, Mirahan T; Said, Nithreen M

    2012-12-01

    Cortical auditory evoked potentials are a non-invasive tool that can provide objective information on maturation of the auditory pathways. This work was designed to study the role of cortical auditory evoked potential (P1) in assessment of the benefits of amplification and aural rehabilitation in hearing impaired children. The study consisted of 31 children classified into 2 groups. Study group included 18 hearing impaired children ranging in age 4-14 years old and classified into two subgroups according to adequacy of aural rehabilitation. A control group consisted of 13 normal hearing children ranging in age from 5 to 13 years. All children were subjected to history taking, basic audiological evaluation, intelligence quotient and language assessment. Cortical auditory evoked potential (P1) was measured using synthesized speech syllable /da/ as a recording stimulus that was presented binaurally via a loudspeaker. P1 was recorded in all children with significantly prolonged latencies in hearing impaired children with inadequate rehabilitation. P1 latency was correlated to hearing loss duration in hearing impaired children with inadequate aural rehabilitation. Auditory experience was correlated with P1 latency in hearing impaired children with adequate aural rehabilitation. Cortical auditory evoked potential (P1) might provide a clinical tool to monitor aural rehabilitation outcome and to guide intervention choices. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Downregulation of TPTE2P1 Inhibits Migration and Invasion of Gallbladder Cancer Cells.

    PubMed

    Lv, Wenjie; Wang, Lei; Lu, Jianhua; Mu, Jiasheng; Liu, Yingbin; Dong, Ping

    2015-10-01

    Human gallbladder cancer is a rare malignancy disease but having poor prognosis over the world. Previous studies have put forward that PTEN is a tumour suppressor in regulating many cellular processes, similar activities have been observed for its mammal homologue TPTE2. In this study, we attempted to unravel the underlying mechanistic basis of the role of TPTE2 and its pseudogene TPTE2P1 in gallbladder cancer. We employed lentivirus-mediated RNA interference as an efficient tool to silence endogenous TPTE2P1 transcription in the gallbladder cancer cell line GBC-SD/M. The effects of TPTE2P1 on cell migration and invasion were determined by transwell assays. We figured that depletion of TPTE2P1 remarkably inhibited gallbladder cancer cell migration and invasion capacity in vitro and elevated the expression of β-catenin via epithelial-mesenchymal transition signalling. Our findings revealed the functional role of TPTE2P1 in human gallbladder cancer and suggested that TPTE2P1 could serve as a promising therapeutic target and a palliation option in human gallbladder cancer. © 2015 John Wiley & Sons A/S.

  7. One SUMO is sufficient to silence the dimeric potassium channel K2P1

    PubMed Central

    Plant, Leigh D.; Dementieva, Irina S.; Kollewe, Astrid; Olikara, Sonia; Marks, Jeremy D.; Goldstein, Steve A. N.

    2010-01-01

    Small ubiquitin modifier 1 (SUMO1) is shown to regulate K2P1 background channels in the plasma membrane (PM) of live mammalian cells. Confocal microscopy reveals native SUMO1, SAE1, and Ubc9 (the enzymes that activate and conjugate SUMO1) at PM where SUMO1 and expressed human K2P1 are demonstrated to colocalize. Silent K2P1 channels in excised PM patches are activated by SUMO isopeptidase (SENP1) and resilenced by SUMO1. K2P1-Lys274 is crucial: when mutated to Gln, Arg, Glu, Asp, Cys, or Ala, the channels are constitutively active and insensitive to SUMO1 and SENP1. Tandem mass spectrometry confirms conjugation of SUMO1 to the ε-amino group of Lys274 in vitro. FRET microscopy shows that assembly of K2P1 and SUMO1 requires Lys274. Single-particle TIRF microscopy shows that wild-type channels in PM have two K2P1 subunits and assemble with two SUMO1 monomers. Although channels engineered with one Lys274 site carry just one SUMO1 they are activated and silenced by SENP1 and SUMO1 like wild-type channels. PMID:20498050

  8. Diffusing diffusivity: Rotational diffusion in two and three dimensions

    NASA Astrophysics Data System (ADS)

    Jain, Rohit; Sebastian, K. L.

    2017-06-01

    We consider the problem of calculating the probability distribution function (pdf) of angular displacement for rotational diffusion in a crowded, rearranging medium. We use the diffusing diffusivity model and following our previous work on translational diffusion [R. Jain and K. L. Sebastian, J. Phys. Chem. B 120, 3988 (2016)], we show that the problem can be reduced to that of calculating the survival probability of a particle undergoing Brownian motion, in the presence of a sink. We use the approach to calculate the pdf for the rotational motion in two and three dimensions. We also propose new dimensionless, time dependent parameters, αr o t ,2 D and αr o t ,3 D, which can be used to analyze the experimental/simulation data to find the extent of deviation from the normal behavior, i.e., constant diffusivity, and obtain explicit analytical expressions for them, within our model.

  9. Transitional structures of the TiO 2(110) surface from p(1×1) to p(1×2) studied by impact collision ion scattering spectroscopy

    NASA Astrophysics Data System (ADS)

    Asari, E.; Hayami, W.; Souda, R.

    2000-10-01

    The transitional states of surface structure of TiO 2(110) from p(1×1) to p(1×2) on low reduced to heavily reduced surfaces were studied using Impact Collision Ion Scattering Spectroscopy (ICISS). We found that (i) bridging oxygen rows were formed on low reduced surface at anneal temperature of 650°C for 2.5 h, (ii) Ti 2O unit rows were formed between the bridging oxygen rows on low reduced surface at anneal temperature of 930°C for 100 min, (iii) five-fold titanium atom rows on the surface and titanium atom rows of the Ti 2O rows are imperfectly covered with oxygen atoms on heavily reduced surface at anneal temperature of 600°C for 1 h and followed by 670°C annealing for 5 min after ion sputtering, and (iv) Ti 2O 3 unit rows proposed by Onishi and Iwasawa [H. Onishi and Y. Iwasawa, Surf. Sci. Lett., 313, 1994, L783] were completed by covering with oxygen atoms on all of the titanium atom rows on the Ti 2O rows on heavily reduced surface at higher anneal temperature of 1050°C for 40 min after ion sputtering. It is noticeable that the p(1×2) surface structures on low reduced surface is different from that of heavily reduced surface, viz., each has Ti 2O unit rows and Ti 2O 3 unit rows, respectively. The result contradicts "missing unit model" proposed by Bennett et al. [R.A. Bennett, P. Stone, N.J. Price, M. Bowker, Phys. Rev. Lett., 82, 1999, 3831].

  10. Asthmatic bronchial epithelium activated by the proteolytic allergen Der p 1 increases selective dendritic cell recruitment.

    PubMed

    Pichavant, Muriel; Charbonnier, Anne-Sophie; Taront, Solenne; Brichet, Anne; Wallaert, Benoît; Pestel, Joel; Tonnel, André-Bernard; Gosset, Philippe

    2005-04-01

    Airway dendritic cells (DCs) are crucial for allergen-induced sensitization and inflammation in allergic asthma. After allergen challenge, an increased number of DCs is observed in airway epithelium from patients with allergy. Because Der p 1, a cysteine protease allergen from Dermatophagoides pteronyssinus , induces chemokine production by bronchial epithelial cells (BECs), the purpose of this investigation was to evaluate the capacity of BEC exposed to Der p 1 to recruit DCs. Chemotactic activity of BEAS-2B, a bronchial epithelial cell line, and BECs from nonatopic controls and patients with allergic asthma was evaluated on the migration of precursors, immature and mature monocyte-derived DCs (MDDCs), and CD34 + -derived Langerhans cells (LCs). C-C chemokine ligand (CCL)-2, CCL5, and C-X-C chemokine ligand 10 production by BEAS-2B and BEC was increased after Der p 1 exposure, whereas the proenzyme proDer p 1 devoid of enzymatic activity had no effect. Der p 1 stimulation of BEAS-2B and BEC from both groups increased significantly the recruitment of MDDC precursors, depending on CCL2, CCL5, and C-X-C chemokine ligand 10 production. In a reconstituted polarized epithelium, apical application of Der p 1 enhanced MDDC precursor migration into the epithelial layer. Moreover, Der p 1 stimulation of BEC from patients with asthma but not from controls increased the migration of LC precursors, mainly dependent on CCL20 secretion. No migration of immature and mature DCs was observed. These data confirmed that BECs participate in the homeostasis of the DC network present within the bronchial epithelium through the secretion of chemokines. In allergic asthma, upregulation of CCL20 production induced LC recruitment, the role of which remains to be determined.

  11. Efficacy of Leishmania donovani ribosomal P1 gene as DNA vaccine in experimental visceral leishmaniasis.

    PubMed

    Masih, Shet; Arora, Sunil K; Vasishta, Rakesh K

    2011-09-01

    The acidic ribosomal proteins of the protozoan parasites have been described as prominent antigens during human disease. We present here data showing the molecular cloning and protective efficacy of P1 gene of Leishmania donovani as DNA vaccine. The PCR amplified complete ORF cloned in either pQE or pVAX vector was used either as peptide or DNA vaccine against experimentally induced visceral leishmaniasis in hamsters. The recombinant protein rLdP1 was given along with Freund's adjuvant and the plasmid DNA vaccine, pVAX-P1 was used alone either as single dose or double dose (prime and boost) in different groups of hamsters which were subsequently challenged with a virulent dose of 1×10(7) L. donovani (MHOM/IN/DD8/1968 strain) promastigotes by intra-cardiac route. While the recombinant protein rLdP1 or DNA vaccine pVAX-P1 in single dose format were not found to be protective, DNA vaccine in a prime-boost mode was able to induce protection with reduced mortality, a significant (75.68%) decrease in splenic parasite burden and increased expression of Th1 type cytokines in immunized hamsters. Histopathology of livers and spleens from these animals showed formation of mature granulomas with compact arrangement of lymphocytes and histiocytes, indicating its protective potential as vaccine candidate.

  12. Differential P1 arginine and lysine recognition in the prototypical proprotein convertase Kex2

    PubMed Central

    Wheatley, Joshua L.; Holyoak, Todd

    2007-01-01

    The high-resolution crystal structure of kexin (Kex2) in complex with a peptidyl-chloromethylketone inhibitor containing a noncognate lysine at the P1 position provides the structural basis for the differential lysine/arginine selectivity that defines the prohormone (proprotein) convertase (PC) family. By comparison with the previous structures of Kex2 and furin, this structure of the acylated enzyme provides a basis for the observed decrease in the acylation rate with substrates containing a lysine at P1 and the absence of an effect on the deacylation rate without involving mobility of the S1 lid. The structure of the complex shows that a secondary subsite in the S1 pocket is present, and that this site recognizes and binds the P1 lysine in a more shallow fashion than arginine. This results in a displacement of the bound peptide away from the S385 nucleophile relative to substrates containing a P1 arginine. It is concluded that this alternate binding site and resultant displacement of the scissile bond in the active site results in the observed decrease in the acylation rate. Studies of the inactivation kinetics of Kex2 by two peptidyl chloromethylketone inhibitors demonstrates that the selectivity between lysine and arginine at the P1 position arises at the acylation step, consistent with what was observed with peptidyl substrates [Rockwell NC, Fuller RS (2001) J Biol Chem 276:38394–38399]. PMID:17426142

  13. P1 interneurons promote a persistent internal state that enhances inter-male aggression in Drosophila

    PubMed Central

    Hoopfer, Eric D; Jung, Yonil; Inagaki, Hidehiko K; Rubin, Gerald M; Anderson, David J

    2015-01-01

    How brains are hardwired to produce aggressive behavior, and how aggression circuits are related to those that mediate courtship, is not well understood. A large-scale screen for aggression-promoting neurons in Drosophila identified several independent hits that enhanced both inter-male aggression and courtship. Genetic intersections revealed that 8-10 P1 interneurons, previously thought to exclusively control male courtship, were sufficient to promote fighting. Optogenetic experiments indicated that P1 activation could promote aggression at a threshold below that required for wing extension. P1 activation in the absence of wing extension triggered persistent aggression via an internal state that could endure for minutes. High-frequency P1 activation promoted wing extension and suppressed aggression during photostimulation, whereas aggression resumed and wing extension was inhibited following photostimulation offset. Thus, P1 neuron activation promotes a latent, internal state that facilitates aggression and courtship, and controls the overt expression of these social behaviors in a threshold-dependent, inverse manner. DOI: http://dx.doi.org/10.7554/eLife.11346.001 PMID:26714106

  14. Dust anchoring characteristics of electret fibres with respect to Der p 1 allergen carrying particles.

    PubMed

    Gaynor, P T; Hughes, J F

    1998-09-01

    The avoidance of house dust mite allergens is a major area of interest and essentially requires a significant removal of these allergens from the immediately respirable air. Electrostatic attraction and anchoring of particulate matter using electret polymers is commonly used for air filtration purposes. This effect is investigated for its possible use in domestic allergen avoidance. Polypropylene electret, heat-treated electret and non-electret, and wool and nylon fibre samples were soiled with house dust known to contain Der p 1 allergen. These samples were vacuumed at three air face velocities. The proportions of released and anchored dust were calculated. Released dust was collected and analysed for Der p 1 concentration and compared to stock dust values. Results showed that compared to uncharged fibres at least 95% more dust remained anchored in the electret fibres. Also, overall Der p 1 release was reduced by more than 49%. Der p 1 allergen concentrations in the collected dust were relatively constant for all the fibres tested, indicating no selective attraction or repulsion of Der p 1 allergen carrying particles in the experimental dust. The consistently high dust anchoring ability of the electret fibres could be used in many domestic products that are known to harbour particulate allergens, to reduce their release and inhalation.

  15. P1 Ref Endonuclease: A Molecular Mechanism for Phage-Enhanced Antibiotic Lethality

    PubMed Central

    Ronayne, Erin A.; Wan, Y. C. Serena; Boudreau, Beth A.; Landick, Robert; Cox, Michael M.

    2016-01-01

    Ref is an HNH superfamily endonuclease that only cleaves DNA to which RecA protein is bound. The enigmatic physiological function of this unusual enzyme is defined here. Lysogenization by bacteriophage P1 renders E. coli more sensitive to the DNA-damaging antibiotic ciprofloxacin, an example of a phenomenon termed phage-antibiotic synergy (PAS). The complementary effect of phage P1 is uniquely traced to the P1-encoded gene ref. Ref is a P1 function that amplifies the lytic cycle under conditions when the bacterial SOS response is induced due to DNA damage. The effect of Ref is multifaceted. DNA binding by Ref interferes with normal DNA metabolism, and the nuclease activity of Ref enhances genome degradation. Ref also inhibits cell division independently of the SOS response. Ref gene expression is toxic to E. coli in the absence of other P1 functions, both alone and in combination with antibiotics. The RecA proteins of human pathogens Neisseria gonorrhoeae and Staphylococcus aureus serve as cofactors for Ref-mediated DNA cleavage. Ref is especially toxic during the bacterial SOS response and the limited growth of stationary phase cultures, targeting aspects of bacterial physiology that are closely associated with the development of bacterial pathogen persistence. PMID:26765929

  16. STS-113 Astronauts Work on Port One (P1) Truss on International Space Station

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The 16th American assembly flight and 112th overall American flight to the International Space Station (ISS) launched on November 23, 2002 from Kennedy's launch pad 39A aboard the Space Shuttle Orbiter Endeavor STS-113. Mission objectives included the delivery of the Expedition Six Crew to the ISS, the return of Expedition Five crew back to Earth, and the installation and activation of the Port 1 Integrated Truss Assembly (P1). The first major component installed on the left side of the Station, the P1 truss provides an additional three External Thermal Control System radiators. Weighing in at 27,506 pounds, the P1 truss is 45 feet (13.7 meters) long, 15 feet (4.6 meters) wide, and 13 feet (4 meters) high. Three space walks, aided by the use of the Robotic Manipulator Systems of both the Shuttle and the Station, were performed in the installation of P1. In this photograph, astronauts Michael E. Lopez-Alegria (above) and John B. Herrington (below) work on the newly installed P1 truss during the mission's second scheduled session of extravehicular activity. The space walk lasted 6 hours, 10 minutes. The end effector of the Canadarm2 or Space Station Remote Manipulator System (SSRMS) and Earth's horizon are visible in the bottom of frame.

  17. FoxP1 orchestration of ASD-relevant signaling pathways in the striatum

    PubMed Central

    Araujo, Daniel J.; Anderson, Ashley G.; Berto, Stefano; Runnels, Wesley; Harper, Matthew; Ammanuel, Simon; Rieger, Michael A.; Huang, Hung-Chung; Rajkovich, Kacey; Loerwald, Kristofer W.; Dekker, Joseph D.; Tucker, Haley O.; Dougherty, Joseph D.; Gibson, Jay R.; Konopka, Genevieve

    2015-01-01

    Mutations in the transcription factor Forkhead box p1 (FOXP1) are causative for neurodevelopmental disorders such as autism. However, the function of FOXP1 within the brain remains largely uncharacterized. Here, we identify the gene expression program regulated by FoxP1 in both human neural cells and patient-relevant heterozygous Foxp1 mouse brains. We demonstrate a role for FoxP1 in the transcriptional regulation of autism-related pathways as well as genes involved in neuronal activity. We show that Foxp1 regulates the excitability of striatal medium spiny neurons and that reduction of Foxp1 correlates with defects in ultrasonic vocalizations. Finally, we demonstrate that FoxP1 has an evolutionarily conserved role in regulating pathways involved in striatal neuron identity through gene expression studies in human neural progenitors with altered FOXP1 levels. These data support an integral role for FoxP1 in regulating signaling pathways vulnerable in autism and the specific regulation of striatal pathways important for vocal communication. PMID:26494785

  18. DNA bending by the silencer protein NeP1 is modulated by TR and RXR.

    PubMed Central

    Arnold, R; Burcin, M; Kaiser, B; Muller, M; Renkawitz, R

    1996-01-01

    NeP1 binds to the F1 silencer element of the chicken lysozyme gene and, in the presence of TR, v-ERBA or RAR, synergistically represses transcriptional activity. This repression involves a silencing mechanism acting independently of the relative promoter position. Here we show that NeP1 alone can induce a significant directed bend on DNA. The chicken homologue of human NeP1, CTCF, shows identical binding and bending properties. In contrast, the isolated DNA binding domain of CTCF efficiently binds DNA, but fails to confer bending. Similarly, the TR-RXR hetero- or homodimer, binding adjacent to NeP1 at the F2 sequence, do not show significant DNA bending. The binding of the T3 ligand to TR changes neither the magnitude nor the direction of the NeP1 induced bend. However, when all factors are bound simultaneously as a quaternary complex, the TR-RXR heterodimer changes the location of the bend center, the flexure angle and the bending direction. PMID:8758989

  19. Microfabricated diffusion source

    DOEpatents

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  20. Visualization of bacteriophage P1 infection by cryo-electron tomography of tiny Escherichia coli

    SciTech Connect

    Liu Jun; Chen Chengyen; Shiomi, Daisuke; Niki, Hironori; Margolin, William

    2011-09-01

    Bacteriophage P1 has a contractile tail that targets the conserved lipopolysaccharide on the outer membrane surface of the host for initial adsorption. The mechanism by which P1 DNA enters the host cell is not well understood, mainly because the transient molecular interactions between bacteriophage and bacteria have been difficult to study by conventional approaches. Here, we engineered tiny E. coli host cells so that the initial stages of P1-host interactions could be captured in unprecedented detail by cryo-electron tomography. Analysis of three-dimensional reconstructions of frozen-hydrated specimens revealed three predominant configurations: an extended tail stage with DNA present in the phage head, a contracted tail stage with DNA, and a contracted tail stage without DNA. Comparative analysis of various conformations indicated that there is uniform penetration of the inner tail tube into the E. coli periplasm and a significant movement of the baseplate away from the outer membrane during tail contraction.

  1. BEAM EXTRACTION FROM THE RECYCLER RING TO P1 LINE AT FERMILAB

    SciTech Connect

    Xiao, M.; Capista, D.; Adams, P.; Morris, D.; Yang, M. J.; Hazewood, K.

    2016-10-03

    The transfer line for beam extraction from the Recycler ring to P1 line provides a way to deliver 8 GeV kinetic energy protons from the Booster to the Delivery ring, via the Recycler, using existing beam transport lines, and without the need for new civil construction. It was designed in 2012. The kicker magnets at RR520 and the lambertson magnet at RR522 in the RR were installed in 2014 Summer Shutdown, the elements of RR to P1 Stub (permanent quads, trim quads, correctors, BPMs, the toroid at 703 and vertical bending dipole at V703 (ADCW) were installed in 2015 Summer Shutdown. On Tuesday, June 21, 2016, beam line from the Recycler Ring to P1 line was commissioned. The detailed results will be presented in this report.

  2. P1 and N170 components distinguish human-like and animal-like makeup stimuli.

    PubMed

    Luo, Shuwei; Luo, Wenbo; He, Weiqi; Chen, Xu; Luo, Yuejia

    2013-06-19

    This study used event-related potentials to investigate the sensitivity of P1 and N170 components to human-like and animal-like makeup stimuli, which were derived from pictures of Peking opera characters. As predicted, human-like makeup stimuli elicited larger P1 and N170 amplitudes than did animal-like makeup stimuli. Interestingly, a right hemisphere advantage was observed for human-like but not for animal-like makeup stimuli. Dipole source analyses of 130-200-ms window showed that the bilateral fusiform face area may contribute to the differential sensitivity of the N170 component in response to human-like and animal-like makeup stimuli. The present study suggests that the amplitudes of both the P1 and the N170 are sensitive for the mouth component of face-like stimuli.

  3. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, is lowered into a work stand in the Operations and Checkout Building where it will undergo processing. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  4. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, is moved the length of the Operations and Checkout Building to its work stand where it will undergo processing. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  5. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Inside the Operations and Checkout Building, the P-1 truss, a component of the International Space Station, is lifted out of its canister to move to a work stand where it will undergo processing. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000- pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  6. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss (top of photo), a component of the International Space Station, nears its work stand in the Operations and Checkout Building where it will undergo processing. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by- 15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  7. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The P-1 truss, a component of the International Space Station, is moved the length of the Operations and Checkout Building to its work stand where it will undergo processing. Scheduled to fly in spring of 2002, the P-1 is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  8. Evoked alpha and early access to the knowledge system: the P1 inhibition timing hypothesis.

    PubMed

    Klimesch, Wolfgang

    2011-08-23

    In this article, a theory is presented which assumes that the visual P1 reflects the same cognitive and physiological functionality as alpha (with a frequency of about 10 Hz).Whereas alpha is an ongoing process, the P1 is the manifestation of an event-related process. It is suggested that alpha and the P1 reflect inhibition that is effective during early access to a complex knowledge system (KS). Most importantly, inhibition operates in two different ways. In potentially competing and task irrelevant networks, inhibition is used to block information processing. In task relevant neural networks, however, inhibition is used to increase the signal to noise ratio (SNR) by enabling precisely timed activity in neurons with a high level of excitation but silencing neurons with a comparatively low level of excitation. Inhibition is increased to modulate the SNR when processing complexity and network excitation increases and when certain types of attentional demands - such as top-down control, expectancy or reflexive attention - increase. A variety of findings are reviewed to demonstrate that they can well be interpreted on the basis of the suggested theory. One interesting aspect thereby is that attentional benefits (reflected e.g., by a larger P1 for attended as compared to unattended items at contralateral sites) and costs (reflected e.g., by a larger P1 at ipsilateral sites) can both be interpreted in terms of inhibition. In the former case an increased P1 is associated with a more effective processing of the presented item (due to an inhibition modulated increase in SNR), in the latter case, however, with a suppression of item processing (due to inhibition that blocks information processing). Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Serologic analysis of human rotavirus serotypes P1A and P2 by using monoclonal antibodies.

    PubMed Central

    Padilla-Noriega, L; Werner-Eckert, R; Mackow, E R; Gorziglia, M; Larralde, G; Taniguchi, K; Greenberg, H B

    1993-01-01

    Three human rotavirus (HRV) VP4 serotypes and one subtype have been described on the basis of a fourfold or an eightfold-or-greater difference in neutralization titer when tested with hyperimmune antisera to recombinant VP4 or VP8* (serotypes P1A, P1B, P2, and P3). To start to analyze the antigenic basis underlying serotype specificity, we produced a library of 13 VP4-specific neutralizing monoclonal antibodies (NMAbs) to two HRVs, the serotype P1A strain Wa and the serotype P2 strain ST3, and characterized the reactivity of these NMAbs with a panel of serotypically diverse HRV strains by neutralization assay and enzyme-linked immunosorbent assay (ELISA). We characterized the serotypic specificity of the NMAbs by using a fourfold or an eightfold-or-greater difference in titer against the homologous (i.e., immunogen) and heterologous strains as a criterion for serotype. Some ST3-derived NMAbs reacted specifically with serotype P2 HRVs by ELISA and/or neutralization assay, while some Wa-derived NMAbs reacted specifically by ELISA and/or neutralization assay with some or all serotype P1A HRVs. Other Wa- and ST3-derived NMAbs reacted with some or all serotype P1A and P2 HRV strains by neutralization assay and ELISA. Most NMAbs did not react with serotype P1B or P3 strains. In previous studies, three distinct operationally defined epitopes have been identified on VP4 by examining the reactivity patterns of selected antigenic variants of HRV strain KU. At least one of the NMAbs described here recognizes an epitope unrelated to these previously identified epitopes, since it neutralized both KU and its variants. Images PMID:7681440

  10. Bacterial Transition Metal P1B-ATPases, Transport Mechanism and Roles in Virulence

    PubMed Central

    Argüello, José M.; González-Guerrero, Manuel; Raimunda, Daniel

    2011-01-01

    P1B-type ATPases are polytopic membrane proteins that couple the hydrolysis of ATP to the efflux of cytoplasmic transition metals. This article reviews recent progress in our understanding of the structure and function of these proteins in bacteria. These are members of the P-type superfamily of transport ATPases. Cu+-ATPases are the most frequently observed and best-characterized members of this group of transporters. However, bacterial genomes show diverse arrays of P1B-type ATPases with a range of substrates (Cu+, Zn2+, Co2+). Furthermore, because of the structural similarities among transitions metals, these proteins can also transport non-physiological substrates (Cu2+, Cd2+, Pb2+, Au+, Ag+). P1B-type ATPases have six or eight transmembrane segments (TM) with metal coordinating amino acids in three core TMs flanking the cytoplasmic domain responsible for ATP binding and hydrolysis. In addition, regulatory cytoplasmic metal binding domains are present in most P1B-type ATPases. Central to the transport mechanism is the binding of the uncomplexed metal to these proteins when cytoplasmic substrates are bound to chaperone and chelating molecules. Metal binding to regulatory sites is through a reversible metal exchange among chaperones and cytoplasmic metal binding domains. In contrast, the chaperone-mediated metal delivery to transport sites appears as a largely irreversible event. P1B-ATPases have two overarching physiological functions: to maintain cytoplasmic metal levels and to provide metals for the periplasmic assembly of metalloproteins. Recent studies have shown that both roles are critical for bacterial virulence, since P1B-ATPases appear key to overcome high phagosomal metal levels and are required for the assembly of periplasmic and secreted metalloproteins that are essential for survival in extreme oxidant environments. PMID:21999638

  11. FoxP1 Protein Shows Differential Layer Expression in the Parahippocampal Domain among Bird Species.

    PubMed

    Garcia-Calero, Elena; Martinez, Salvador

    2016-01-01

    Different bird orders show diversity in neural capabilities supported by variations in brain morphology. The parahippocampal domain in the medial pallium, together with the hippocampus proper, plays an important role in memory skills. In the present work, we analyze the expression pattern of the FoxP1 protein in the parahippocampal area of four different bird species: the nonvocal learner birds quail and chicken (Galliformes) and two vocal learner birds, i.e. the zebra finch (Passeriformes) and the budgerigar (Psittaciformes), at different developmental and adult stages. We also analyze the expression of the calbindin protein in quails and zebra finches. We observed differences in the FoxP1 parahippocampal layer among bird species. In quails, chickens, and budgerigar, FoxP1 cells were located in the outer layers of the lateral and caudolateral parahippocampal sectors. In contrast, FoxP1 immunoreactive cells appeared in the inner layer of the same sectors in the zebra finch parahippocampal domain. These differences suggest two possibilities: either the FoxP1-positive cells described in quails, chickens, and budgerigars are a different population than the one described in the zebra finch, or there are changes in the pattern of radial migration in the parahippocampal area among birds. In the present study, we show that FoxP1 expression is more similar between quails, chickens, and budgerigars than between budgerigars and zebra finches in the parahippocampal area. This result contrasts with previous data in other telencephalic structures, like the calbindin-positive projection neurons described in the striatum of budgerigars and zebra finches but not in quails and chickens. All of these data point to diversity in the evolution of different morphological characters and, therefore, a mosaic model for telencephalic evolution in birds. © 2016 S. Karger AG, Basel.

  12. Evoked alpha and early access to the knowledge system: The P1 inhibition timing hypothesis☆

    PubMed Central

    Klimesch, Wolfgang

    2011-01-01

    In this article, a theory is presented which assumes that the visual P1 reflects the same cognitive and physiological functionality as alpha (with a frequency of about 10 Hz).Whereas alpha is an ongoing process, the P1 is the manifestation of an event-related process. It is suggested that alpha and the P1 reflect inhibition that is effective during early access to a complex knowledge system (KS). Most importantly, inhibition operates in two different ways. In potentially competing and task irrelevant networks, inhibition is used to block information processing. In task relevant neural networks, however, inhibition is used to increase the signal to noise ratio (SNR) by enabling precisely timed activity in neurons with a high level of excitation but silencing neurons with a comparatively low level of excitation. Inhibition is increased to modulate the SNR when processing complexity and network excitation increases and when certain types of attentional demands – such as top–down control, expectancy or reflexive attention – increase. A variety of findings are reviewed to demonstrate that they can well be interpreted on the basis of the suggested theory. One interesting aspect thereby is that attentional benefits (reflected e.g., by a larger P1 for attended as compared to unattended items at contralateral sites) and costs (reflected e.g., by a larger P1 at ipsilateral sites) can both be interpreted in terms of inhibition. In the former case an increased P1 is associated with a more effective processing of the presented item (due to an inhibition modulated increase in SNR), in the latter case, however, with a suppression of item processing (due to inhibition that blocks information processing). PMID:21774917

  13. Calculation of < p> and < p-1> from variational atomic electron densities

    NASA Astrophysics Data System (ADS)

    Glossman, M. Daniel; Castro, Eduardo A.

    1990-03-01

    Recently Pathak and Gadre discussed the relationship between the electron density ρ( r) and the expectation values < p> and < p-1>. In a previous work by the authors, the Thomas-Fermi-Dirac energy-density functional has been used to assess the effect of the modified Weizsäcker gradient expansion correction on ρ( r). In this paper, use is made of this electron density, and the effect of the gradient expansion correction on the expectation values < p> and < p-1> is assessed. Also the peak value of the Compton profile J(0) is calculated.

  14. ON DIFFERENTIABILITY OF FUNCTIONS IN L^p, 0 < p < 1

    NASA Astrophysics Data System (ADS)

    Krotov, V. G.

    1983-02-01

    In this paper the author studies the connection between smoothness, expressed in terms of the integral modulus of continuity, and the existence of a derivative, understood in some sense, for functions in L^p, 0 < p < 1; an analogous question is considered for boundary values of analytic functions in the Hardy classes H^p, 0 < p < 1. A connection is established between the derivatives of an analytic function in H^p and the derivatives of its boundary value; both global and pointwise derivatives are considered.Bibliography: 25 titles.

  15. SUMOylation silences heterodimeric TASK potassium channels containing K2P1 subunits in cerebellar granule neurons.

    PubMed

    Plant, Leigh D; Zuniga, Leandro; Araki, Dan; Marks, Jeremy D; Goldstein, Steve A N

    2012-11-20

    The standing outward K(+) current (IKso) governs the response of cerebellar granule neurons to natural and medicinal stimuli including volatile anesthetics. We showed that SUMOylation silenced half of IKso at the surface of cerebellar granule neurons because the underlying channels were heterodimeric assemblies of K2P1, a subunit subject to SUMOylation, and the TASK (two-P domain, acid-sensitive K(+)) channel subunits K2P3 or K2P9. The heterodimeric channels comprised the acid-sensitive portion of IKso and mediated its response to halothane. We anticipate that SUMOylation also influences sensation and homeostatic mechanisms in mammals through TASK channels formed with K2P1.

  16. Synthesis and P1' SAR exploration of potent macrocyclic tissue factor-factor VIIa inhibitors

    SciTech Connect

    Ladziata, Vladimir; Glunz, Peter W.; Zou, Yan; Zhang, Xiaojun; Jiang, Wen; Jacutin-Porte, Swanee; Cheney, Daniel L.; Wei, Anzhi; Luettgen, Joseph M.; Harper, Timothy M.; Wong, Pancras C.; Seiffert, Dietmar; Wexler, Ruth R.; Priestley, E. Scott

    2016-10-01

    Selective tissue factor-factor VIIa complex (TF-FVIIa) inhibitors are viewed as promising compounds for treating thrombotic disease. In this contribution, we describe multifaceted exploratory SAR studies of S1'-binding moieties within a macrocyclic chemotype aimed at replacing cyclopropyl sulfone P1' group. Over the course of the optimization efforts, the 1-(1H-tetrazol-5-yl)cyclopropane P1' substituent emerged as an improved alternative, offering increased metabolic stability and lower clearance, while maintaining excellent potency and selectivity.

  17. Diffusion bonding aeroengine components

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, G. A.; Broughton, T.

    1988-10-01

    The use of diffusion bonding processes at Rolls-Royce for the manufacture of titanium-alloy aircraft engine components and structures is described. A liquid-phase diffusion bonding process called activated diffusion bonding has been developed for the manufacture of the hollow titanium wide chord fan blade. In addition, solid-state diffusion bonding is being used in the manufacture of hollow vane/blade airfoil constructions mainly in conjunction with superplastic forming and hot forming techniques.

  18. Acoustic diffusers III

    NASA Astrophysics Data System (ADS)

    Bidondo, Alejandro

    2002-11-01

    This acoustic diffusion research presents a pragmatic view, based more on effects than causes and 15 very useful in the project advance control process, where the sound field's diffusion coefficient, sound field diffusivity (SFD), for its evaluation. Further research suggestions are presented to obtain an octave frequency resolution of the SFD for precise design or acoustical corrections.

  19. Reduce Confusion about Diffusion.

    ERIC Educational Resources Information Center

    Hebrank, Mary R.

    1997-01-01

    Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…

  20. A Student Diffusion Activity

    ERIC Educational Resources Information Center

    Kutzner, Mickey; Pearson, Bryan

    2017-01-01

    Diffusion is a truly interdisciplinary topic bridging all areas of STEM education. When biomolecules are not being moved through the body by fluid flow through the circulatory system or by molecular motors, diffusion is the primary mode of transport over short distances. The direction of the diffusive flow of particles is from high concentration…

  1. Diffusion of tungsten hexafluoride

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of tungsten hexafluoride

  2. Reduce Confusion about Diffusion.

    ERIC Educational Resources Information Center

    Hebrank, Mary R.

    1997-01-01

    Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…

  3. Handbook on atmospheric diffusion

    SciTech Connect

    Hanna, S.R.; Briggs, G.A.; Hosker, R.P. Jr.

    1982-01-01

    Basic meteorological concepts are covered as well as plume rise, source effects, and diffusion models. Chapters are included on cooling tower plumes and urban diffusion. Suggestions are given for calculating diffusion in special situations, such as for instantaneous releases over complex terrain, over long distances, and during times when chemical reactions or dry or wet deposition are important. (PSB)

  4. Diffusion Strategy Guide.

    ERIC Educational Resources Information Center

    McCutcheon, James R.; Sanders, John R.

    A methodology is presented for planning and managing the spread of educational innovations. The first portion of the guide develops a theoretical framework for diffusion which summarizes and capitalizes on the latest marketing and on the latest marketing and diffusion research findings. Major stages in the diffusion paradigm discussed include…

  5. Diffusion of uranium hexafluoride

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of uranium hexafluoride

  6. A Student Diffusion Activity

    NASA Astrophysics Data System (ADS)

    Kutzner, Mickey; Pearson, Bryan

    2017-02-01

    Diffusion is a truly interdisciplinary topic bridging all areas of STEM education. When biomolecules are not being moved through the body by fluid flow through the circulatory system or by molecular motors, diffusion is the primary mode of transport over short distances. The direction of the diffusive flow of particles is from high concentration toward low concentration.

  7. Local structural investigation of buried InAs(x)P(1-x)/InP interfaces

    NASA Astrophysics Data System (ADS)

    Lamberti, C.; Bordiga, S.; Boscherini, F.; Pascarelli, S.; Schiavini, G. M.; Ferari, C.; Lazzarini, L.; Salviati, G.

    1994-10-01

    A local structural investigation has been carried out on the 10 A InAs(x)P(1-x) layer in ad hoc grown InAs(x)P(1-x)/InP epitaxal multistructures deposited by low pressure metallorganic chemical vapor deposition by means of extended x-ray absorption fine structure spectroscopy, high resolution transmission electron microscopy, and high resolution x-ray diffraction analyses. The goal was to characterize the local structure of the unwanted, strained, interface layers of InAs(x)P(1-x) produced by the exposure of the InP surface to AsH3 as occurs during the growth of InP/In(0.53)Ga(0.47)As heterostructures optimized for photonics. High resolution x-ray diffraction and high resolution transmission electron microscopy confirm the high crystalline perfection of the investigated interfaces. As K-edge extended x-ray absorption fine structure analysis shows, the first shell environment of As at these interfaces is similar to that found in bulk InAs(x)P(1-X) alloys of similar composition, as determined experimentally and by comparison with recent theories of bond lengths in semiconductor alloys. In particular we measure an As-In bond length which varies at most 0.02 A with As concentration at the interface; this implies that epitaxy with InP is accompanied by local structural distortions, such as bond angle variations, which accommodate the nearly constant As-In bond length.

  8. Variability in P1 gene redefines phylogenetic relationships among cassava brown streak viruses.

    PubMed

    Mbewe, Willard; Tairo, Fred; Sseruwagi, Peter; Ndunguru, Joseph; Duffy, Siobain; Mukasa, Ssetumba; Benesi, Ibrahim; Sheat, Samar; Koerbler, Marianne; Winter, Stephan

    2017-06-20

    Cassava brown streak disease is emerging as the most important viral disease of cassava in Africa, and is consequently a threat to food security. Two distinct species of the genus Ipomovirus (family Potyviridae) cause the disease: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). To understand the evolutionary relationships among the viruses, 64 nucleotide sequences from the variable P1 gene from major cassava producing areas of east and central-southern Africa were determined. We sequenced an amplicon of the P1 region of 31 isolates from Malawi and Tanzania. In addition to these, 33 previously reported sequences of virus isolates from Uganda, Kenya, Tanzania, Malawi and Mozambique were added to the analysis. Phylogenetic analyses revealed three major P1 clades of Cassava brown streak viruses (CBSVs): in addition to a clade of most CBSV and a clade containing all UCBSV, a novel, intermediate clade of CBSV isolates which has been tentatively called CBSV-Tanzania (CBSV-TZ). Virus isolates of the distinctive CBSV-TZ had nucleotide identities as low as 63.2 and 63.7% with other members of CBSV and UCBSV respectively. Grouping of P1 gene sequences indicated for distinct sub-populations of CBSV, but not UCBSV. Representatives of all three clades were found in both Tanzania and Malawi.

  9. Airborne study of grass allergen (Lol p 1) in different-sized particles.

    PubMed

    De Linares, C; Díaz de la Guardia, C; Nieto Lugilde, D; Alba, F

    2010-01-01

    The Poaceae family is considered one of the main causes of pollen allergy in industrialized countries. The aim of this study is to establish the dynamics of the Poaceae allergens and determine their distribution in the different-sized particles in the atmosphere. The air of Granada (southern Spain) was sampled during the pollination period of Poaceae using a cascade impactor and a Hirst-type volumetric collector simultaneously. The sampled airborne allergens were analyzed by indirect ELISA and field emission scanning electron microscopy. Airborne pollen was evaluated with the Spanish Aerobiological Network methodology. Poaceae pollen and allergenic activity have parallel dynamics during the period of maximum pollination, which is reflected in the positive correlations between the 2 variables. In addition, the highest Lol p 1 concentrations were recorded in particle sizes lower than 3.3 mum (stage 4-F). The Spearman correlation test showed that airborne allergens are not dependent on meteorological factors, such as humidity, wind direction or sunshine, however, Lol p 1 allergen correlated positively with Poaceae pollen. The results of the present study confirm that the Lol p 1 allergen is detected more frequently with pollutants than with coarse particles with similar dynamics and a positive correlation between airborne pollen and aeroallergens. Moreover, Lol p 1 is released in stable weather conditions without large changes in humidity or temperature. Copyright 2009 S. Karger AG, Basel.

  10. Complete Genome Sequence of Rhodococcus sp. Strain IcdP1 Shows Diverse Catabolic Potential

    PubMed Central

    Qu, Jie; Miao, Li-Li; Liu, Ying

    2015-01-01

    The complete genome sequence of Rhodococcus sp. strain IcdP1 is presented here. This organism was shown to degrade a broad range of high-molecular-weight polycyclic aromatic hydrocarbons and organochlorine pesticides. The sequence data can be used to predict genes for xenobiotic biodegradation and metabolism. PMID:26139718

  11. Posterior P1 and early frontal negativity reflect developmental changes in attentional distraction during adolescence.

    PubMed

    Zhang, Wenhai; Li, Hong; Chen, Jie; Chen, Ning; Liu, Xia; Wang, Dahua; Shen, Jiliang

    2014-06-01

    Previous studies in adults have revealed that attentional distraction modulates the late positive potential (LPP) during emotion regulation. To determine whether early visual components reflect developmental changes in attentional distraction during adolescence, we collected event-related potentials from 20 young adolescents, 18 older adolescents, and 18 young adults as they performed a distraction task (counting) while viewing affective images. Consistent with previous findings obtained in distraction studies, the distraction task (counting) reduced emotional modulation of the LPP. At an early stage of processing, counting reduced emotional modulation of P1 and increased the negativity bias of early frontal negativity (eFN) for negatively valenced pictures compared to simple viewing with no distraction. sLORETA analyses further revealed eFN indexing of rostral prefrontal cortical activation, a cortical area that has been shown in recent fMRI studies to be activated by distraction. Moreover, P1 amplitudes in young and older adolescents did not differ but were both larger than the P1s in young adults. In addition, eFN amplitudes significantly decreased with age. The dissociable distraction patterns between the posterior P1 and eFN provide evidence not only for the timing hypothesis of emotion regulation but also for different developmental trajectories of visual processing areas and the prefrontal cortex during affective processing in adolescence. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion

    PubMed Central

    Liang, Rong; Ohnesorg, Thomas; Cho, Vicky; Abhayaratna, Walter P.; Gatenby, Paul A.; Perera, Chandima; Zhang, Yafei; Whittle, Belinda; Sinclair, Andrew; Goodnow, Christopher C.; Field, Matthew; Andrews, T. Daniel; Cook, Matthew C.

    2016-01-01

    Most humans harbor both CD177neg and CD177pos neutrophils but 1–10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1), which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation. PMID:27227454

  13. 26 CFR 31.3306(p)-1 - Employees of related corporations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Employees of related corporations. 31.3306(p)-1... of related corporations. (a) In general. For purposes of sections 3301, 3302, and 3306(b)(1), when two or more related corporations concurrently employ the same individual and compensate...

  14. Novel Mycosin Protease MycP1 Inhibitors Identified by Virtual Screening and 4D Fingerprints

    PubMed Central

    2015-01-01

    The rise of drug-resistant Mycobacterium tuberculosis lends urgency to the need for new drugs for the treatment of tuberculosis (TB). The identification of a serine protease, mycosin protease-1 (MycP1), as the crucial agent in hydrolyzing the virulence factor, ESX-secretion-associated protein B (EspB), potentially opens the door to new tuberculosis treatment options. Using the crystal structure of mycobacterial MycP1 in the apo form, we performed an iterative ligand- and structure-based virtual screening (VS) strategy to identify novel, nonpeptide, small-molecule inhibitors against MycP1 protease. Screening of ∼485 000 ligands from databases at the Genomics Research Institute (GRI) at the University of Cincinnati and the National Cancer Institute (NCI) using our VS approach, which integrated a pharmacophore model and consensus molecular shape patterns of active ligands (4D fingerprints), identified 81 putative inhibitors, and in vitro testing subsequently confirmed two of them as active inhibitors. Thereafter, the lead structures of each VS round were used to generate a new 4D fingerprint that enabled virtual rescreening of the chemical libraries. Finally, the iterative process identified a number of diverse scaffolds as lead compounds that were tested and found to have micromolar IC50 values against the MycP1 target. This study validated the efficiency of the SABRE 4D fingerprints as a means of identifying novel lead compounds in each screening round of the databases. Together, these results underscored the value of using a combination of in silico iterative ligand- and structure-based virtual screening of chemical libraries with experimental validation for the identification of promising structural scaffolds, such as the MycP1 inhibitors. PMID:24628123

  15. The lytic replicon of bacteriophage P1 is controlled by an antisense RNA.

    PubMed Central

    Heinrich, J; Riedel, H D; Rückert, B; Lurz, R; Schuster, H

    1995-01-01

    The lytic replicon of phage P1 is used for DNA replication during the lytic cycle. It comprises about 2% of the P1 genome and contains the P1 C1 repressor-controlled operator-promoter element Op53.P53 and the kilA and the repL genes, in that order. Transcription of the lytic replicon of P53 and synthesis of the product of repL, but not kilA, are required for replicon function. We have identified an additional promoter, termed P53as (antisense), at the 5'-end of the kilA gene from which a 180 base transcript is constitutively synthesized and in the opposite direction to the P53 transcript. By using a promoter probe plasmid we show that transcription from P53 is strongly repressed by the C1 repressor, whereas that of P53as remains unaffected. Accordingly, the C1 repressor inhibits binding of Escherichia coli RNA polymerase to P53, but not to P53as, as shown by electron microscopy. Under non-repressed conditions transcription from P53 appears to be inhibited by P53as activity and vice versa. An inhibitory effect of P53as on the P1 lytic replicon was revealed by the construction and characterization of a P53as promoter-down mutant. Under non-repressed conditions transcription of repL and, as a consequence, replication of the plasmid is strongly enhanced when P53as is inactive. The results suggest a regulatory role for P53as on the P1 lytic replicon. Images PMID:7784198

  16. Characterization of a Cobalt-Specific P1B-ATPase†

    PubMed Central

    Zielazinski, Eliza L.; Cutsail, George E.; Hoffman, Brian M.; Stemmler, Timothy L.; Rosenzweig, Amy C.

    2012-01-01

    The P1B-type ATPases are a ubiquitous family of P-type ATPases involved in the transport of transition metal ions. Divided into subclasses on the basis of sequence characteristics and substrate specificity, these integral membrane transporters play key roles in metal homeostasis, metal tolerance, and the biosynthesis of metalloproteins. The P1B-4-ATPases have the simplest architecture of the five P1B-ATPase families and have been suggested to play a role in Co2+ transport. A P1B-4-ATPase from Sulfitobacter sp. NAS-14.1, designated sCoaT, has been cloned, expressed, and purified. Activity assays indicate that sCoaT is specific for Co2+. A single Co2+ binding site is present, and optical, electron paramagnetic resonance (EPR), and X-ray absorption (XAS) spectroscopic data are consistent with tetrahedral coordination by oxygen and nitrogen ligands, including a histidine and likely a water. Surprisingly, there is no evidence for coordination by sulfur. Mutation of a conserved cysteine residue, Cys 327, in the signature transmembrane SPC metal binding motif does not abolish ATP hydrolysis activity or affect the spectroscopic analysis, establishing that this residue is not involved in the initial Co2+ binding by sCoaT. In contrast, replacements of conserved transmembrane residues Ser 325, His 657, Glu 658, and Thr 661 with alanine abolish ATP hydrolysis activity and Co2+ binding, indicating that these residues are necessary for Co2+ transport. These data represent the first in vitro characterization of a P1B-4-ATPase and its Co2+ binding site. PMID:22971227

  17. P1 Nonconforming Finite Element Method for the Solution of Radiation Transport Problems

    NASA Technical Reports Server (NTRS)

    Kang, Kab S.

    2002-01-01

    The simulation of radiation transport in the optically thick flux-limited diffusion regime has been identified as one of the most time-consuming tasks within large simulation codes. Due to multimaterial complex geometry, the radiation transport system must often be solved on unstructured grids. In this paper, we investigate the behavior and the benefits of the unstructured P(sub 1) nonconforming finite element method, which has proven to be flexible and effective on related transport problems, in solving unsteady implicit nonlinear radiation diffusion problems using Newton and Picard linearization methods. Key words. nonconforrning finite elements, radiation transport, inexact Newton linearization, multigrid preconditioning

  18. Structure and electronic properties of Zn-tetra-phenyl-porphyrin single- and multi-layers films grown on Fe(001)-p(1 × 1)O

    NASA Astrophysics Data System (ADS)

    Bussetti, Gianlorenzo; Calloni, Alberto; Celeri, Matteo; Yivlialin, Rossella; Finazzi, Marco; Bottegoni, Federico; Duò, Lamberto; Ciccacci, Franco

    2016-12-01

    The structure and the electronic properties of thin (1 molecular layer) and thick (20 molecular layers) Zn-tetra-phenyl-porphyrin (ZnTPP) films grown on a single metal oxide (MO) layer, namely Fe(001)-p(1 × 1)O, are shown and discussed. During the first stages of deposition, the ultra-thin MO layer reduces the molecule-substrate interaction enhancing the molecular diffusivity with the respect to other investigated substrates [namely, Si(111), Au(001) and oxygen-free Fe(001)]. On Fe(001)-p(1 × 1)O, ZnTPP molecules form an ordered and stable square-lattice array. The photoemission analysis of the valence bands reveals that all the characteristic features of the molecule are already visible in the 1 monolayer-thick sample spectrum. Similarly, the core level investigation suggests a weak molecule perturbation. The ZnTPP/Fe(001)-p(1 × 1)O interface represents a prototypical system to investigate the organic film adhesion on ultra-thin MO layers and the processes involved during the film growth.

  19. Pullback attractors for nonclassical diffusion equations with delays

    NASA Astrophysics Data System (ADS)

    Zhu, Kaixuan; Sun, Chunyou

    2015-09-01

    In this paper, we prove the existence of pullback attractors in C H0 1 ( Ω ) for a nonclassical diffusion equation with delay term g(t, ut) which contains some hereditary characteristics. We consider two types of nonlinearity f: one is the case of critical growth and the other one is the polynomial growth of arbitrary order p - 1(p ≥ 2).

  20. 26 CFR 1.409(p)-1T - Prohibited allocations of securities in an S corporation (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... corporation (temporary). 1.409(p)-1T Section 1.409(p)-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT..., Stock Bonus Plans, Etc. § 1.409(p)-1T Prohibited allocations of securities in an S corporation (temporary). (a) Organization of this section. Section 409(p) applies if a nonallocation year occurs in...

  1. 26 CFR 1.409(p)-1T - Prohibited allocations of securities in an S corporation (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... corporation (temporary). 1.409(p)-1T Section 1.409(p)-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT..., Stock Bonus Plans, Etc. § 1.409(p)-1T Prohibited allocations of securities in an S corporation (temporary). (a) Organization of this section. Section 409(p) applies if a nonallocation year occurs in...

  2. Phylogeny of replication initiator protein TrfA reveals a highly divergent clade of incompatibility group P1 plasmids

    USDA-ARS?s Scientific Manuscript database

    Incompatibility group P-1 (incP-1) includes broad host range plasmids of Gram negative bacteria and are classified into five subgroups (alpha, beta, gamma, delta, and epsilon). The incP-1 replication module consists of the trfA gene, encoding the replication initiator protein TrfA, and the origin o...

  3. Product Plan of New Generation System Camera "OLYMPUS PEN E-P1"

    NASA Astrophysics Data System (ADS)

    Ogawa, Haruo

    "OLYMPUS PEN E-P1", which is new generation system camera, is the first product of Olympus which is new standard "Micro Four-thirds System" for high-resolution mirror-less cameras. It continues good sales by the concept of "small and stylish design, easy operation and SLR image quality" since release on July 3, 2009. On the other hand, the half-size film camera "OLYMPUS PEN" was popular by the concept "small and stylish design and original mechanism" since the first product in 1959 and recorded sale number more than 17 million with 17 models. By the 50th anniversary topic and emotional value of the Olympus pen, Olympus pen E-P1 became big sales. I would like to explain the way of thinking of the product plan that included not only the simple functional value but also emotional value on planning the first product of "Micro Four-thirds System".

  4. Development of Quasi-3DOF upper limb rehabilitation system using ER brake: PLEMO-P1

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.; Fukushima, K.; Furusho, J.; Ozawa, T.

    2009-02-01

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. However, almost all the devices are active-type (motor-driven) haptic devices and they basically require high-cost safety system compared to passive-type (brake-based) devices. In this study, we developed a new practical haptic device 'PLEMO-P1'; this system adopted ER brakes as its force generators. In this paper, the mechanism of PLEMO-P1 and its software for a reaching rehabilitation are described.

  5. Effect of gradient expansion corrections on the expectation values

    and <p-1>

    NASA Astrophysics Data System (ADS)

    Csavinszky, P.

    1984-06-01

    Recently Pathak and Gadre discussed the relationship between the electron density ρ(r) and the expectation values and <p-1>. In previous work by the author, using the Na atom as an example, the Thomas-Fermi-Dirac energy-density functional has been used to assess the effect of the (modified) Weizsäcker, and the combined effect of the (modified) Weizsäcker and Hodges gradient expansion corrections on ρ(r). In this paper use is made of the respective electron densities, and the effect of the gradient expansion corrections on the expectation values and <p-1> is assessed. It is found that the effect of the (modified) Weizsäcker correction is significant, while the effect of the Hodges correction is more modest.

  6. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Inside the Operations and Checkout Building, an overhead crane lifts the top of the canister containing the P-1 truss, a component of the International Space Station. The truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by- 15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  7. Geohydrologic data for test well UE-25p1, Yucca Mountain area, Nye County, Nevada

    USGS Publications Warehouse

    Craig, R.W.; Johnson, K.A.

    1984-01-01

    This report presents the following data for test well UE-25p 1 in Nye County, Nevada: drilling operations, lithology, availability of borehole geophysical logs, water levels, future availability of core analyses, water chemistry, pumping tests, borehole-flow surveys, and packer-injection tests. The well is one of a series of test wells drilled in and near Yucca Mountain adjacent to the Nevada Test Site in cooperation with the U.S. Department of Energy. These investigations are part of the Nevada Nuclear Waste Storage Investigations to identify suitable sites for underground storage of high-level radioactive wastes. Test well UE-25p 1 was the first in the Yucca Mountain area to penetrate rocks of Paleozoic age. To a depth of 1,244 meters, the rocks are predominantly ash-flow tuffs of Tertiary age. From 1,244 meters to a total depth of 1,805 meters, the rock is dolomite of Paleozoic age. (USGS)

  8. A Tobacco Etch Virus Protease with Increased Substrate Tolerance at the P1' position

    PubMed Central

    Renicke, Christian; Spadaccini, Roberta; Taxis, Christof

    2013-01-01

    Site-specific proteases are important tools for in vitro and in vivo cleavage of proteins. They are widely used for diverse applications, like protein purification, assessment of protein–protein interactions or regulation of protein localization, abundance or activity. Here, we report the development of a procedure to select protease variants with altered specificity based on the well-established Saccharomyces cerevisiae adenine auxotrophy-dependent red/white colony assay. We applied this method on the tobacco etch virus (TEV) protease to obtain a protease variant with altered substrate specificity at the P1’ Position. In vivo experiments with tester substrates showed that the mutated TEV protease still efficiently recognizes the sequence ENLYFQ, but has almost lost all bias for the amino acid at the P1’ Position. Thus, we generated a site-specific protease for synthetic approaches requiring in vivo generation of proteins or peptides with a specific N-terminal amino acid. PMID:23826349

  9. P-1 truss moved to work stand in O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Inside the Operations and Checkout Building, an overhead crane lifts the top of the canister containing the P-1 truss, a component of the International Space Station. The truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure on the Station that will ultimately extend the length of a football field. Astronauts will attach the 14-by- 15 foot structure to the port side of the center truss, S0, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the Station's radiators away from the sun to increase their maximum cooling efficiency.

  10. Sumoylation Silences Heterodimeric TASK Potassium Channels Containing K2P1 Subunits in Cerebellar Granule Neurons

    PubMed Central

    Plant, Leigh D.; Zuniga, Leandro; Araki, Dan; Marks, Jeremy D.; Goldstein, Steve A. N.

    2013-01-01

    The standing outward K+ current (IKso) governs the response of cerebellar granule neurons to natural and medicinal stimuli including volatile anesthetics. In this study, we showed that sumoylation silenced half of IKso at the surface of cerebellar granule neurons because the underlying channels were heterodimeric assemblies of K2P1, a subunit subject to sumoylation, and the two P domain, acid-sensitive K+ (TASK) channel subunits, K2P3 or K2P9. The heteromeric channels comprised the acid-sensitive portion of IKso and mediated its response to halothane. We anticipate that sumoylation also influences sensation and homeostatic mechanisms in mammals through TASK channels formed with K2P1. PMID:23169818

  11. Prestimulus amplitudes modulate P1 latencies and evoked traveling alpha waves

    PubMed Central

    Himmelstoss, Nicole A.; Brötzner, Christina P.; Zauner, Andrea; Kerschbaum, Hubert H.; Gruber, Walter; Lechinger, Julia; Klimesch, Wolfgang

    2015-01-01

    Traveling waves have been well documented in the ongoing, and more recently also in the evoked EEG. In the present study we investigate what kind of physiological process might be responsible for inducing an evoked traveling wave. We used a semantic judgment task which already proved useful to study evoked traveling alpha waves that coincide with the appearance of the P1 component. We found that the P1 latency of the leading electrode is significantly correlated with prestimulus amplitude size and that this event is associated with a transient change in alpha frequency. We assume that cortical background excitability, as reflected by an increase in prestimulus amplitude, is responsible for the observed change in alpha frequency and the initiation of an evoked traveling trajectory. PMID:26074804

  12. A tobacco etch virus protease with increased substrate tolerance at the P1' position.

    PubMed

    Renicke, Christian; Spadaccini, Roberta; Taxis, Christof

    2013-01-01

    Site-specific proteases are important tools for in vitro and in vivo cleavage of proteins. They are widely used for diverse applications, like protein purification, assessment of protein-protein interactions or regulation of protein localization, abundance or activity. Here, we report the development of a procedure to select protease variants with altered specificity based on the well-established Saccharomyces cerevisiae adenine auxotrophy-dependent red/white colony assay. We applied this method on the tobacco etch virus (TEV) protease to obtain a protease variant with altered substrate specificity at the P1' Position. In vivo experiments with tester substrates showed that the mutated TEV protease still efficiently recognizes the sequence ENLYFQ, but has almost lost all bias for the amino acid at the P1' Position. Thus, we generated a site-specific protease for synthetic approaches requiring in vivo generation of proteins or peptides with a specific N-terminal amino acid.

  13. SPC-P1: a pathogenicity-associated prophage of Salmonella paratyphi C.

    PubMed

    Zou, Qing-Hua; Li, Qing-Hai; Zhu, Hong-Yun; Feng, Ye; Li, Yong-Guo; Johnston, Randal N; Liu, Gui-Rong; Liu, Shu-Lin

    2010-12-30

    Salmonella paratyphi C is one of the few human-adapted pathogens along with S. typhi, S. paratyphi A and S. paratyphi B that cause typhoid, but it is not clear whether these bacteria cause the disease by the same or different pathogenic mechanisms. Notably, these typhoid agents have distinct sets of large genomic insertions, which may encode different pathogenicity factors. Previously we identified a novel prophage, SPC-P1, in S. paratyphi C RKS4594 and wondered whether it might be involved in pathogenicity of the bacteria. We analyzed the sequence of SPC-P1 and found that it is an inducible phage with an overall G+C content of 47.24%, similar to that of most Salmonella phages such as P22 and ST64T but significantly lower than the 52.16% average of the RKS4594 chromosome. Electron microscopy showed short-tailed phage particles very similar to the lambdoid phage CUS-3. To evaluate its roles in pathogenicity, we lysogenized S. paratyphi C strain CN13/87, which did not have this prophage, and infected mice with the lysogenized CN13/87. Compared to the phage-free wild type CN13/87, the lysogenized CN13/87 exhibited significantly increased virulence and caused multi-organ damages in mice at considerably lower infection doses. SPC-P1 contributes pathogenicity to S. paratyphi C in animal infection models, so it is possible that this prophage is involved in typhoid pathogenesis in humans. Genetic and functional analyses of SPC-P1 may facilitate the study of pathogenic evolution of the extant typhoid agents, providing particular help in elucidating the pathogenic determinants of the typhoid agents.

  14. SPC-P1: a pathogenicity-associated prophage of Salmonella paratyphi C

    PubMed Central

    2010-01-01

    Background Salmonella paratyphi C is one of the few human-adapted pathogens along with S. typhi, S. paratyphi A and S. paratyphi B that cause typhoid, but it is not clear whether these bacteria cause the disease by the same or different pathogenic mechanisms. Notably, these typhoid agents have distinct sets of large genomic insertions, which may encode different pathogenicity factors. Previously we identified a novel prophage, SPC-P1, in S. paratyphi C RKS4594 and wondered whether it might be involved in pathogenicity of the bacteria. Results We analyzed the sequence of SPC-P1 and found that it is an inducible phage with an overall G+C content of 47.24%, similar to that of most Salmonella phages such as P22 and ST64T but significantly lower than the 52.16% average of the RKS4594 chromosome. Electron microscopy showed short-tailed phage particles very similar to the lambdoid phage CUS-3. To evaluate its roles in pathogenicity, we lysogenized S. paratyphi C strain CN13/87, which did not have this prophage, and infected mice with the lysogenized CN13/87. Compared to the phage-free wild type CN13/87, the lysogenized CN13/87 exhibited significantly increased virulence and caused multi-organ damages in mice at considerably lower infection doses. Conclusions SPC-P1 contributes pathogenicity to S. paratyphi C in animal infection models, so it is possible that this prophage is involved in typhoid pathogenesis in humans. Genetic and functional analyses of SPC-P1 may facilitate the study of pathogenic evolution of the extant typhoid agents, providing particular help in elucidating the pathogenic determinants of the typhoid agents. PMID:21192789

  15. 8-Methoxypsoralen is a competitive inhibitor of glutathione S-transferase P1-1

    PubMed Central

    de Oliveira, Diêgo Madureira; de Farias, Marcel Tavares; Teles, André Lacerda Braga; dos Santos Junior, Manoelito Coelho; de Cerqueira, Martins Dias; Lima, Rute Maria Ferreira; El-Bachá, Ramon Santos

    2014-01-01

    The blood-brain barrier (BBB) is known to protect healthy brain cells from potentially dangerous chemical agents, but there are many evidences supporting the idea that this protective action is extended to tumor cells. Since the process of angiogenesis in brain tumors leads to BBB breakdown, biochemical characteristics of the BBB seem to be more relevant than physical barriers to protect tumor cells from chemotherapy. In fact, a number of resistance related factors were already demonstrated to be component of both BBB and tumor cells. The enzyme glutathione S-transferases (GST) detoxify electrophilic xenobiotics and endogenous secondary metabolites formed during oxidative stress. A role has been attributed to GST in the resistance of cancer cells to chemotherapeutic agents. This study characterized 8-methoxypsoralen (8-MOP) as a human GST P1-1 (hGST P1-1) inhibitor. To identify and characterize the potential inhibitory activity of 8-MOP, we studied the enzyme kinetics of the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) with GSH catalyzed by hGST P1-1. We report here that 8-MOP competitively inhibited hGST P1-1 relative to CDNB, but there was an uncompetitive inhibition relative to GSH. Chromatographic analyses suggest that 8-MOP is not a substrate. Molecular docking simulations suggest that 8-MOP binds to the active site, but its position prevents the GSH conjugation. Thus, we conclude that 8-MOP is a promising prototype for new GST inhibitors pharmacologically useful in the treatment of neurodegenerative disorders and the resistance of cancer to chemotherapy. PMID:25324722

  16. Lamb shift in the hydrogen atom: Lifetime of the 2p{1/2}level

    SciTech Connect

    Karshenboim, S.G.

    1995-05-01

    Corrections of order {alpha}(Z{alpha}){sup 2} to the width of the 2p{1/2} level in the hydrogen atom are considered in the logarithmic approximation. The ratio of this width to the splitting of n=2 states can be measured to high accuracy. With the aid of the experimental data available for this ratio, the new value for the Lamb splitting is found to be 1057.8576(21) MHz. 17 refs.

  17. Slow-binding inhibitors of prolyl oligopeptidase with different functional groups at the P1 site.

    PubMed

    Venäläinen, Jarkko I; Juvonen, Risto O; Garcia-Horsman, J Arturo; Wallén, Erik A A; Christiaans, Johannes A M; Jarho, Elina M; Gynther, Jukka; Männistö, Pekka T

    2004-09-15

    POP (prolyl oligopeptidase) specifically hydrolyses a number of small proline-containing peptides at the carboxy end of the proline residue and POP inhibitors have been shown to have cognition-enhancing properties. It has been noted that certain functional groups at the P1 site of the inhibitor, which correspond to the substrate residue on the N-terminal side of the bond to be cleaved, increase the inhibitory potency. However, detailed mechanistic and kinetic analysis of the inhibition has not been studied. In the present study, we examined the effect of different functional groups at the P1 site of the parent inhibitor isophthalic acid bis-(L-prolylpyrrolidine) amide on the binding kinetics to POP. Addition of CHO, CN or COCH(2)OH groups to the P1 site increased the inhibitory potency by two orders of magnitude (K(i)=11.8-0.1 nM) and caused a clear slow-binding inhibition. The inhibitor containing a CHO group had the lowest association rate constant, k(on)=(2.43+/-0.12) x 10(5) M(-1) x s(-1), whereas the inhibitor with a CN group exhibited the fastest binding, k(on)=(12.0+/-0.08)x10(5) M(-1) x s(-1). In addition, the dissociation rate was found to be crucially dependent on the type of the functional group. Compounds with COCH(2)OH and CHO groups had much longer half-lives of dissociation (over 5 h) compared with the compound with the CN group (25 min), although the K(i) values of the compounds were relatively similar. A possibility to optimize the duration of inhibition by changing the functional group at the P1 site is important when planning therapeutically useful POP inhibitors.

  18. Expression of Dual-Specificity Phosphatase 5 Pseudogene 1 (DUSP5P1) in Tumor Cells

    PubMed Central

    Staege, Martin S.; Müller, Katja; Kewitz, Stefanie; Volkmer, Ines; Mauz-Körholz, Christine; Bernig, Toralf; Körholz, Dieter

    2014-01-01

    Sequencing of individual clones from a newly established cDNA library from the chemoresistant Hodgkin's lymphoma cell line L-1236 led to the isolation of a cDNA clone corresponding to a short sequence from chromosome 1. Reverse transcriptase-polymerase chain reaction indicated high expression of this sequence in Hodgkin's lymphoma derived cell lines but not in normal blood cells. Further characterization of this sequence and the surrounding genomic DNA revealed that this sequence is part of a human endogenous retrovirus locus. The sequence of this endogenous retrovirus is interrupted by a pseudogene of the dual specificity phosphatase 5 (DUSP5). Reverse transcriptase-polymerase chain reaction revealed high expression of this pseudogene (DUSP5P1) in HL cell lines but not in normal blood cells or Epstein-Barr virus-immortalized B cells. Cells from other tumor types (Burkitt's lymphoma, leukemia, neuroblastoma, Ewing sarcoma) also showed a higher DUSP5P1/DUSP5 ratio than normal cells. Furthermore, we observed that higher expression of DUSP5 in relation to DUSP5P1 correlated with the expression of the pro-apoptotic factor B cell leukemia/lymphoma 2-like 11 (BCL2L11) in peripheral blood cells and HL cells. Knock-down of DUSP5 in HL cells resulted in down-regulation of BCL2L11. Thus, the DUSP5/DUSP5P1 system could be responsible for regulation of BCL2L11 leading to inhibition of apoptosis in these tumor cells. PMID:24651368

  19. Pyrolysis products from amino acids and protein: highest mutagenicity requires cytochrome P1-450.

    PubMed

    Nebert, D W; Bigelow, S W; Okey, A B; Yahagi, T; Mori, Y; Nagao, M; Sugimura, T

    1979-11-01

    Pyrolysis products of proteins and amino acids are highly mutagenic, but metabolism of these chemicals by rat liver subcellular fractions is known to be required for production of the mutagenic intermediates. We examined the mutagenesis of seven purified pyrolysis products from tryptophan, lysine, glutamic acid, and soybean globulin with Salmonella typhimurium strain TA98 in the presence of liver fractions from genetically "responsive" C57BL/6N and Ah(b)/Ah(d) or "nonresponsive" DBA/2N and Ah(d)/Ah(d) mice that had been pretreated in vivo with benzo[a]pyrene. For all pyrolysis products tested, mutagenesis is 2-fold to more than 1000-fold greater with C57BL/6N and Ah(b)/Ah(d) than with DBA/2N or Ah(d)/Ah(d) liver fractions. A sucrose density gradient assay for detecting the Ah regulatory gene product, the receptor, was studied with C57BL/6N hepatic cytosol. At levels 100 times in excess of [1,6-(3)H]2,3,7,8-tetrachlorodibenzo-p-dioxin, nonlabeled 2,3,7,8-tetrachlorodibenzo-p-dioxin, 3-methylcholanthrene, and beta-naphthoflavone (inducers of cytochrome P(1)-450) are able to displace the radioligand from its hepatic cytosolic receptor; four pyrolysates from tryptophan, glutamic acid, and soybean globulin did not have this capacity. These data indicate that the pyrolysis products tested, although not effective as inducers of cytochrome P(1)-450, are most mutagenic when metabolized by P(1)-450. Potent P(1)-450 inducers-present in pyrolysates during the combustion process-might be present in quantities insufficient to initiate mutagenesis or carcinogenesis but might have a synergistic action, or act as "comutagens" or "cocarcinogens," with the N-containing heterocyclic pyrolysis products. A quantitative relationship between mutagenic and carcinogenic potency of these pyrolysis products remains, however, to be demonstrated.

  20. Lateral supraorbital approach to ipsilateral PCA-P1 and ICA-PCoA aneurysms

    PubMed Central

    Goehre, Felix; Jahromi, Behnam Rezai; Elsharkawy, Ahmed; Lehto, Hanna; Shekhtman, Oleg; Andrade-Barazarte, Hugo; Munoz, Francisco; Hijazy, Ferzat; Makhkamov, Makhkam; Hernesniemi, Juha

    2015-01-01

    Background: Aneurysms of the posterior cerebral artery (PCA) are rare and often associated with anterior circulation aneurysms. The lateral supraorbital approach allows for a very fast and safe approach to the ipsilateral lesions Circle of Willis. A technical note on the successful clip occlusion of two aneurysms in the anterior and posterior Circle of Willis via this less invasive approach has not been published before. The objective of this technical note is to describe the simultaneous microsurgical clip occlusion of an ipsilateral PCA-P1 and an internal carotid artery - posterior communicating artery (ICA-PCoA) aneurysm via the lateral supraorbital approach. Case Description: The authors present a technical report of successful clip occlusions of ipsilateral located PCA-P1 and ICA-PCoA aneurysms. A 59-year-old female patient was diagnosed with a PCA-P1 and an ipsilateral ICA-PCoA aneurysm by computed tomography angiography (CTA) after an ischemic stroke secondary to a contralateral ICA dissection. The patient underwent microsurgical clipping after a lateral supraorbital craniotomy. The intraoperative indocyanine green (ICG) videoangiography and the postoperative CTA showed a complete occlusion of both aneurysms; the parent vessels (ICA and PCA) were patent. The patient presents postoperative no new neurologic deficit. Conclusion: The lateral supraorbital approach is suitable for the simultaneous microsurgical treatment of proximal anterior circulation and ipsilateral proximal PCA aneurysms. Compared to endovascular treatment, direct visual control of brainstem perforators is possible. PMID:26060600

  1. Lateral supraorbital approach to ipsilateral PCA-P1 and ICA-PCoA aneurysms.

    PubMed

    Goehre, Felix; Jahromi, Behnam Rezai; Elsharkawy, Ahmed; Lehto, Hanna; Shekhtman, Oleg; Andrade-Barazarte, Hugo; Munoz, Francisco; Hijazy, Ferzat; Makhkamov, Makhkam; Hernesniemi, Juha

    2015-01-01

    Aneurysms of the posterior cerebral artery (PCA) are rare and often associated with anterior circulation aneurysms. The lateral supraorbital approach allows for a very fast and safe approach to the ipsilateral lesions Circle of Willis. A technical note on the successful clip occlusion of two aneurysms in the anterior and posterior Circle of Willis via this less invasive approach has not been published before. The objective of this technical note is to describe the simultaneous microsurgical clip occlusion of an ipsilateral PCA-P1 and an internal carotid artery - posterior communicating artery (ICA-PCoA) aneurysm via the lateral supraorbital approach. The authors present a technical report of successful clip occlusions of ipsilateral located PCA-P1 and ICA-PCoA aneurysms. A 59-year-old female patient was diagnosed with a PCA-P1 and an ipsilateral ICA-PCoA aneurysm by computed tomography angiography (CTA) after an ischemic stroke secondary to a contralateral ICA dissection. The patient underwent microsurgical clipping after a lateral supraorbital craniotomy. The intraoperative indocyanine green (ICG) videoangiography and the postoperative CTA showed a complete occlusion of both aneurysms; the parent vessels (ICA and PCA) were patent. The patient presents postoperative no new neurologic deficit. The lateral supraorbital approach is suitable for the simultaneous microsurgical treatment of proximal anterior circulation and ipsilateral proximal PCA aneurysms. Compared to endovascular treatment, direct visual control of brainstem perforators is possible.

  2. Isotope shift of the thallium (6s6p2) 4P1/2 state

    NASA Astrophysics Data System (ADS)

    Wynar, R. H.; Iinuma, M.; Nagourney, W.; Fortson, E. N.

    2003-09-01

    We have measured the hyperfine splitting and level isotope shifts (LIS) of the (6s6p2) 4P1/2 level of 205Tl and 203Tl using laser absorption spectroscopy in a thallium oven near 1373 K. We determine that the hyperfine splitting between the F=1 and 0 levels of the 4P1/2 state in 205Tl is 75.179±0.087 GHz. The F=0 LIS is -7.333±0.025 GHz and the F=1 LIS is -6.500±0.030 GHz, with the 205Tl level below the 203Tl level in both cases. We use our results together with other data to analyze the configuration mixing of the 4P1/2 state with the nearby (6s210s) 2S1/2 state. The mixing inferred from the hyperfine results is consistent with that inferred from the isotope shift results.

  3. Direct Band Gap Gallium Antimony Phosphide (GaSbxP1−x) Alloys

    PubMed Central

    Russell, H. B.; Andriotis, A. N.; Menon, M.; Jasinski, J. B.; Martinez-Garcia, A.; Sunkara, M. K.

    2016-01-01

    Here, we report direct band gap transition for Gallium Phosphide (GaP) when alloyed with just 1–2 at% antimony (Sb) utilizing both density functional theory based computations and experiments. First principles density functional theory calculations of GaSbxP1−x alloys in a 216 atom supercell configuration indicate that an indirect to direct band gap transition occurs at x = 0.0092 or higher Sb incorporation into GaSbxP1−x. Furthermore, these calculations indicate band edge straddling of the hydrogen evolution and oxygen evolution reactions for compositions ranging from x = 0.0092 Sb up to at least x = 0.065 Sb making it a candidate for use in a Schottky type photoelectrochemical water splitting device. GaSbxP1−x nanowires were synthesized by reactive transport utilizing a microwave plasma discharge with average compositions ranging from x = 0.06 to x = 0.12 Sb and direct band gaps between 2.21 eV and 1.33 eV. Photoelectrochemical experiments show that the material is photoactive with p-type conductivity. This study brings attention to a relatively uninvestigated, tunable band gap semiconductor system with tremendous potential in many fields. PMID:26860470

  4. The P1 biomarker for assessing cortical maturation in pediatric hearing loss: a review

    PubMed Central

    Sharma, Anu; Glick, Hannah; Deeves, Emily; Duncan, Erin

    2016-01-01

    We review evidence for a high degree of neuroplasticity of the central auditory pathways in early childhood, citing evidence of studies of the P1 and N1 cortical auditory evoked potentials in congenitally deaf children receiving cochlear implants at different ages during childhood, children with auditory neuropathy spectrum disorder and children with hearing loss and comorbid multiple disabilities. We discuss neuroplasticity, including cortico-cortical de-coupling and cross-modal re-organization that occurs in deafness. We provide evidence for the clinical utility of the P1 cortical auditory evoked potential (CAEP) as a non-invasive biomarker that can be used to objectively assess maturation of auditory cortex in clinical cases of cochlear implant patients and candidates. Finally, we present clinical case studies in which the P1 CAEP biomarker proved useful in clinical decision-making regarding intervention in cases of single-sided deafness, auditory neuropathy spectrum disorder, mild hearing loss and hypoplastic auditory nerve. PMID:27688594

  5. Hereditary Diffuse Infiltrating Retinoblastoma.

    PubMed

    Schedler, Katharina J E; Traine, Peter G; Lohmann, Dietmar R; Haritoglou, Christos; Metz, Klaus A; Rodrigues, Eduardo B

    2016-01-01

    Retinoblastoma is one of the most common childhood cancers. The diffuse infiltrating retinoblastoma is a rare subtype of this neoplasm. The majority of cases of diffuse infiltrating retinoblastoma are unilateral and occur sporadically. Herein we report on a family with three children affected by retinoblastoma, among them one girl with diffuse infiltrating retinoblastoma. This girl was diagnosed at the age of 8 years with a unilateral diffuse infiltrating retinoblastoma. By contrast, the two brothers became clinically apparent in the first 2 years of life with bilateral retinoblastoma. The parents were clinically unremarkable. Genetic analysis of RB1 gene was performed. The girl with diffuse infiltrating RB was found to be heterozygous for an oncogenic mutation in the RB1 gene that was also carried by both brothers and the father of the family. These results show that diffuse infiltrating retinoblastoma can develop on the background of a hereditary predisposition to retinoblastoma.

  6. Correlated diffusion imaging

    PubMed Central

    2013-01-01

    Background Prostate cancer is one of the leading causes of cancer death in the male population. Fortunately, the prognosis is excellent if detected at an early stage. Hence, the detection and localization of prostate cancer is crucial for diagnosis, as well as treatment via targeted focal therapy. New imaging techniques can potentially be invaluable tools for improving prostate cancer detection and localization. Methods In this study, we introduce a new form of diffusion magnetic resonance imaging called correlated diffusion imaging, where the tissue being imaged is characterized by the joint correlation of diffusion signal attenuation across multiple gradient pulse strengths and timings. By taking into account signal attenuation at different water diffusion motion sensitivities, correlated diffusion imaging can provide improved delineation between cancerous tissue and healthy tissue when compared to existing diffusion imaging modalities. Results Quantitative evaluation using receiver operating characteristic (ROC) curve analysis, tissue class separability analysis, and visual assessment by an expert radiologist were performed to study correlated diffusion imaging for the task of prostate cancer diagnosis. These results are compared with that obtained using T2-weighted imaging and standard diffusion imaging (via the apparent diffusion coefficient (ADC)). Experimental results suggest that correlated diffusion imaging provide improved delineation between healthy and cancerous tissue and may have potential as a diagnostic tool for cancer detection and localization in the prostate gland. Conclusions A new form of diffusion magnetic resonance imaging called correlated diffusion imaging (CDI) was developed for the purpose of aiding radiologists in cancer detection and localization in the prostate gland. Preliminary results show CDI shows considerable promise as a diagnostic aid for radiologists in the detection and localization of prostate cancer. PMID:23924150

  7. Gaseous diffusion system

    DOEpatents

    Garrett, George A.; Shacter, John

    1978-01-01

    1. A gaseous diffusion system comprising a plurality of diffusers connected in cascade to form a series of stages, each of said diffusers having a porous partition dividing it into a high pressure chamber and a low pressure chamber, and means for combining a portion of the enriched gas from a succeeding stage with a portion of the enriched gas from the low pressure chamber of each stage and feeding it into one extremity of the high pressure chamber thereof.

  8. Cutting edge: lectin-like transcript-1 is a ligand for the inhibitory human NKR-P1A receptor.

    PubMed

    Rosen, David B; Bettadapura, Jayaram; Alsharifi, Mohammed; Mathew, Porunelloor A; Warren, Hilary S; Lanier, Lewis L

    2005-12-15

    Increasingly, roles are emerging for C-type lectin receptors in immune regulation. One receptor whose function has remained largely enigmatic is human NKR-P1A (CD161), present on NK cells and subsets of T cells. In this study, we demonstrate that the lectin-like transcript-1 (LLT1) is a physiologic ligand for NKR-P1A. LLT1-containing liposomes bind to NKR-P1A+ cells, and binding is inhibited by anti-NKR-P1A mAb. Additionally, LLT1 activates NFAT-GFP reporter cells expressing a CD3zeta-NKR-P1A chimeric receptor; reciprocally, reporter cells with a CD3zeta-LLT1 chimeric receptor are stimulated by NKR-P1A. Moreover, LLT1 on target cells can inhibit NK cytotoxicity via interactions with NKR-P1A.

  9. Phase singularity diffusion.

    PubMed

    Cheng, Xiaojun; Lockerman, Yitzchak; Genack, Azriel Z

    2014-06-01

    We follow the trajectories of phase singularities at nulls of intensity in the speckle pattern of waves transmitted through random media as the frequency of the incident radiation is scanned in microwave experiments and numerical simulations. Phase singularities are observed to diffuse with a linear increase of the square displacement 〈R2〉 with frequency shift. The product of the diffusion coefficient of phase singularities in the transmitted speckle pattern and the photon diffusion coefficient through the random medium is proportional to the square of the effective sample length. This provides the photon diffusion coefficient and a method for characterizing the motion of dynamic material systems.

  10. Inpainting using airy diffusion

    NASA Astrophysics Data System (ADS)

    Lorduy Hernandez, Sara

    2015-09-01

    One inpainting procedure based on Airy diffusion is proposed, implemented via Maple and applied to some digital images. Airy diffusion is a partial differential equation with spatial derivatives of third order in contrast with the usual diffusion with spatial derivatives of second order. Airy diffusion generates the Airy semigroup in terms of the Airy functions which can be rewritten in terms of Bessel functions. The Airy diffusion can be used to smooth an image with the corresponding noise elimination via convolution. Also the Airy diffusion can be used to erase objects from an image. We build an algorithm using the Maple package ImageTools and such algorithm is tested using some images. Our results using Airy diffusion are compared with the similar results using standard diffusion. We observe that Airy diffusion generates powerful filters for image processing which could be incorporated in the usual packages for image processing such as ImageJ and Photoshop. Also is interesting to consider the possibility to incorporate the Airy filters as applications for smartphones and smart-glasses.

  11. Experimental study of vortex diffusers

    SciTech Connect

    Shakerin, S.; Miller, P.L.

    1995-11-01

    This report documents experimental research performed on vortex diffusers used in ventilation and air-conditioning systems. The main objectives of the research were (1) to study the flow characteristics of isothermal jets issuing from vortex diffusers, (2) to compare the vortex diffuser`s performance with that of a conventional diffuser, and (3) to prepare a report that disseminates the results to the designers of ventilation and air-conditioning systems. The researchers considered three diffusers: a conventional round ceiling diffuser and two different styles of vortex diffusers. Overall, the vortex diffusers create slightly more induction of ambient air in comparison to the conventional diffuser.

  12. Improved diffusion coefficients generated from Monte Carlo codes

    SciTech Connect

    Herman, B. R.; Forget, B.; Smith, K.; Aviles, B. N.

    2013-07-01

    Monte Carlo codes are becoming more widely used for reactor analysis. Some of these applications involve the generation of diffusion theory parameters including macroscopic cross sections and diffusion coefficients. Two approximations used to generate diffusion coefficients are assessed using the Monte Carlo code MC21. The first is the method of homogenization; whether to weight either fine-group transport cross sections or fine-group diffusion coefficients when collapsing to few-group diffusion coefficients. The second is a fundamental approximation made to the energy-dependent P1 equations to derive the energy-dependent diffusion equations. Standard Monte Carlo codes usually generate a flux-weighted transport cross section with no correction to the diffusion approximation. Results indicate that this causes noticeable tilting in reconstructed pin powers in simple test lattices with L2 norm error of 3.6%. This error is reduced significantly to 0.27% when weighting fine-group diffusion coefficients by the flux and applying a correction to the diffusion approximation. Noticeable tilting in reconstructed fluxes and pin powers was reduced when applying these corrections. (authors)

  13. Metal Selectivity of a Cd-, Co-, and Zn-Transporting P1B-type ATPase

    PubMed Central

    Smith, Aaron T.; Ross, Matthew O.; Hoffman, Brian M.; Rosenzweig, Amy C.

    2017-01-01

    The P1B-ATPases, a family of transmembrane metal transporters important for transition metal homeostasis in all organisms, are subdivided into classes based on sequence conservation and metal specificity. The multifunctional P1B-4-ATPase CzcP is part of the cobalt, zinc, and cadmium resistance system from the metal-tolerant, model organism Cupriavidus metallidurans. Previous work revealed the presence of an unusual soluble metal-binding domain (MBD) at the CzcP N-terminus, but the nature, extent, and selectivity of the transmembrane metal-binding site (MBS) of CzcP have not been resolved. Using homology modeling, we show that four wholly conserved amino acids from the transmembrane (TM) domain (Met254, Ser474, Cys476, and His807) are logical candidates for the TM MBS, which may communicate with the MBD via interactions with the first TM helix. Metal-binding analyses indicate that wild-type (WT) CzcP has three MBSs, and data on N-terminally truncated (ΔMBD) CzcP suggest the presence of a single TM MBS. Electronic absorption and electron paramagnetic resonance spectroscopic analyses of ΔMBD CzcP and variant proteins thereof provide insight into the details of Co2+ coordination by the TM MBS. These spectroscopic data, combined with in vitro functional studies of WT and variant CzcP proteins, show that the side chains of Met254, Cys476, and His807 contribute to Cd2+, Co2+, and Zn2+ binding and transport, whereas the side chain of Ser474 appears to play a minimal role. By comparison to other P1B-4-ATPases, we suggest that an evolutionarily adapted flexibility in the TM region likely afforded CzcP the ability to transport Cd2+ and Zn2+ in addition to Co2+. PMID:28001366

  14. Bismuth-induced Raman modes in GaP1–xBix

    DOE PAGES

    Christian, Theresa M.; Fluegel, Brian; Beaton, Daniel A.; ...

    2016-09-02

    Here, dilute bismide semiconductor alloys are a promising material platform for optoelectronic devices due to drastic impacts of bismuth on the electronic structure of the alloy. At the same time, the details of bismuth incorporation in the lattice are not fully understood. In this work, we conduct Raman scattering spectroscopy on GaP1- xBix epilayers grown by molecular beam epitaxy (MBE) and identify several bismuth-related Raman features including gap vibration modes at 296, 303, and 314 cm-1. This study paves the way for more detailed analysis of the local symmetry at bismuth incorporation sites in the dilute bismide alloy regime.

  15. VizieR Online Data Catalog: Vilnius photometry of TGU H994 P1 (Straizys+, 2016)

    NASA Astrophysics Data System (ADS)

    Straizys, V.; Cepas, V.; Boyle, R. P.; Munari, U.; Zdanavicius, J.; Maskoliunas, M.; Kazlauskas, A.; Zdanavicius, K.

    2015-11-01

    Table 2 contains the results of photometry of 855 stars down to V~20mag in the Vilnius seven-color system in the three areas of dark cloud TGU H994 P1. The identification numbers, coordinates, V magnitudes, six color indices in the Vilnius system and photometric spectral types are given. The identification numbers start from 1001 to avoid confusion with the catalogue of Cepas et al. (2013BaltA..22..243C, Cat. J/BaltA/22/243). The Coordinates are from PPMXL catalog (Roeser et al. 2010AJ....139.2440R, Cat. I/317). (1 data file).

  16. GALLIUM INDIUM ARSENIDE PHOSPHIDE (GaxIn1-xASyP1-y)

    NASA Astrophysics Data System (ADS)

    Goldberg, Yu. A.; Shmidt, Natalya M.

    The following sections are included: * Basic Parameters at 300 K * Basic Properties of GaxIn1-xASyP1-y Compositions Lattice-Matched to InP at 300 K(x≅0.47y) * Band Structure and Carrier Concentration * Temperature Dependences * Dependence on Hydrostatic Pressure * Band Discontinuities at GaInAsP/InP Heterostructure * Effective Masses * Donors and Acceptors * Electrical Properties * Mobility and Hall Effect * Transport Properties in High Electric Field * Impact Ionization * Recombination Parameters * Optical Properties * Thermal Properties * Mechanical Properties, Elastic Constants, Lattice Vibrations, Other Properties * References

  17. Atomic Geometry of GaAs(110)-p(1×1)-Al

    NASA Astrophysics Data System (ADS)

    Duke, C. B.; Paton, A.; Meyer, R. J.; Brillson, L. J.; Kahn, A.; Kanani, D.; Carelli, J.; Yeh, J. L.; Margaritondo, G.; Katnani, A. D.

    1981-02-01

    An ordered (1×1) structure is formed by evaporating approximately one-half monolayer of Al on GaAs(110) and subsequently annealing at 450°C for 30 min. Both a dynamical analysis of the low-energy electron-diffraction intensities from the resulting half-monolayer of GaAs(110)-p(1×1)-Al structure and soft-x-ray photoemission spectroscopy indicate that the Al replaces the Ga in the second atomic layer beneath the surface. The uppermost layer retains the structure of clean GaAs(110) but is relaxed 0.1 Å toward the second AlAs layer.

  18. Anatomy of Particle Diffusion

    ERIC Educational Resources Information Center

    Bringuier, E.

    2009-01-01

    The paper analyses particle diffusion from a thermodynamic standpoint. The main goal of the paper is to highlight the conceptual connection between particle diffusion, which belongs to non-equilibrium statistical physics, and mechanics, which deals with particle motion, at the level of third-year university courses. We start out from the fact…

  19. Anatomy of Particle Diffusion

    ERIC Educational Resources Information Center

    Bringuier, E.

    2009-01-01

    The paper analyses particle diffusion from a thermodynamic standpoint. The main goal of the paper is to highlight the conceptual connection between particle diffusion, which belongs to non-equilibrium statistical physics, and mechanics, which deals with particle motion, at the level of third-year university courses. We start out from the fact…

  20. Investigating Diffusion with Technology

    ERIC Educational Resources Information Center

    Miller, Jon S.; Windelborn, Augden F.

    2013-01-01

    The activities described here allow students to explore the concept of diffusion with the use of common equipment such as computers, webcams and analysis software. The procedure includes taking a series of digital pictures of a container of water with a webcam as a dye slowly diffuses. At known time points, measurements of the pixel densities…

  1. Adaptation and Cultural Diffusion.

    ERIC Educational Resources Information Center

    Ormrod, Richard K.

    1992-01-01

    Explores the role of adaptation in cultural diffusion. Explains that adaptation theory recognizes the lack of independence between innovations and their environmental settings. Discusses testing and selection, modification, motivation, and cognition. Suggests that adaptation effects are pervasive in cultural diffusion but require a broader, more…

  2. Diffusion of Botulinum Toxins

    PubMed Central

    Brodsky, Matthew A.; Swope, David M.; Grimes, David

    2012-01-01

    Background It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion. Methods This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB). Results Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others. Discussion Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected. PMID:23440162

  3. Galactic Diffuse Emissions

    SciTech Connect

    Digel, Seth W.; /SLAC

    2007-10-25

    Interactions of cosmic rays with interstellar nucleons and photons make the Milky Way a bright, diffuse source of high-energy {gamma}-rays. Observationally, the results from EGRET, COMPTEL, and OSSE have now been extended to higher energies by ground-based experiments, with detections of diffuse emission in the Galactic center reported by H.E.S.S. in the range above 100 GeV and of diffuse emission in Cygnus by MILAGRO in the TeV range. In the range above 100 keV, INTEGRAL SPI has found that diffuse emission remains after point sources are accounted for. I will summarize current knowledge of diffuse {gamma}-ray emission from the Milky Way and review some open issues related to the diffuse emission -- some old, like the distribution of cosmic-ray sources and the origin of the 'excess' of GeV emission observed by EGRET, and some recently recognized, like the amount and distribution of molecular hydrogen not traced by CO emission -- and anticipate some of the advances that will be possible with the Large Area Telescope on GLAST. We plan to develop an accurate physical model for the diffuse emission, which will be useful for detecting and accurately characterizing emission from Galactic point sources as well as any Galactic diffuse emission from exotic processes, and for studying the unresolved extragalactic emission.

  4. The Diffusion of Innovation

    NASA Technical Reports Server (NTRS)

    Earabino, Gerard J.; Heyl, G. Christopher; Percorini, Thomas J.

    1987-01-01

    New ideas encounter obstacles on way to becoming products. Report examines process by which new ideas become products, processes, or accepted standards. Sequence of events called "the diffusion of innovation." Focuses on development of material processing in low gravity as case study in diffusion of innovation.

  5. Investigating Diffusion with Technology

    ERIC Educational Resources Information Center

    Miller, Jon S.; Windelborn, Augden F.

    2013-01-01

    The activities described here allow students to explore the concept of diffusion with the use of common equipment such as computers, webcams and analysis software. The procedure includes taking a series of digital pictures of a container of water with a webcam as a dye slowly diffuses. At known time points, measurements of the pixel densities…

  6. Cosmology with matter diffusion

    SciTech Connect

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field φ which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter σ. The standard ΛCDM model can be recovered by setting σ = 0. If diffusion takes place (σ > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  7. Diffusion in Coulomb crystals.

    PubMed

    Hughto, J; Schneider, A S; Horowitz, C J; Berry, D K

    2011-07-01

    Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions "hop" in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter Γ=175 to Coulomb parameters up to Γ=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

  8. Combustor diffuser interaction program

    NASA Technical Reports Server (NTRS)

    Srinivasan, Ram; Thorp, Daniel

    1986-01-01

    Advances in gas turbine engine performance are achieved by using compressor systems with high stage loading and low part count, which result in high exit Mach numbers. The diffuser and combustor systems in such engines should be optimized to reduce system pressure loss and to maximize the engine thrust-to-weight ratio and minimize length. The state-of-the-art combustor-diffuser systems do not meet these requirements. Detailed understanding of the combustor-diffuser flow field interaction is required for designing advanced gas turbine engines. An experimental study of the combustor-diffuser interaction (CDI) is being conducted to obtain data for the evaluation and improvement of analytical models applicable to a wide variety of diffuser designs. The CDI program consists of four technical phases: Literature Search; Baseline Configuration; Parametric Configurations; and Performance Configurations. Phase 2 of the program is in progress.

  9. Diffusion in Coulomb crystals

    SciTech Connect

    Hughto, J.; Schneider, A. S.; Horowitz, C. J.; Berry, D. K.

    2011-07-15

    Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions ''hop'' in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter {Gamma}=175 to Coulomb parameters up to {Gamma}=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

  10. Immunogenicity of foot-and-mouth disease virus structural polyprotein P1 expressed in transgenic rice.

    PubMed

    Wang, Yuanyuan; Shen, Qin; Jiang, Yunbo; Song, Yunfeng; Fang, Liurong; Xiao, Shaobo; Chen, Huanchun

    2012-04-01

    Transgenic plants have become developed as bioreactors for producing heterologous proteins and may even form edible vaccines. In the present study, a transgenic rice expressing the capsid precursor polypeptide (P1) gene of foot-and-mouth disease virus (FMDV), under the control of a dual cauliflower mosaic virus (CaMV 35S) promoter, was generated by Agrobacterium-mediated transformation. Southern blot, northern blot, western blot, and ELISA analyses confirmed that the P1 gene was integrated into the transgenic rice and the protein was expressed specifically in the leaves at levels of 0.6-1.3 μg/mg of total soluble protein. After intraperitoneal immunization of mice with crude protein extracts from transgenic rice plants, FMDV-specific neutralizing antibodies were detected. The immunized mice could clear virus from their sera after FMDV challenge. In addition, FMDV-specific mucosal immune responses were detected in mice after oral immunization with protein extracts from transgenic rice plants. Partial virus clearance was obtained after FMDV challenge. These results indicate the potential of using a transgenic rice-based expression system as an alternative bioreactor for FMDV subunit vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. FURTHER CONSTRAINTS ON THE OPTICAL TRANSMISSION SPECTRUM OF HAT-P-1b

    SciTech Connect

    Montalto, M.; Santos, N. C.; Martins, J. H. C.; Figueira, P.; Alonso, R.; Iro, N.; Desidera, S.

    2015-09-20

    We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo. Our measurements imply an average planet to star radius ratio equal to R{sub p}/R{sub *} = (0.1159 ± 0.0005). This result is consistent with the value obtained from recent near-infrared measurements of this object, but differs from previously reported optical measurements, being lower by around 4.4 exoplanet scale heights. Analyzing the data over five different spectral bins of ∼600 Å wide, we observed a single peaked spectrum (3.7 σ level) with a blue cutoff corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in-between 6180 and 7400 Å. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported.

  12. Optimization of nonribosomal peptides production by a psychrotrophic fungus: Trichoderma velutinum ACR-P1.

    PubMed

    Sharma, Richa; Singh, Varun P; Singh, Deepika; Yusuf, Farnaz; Kumar, Anil; Vishwakarma, Ram A; Chaubey, Asha

    2016-11-01

    Trichoderma is an anamorphic filamentous fungal genus with immense potential for production of small valuable secondary metabolites with indispensable biological activities. Microbial dynamics of a psychrotrophic strain Trichoderma velutinum ACR-P1, isolated from unexplored niches of the Shiwalik region, bestowed with rich biodiversity of microflora, was investigated for production of nonribosomal peptides (NRPs) by metabolite profiling by intact-cell mass spectrometry (ICMS) employing matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer. Being the first report on NRPs production by T. velutinum, studies on optimization of growth conditions by Response Surface Methodology (RSM) for production of NRPs by ACR-P1 was carried out strategically. Multifold enhancement in the yield of NRPs belonging to subfamily SF4 with medium chain of amino acid residues having m/z 1437.9, 1453.9, and 1452.0 at pH 5.9 at 20 °C and of subfamily SF1 with long-chain amino acid residues having m/z 1770.2, 1784.2, 1800.1, 1802.1, and 1815.1 was achieved at pH 7.0 at 25 °C. Complexities of natural mixtures were thus considerably reduced under respective optimized culture conditions accelerating the production of novel microbial natural products by saving time and resources.

  13. ON BOUNDARY VALUES IN L_p, p > 1, OF SOLUTIONS OF ELLIPTIC EQUATIONS

    NASA Astrophysics Data System (ADS)

    Guščin, A. K.; Mihaĭlov, V. P.

    1980-02-01

    The behavior near the boundary of generalized solutions of a second order elliptic equation \\displaystyle \\sum_{i,j=1}^n\\frac{\\partial}{\\partial x_i}\\biggl(a_{ij}(x)\\fra......artial x_j}\\biggr)=f,\\qquad x\\in Q=\\{\\vert x\\vert < 1\\}\\subset\\mathbf{R}_n,in W_p^1(\\mathcal{Q}), p > 1, is studied. It is shown that under a certain condition on the right side of the equation, the boundedness of the function \\Vert x\\Vert_{L_p(\\vert x\\vert=r)}, \\frac{1}{2}\\le r < 1, is necessary and sufficient for the existence of a limit for the solution u(rw), \\frac{1}{2}\\le r < 1, \\vert w\\vert=1, in L_p(\\vert w\\vert=1) as r\\to 1 - 0. Moreover, the summability of the function \\displaystyle (1-\\vert x\\vert)\\vert u(x)\\vert^{p - 2}\\vert\

  14. Integrated P1 Hohlraum/Capsule Simulations with Comparison to Neutron and X-Ray Measurements

    NASA Astrophysics Data System (ADS)

    Eder, D. C.; Spears, B. K.; Town, R. P.; Jones, O. S.; Munro, D. H.; Peterson, J. L.; Ma, T.; Pak, A. K.; Benedetti, L. R.; Hatchett, S. P.; Knauer, J. P.; MacKinnon, A. J.; Yeamans, C. B.; McNaney, J. M.; Casey, D. T.; NIF Team

    2013-10-01

    We discuss integrated hohlraum/capsule simulations that drive a DT symcap capsule downward in a NIF experiment by increasing/decreasing the peak power in the upper/lower laser beams by 8%. This laser asymmetry results in a radiation drive P1/P0 at the capsule ablation surface of 2% and a downward capsule velocity of 125 microns/ns. The simulation shows small (<1%) changes in the P2 and P4 moments of the x-ray self-emission as compared to a simulation with no laser asymmetry. The calculated reduction in yield due to the induced P1 is 20%. Simulations for DT layered capsules for comparable velocities have yields an order of magnitude lower than simulations with stationary capsules. The velocity is measured by comparing the arrival times of DD and DT neutrons at detectors located at different locations. Preliminary data from a recent shot gives a downward velocity of order 100 microns/ns consistent with simulations. We also compare pre- and post-shot simulations with x-ray images at different energies. The ability to correct for capsule velocity, e.g., due to different upper/lower crossbeam transfer energies, is another tool in the quest for ignition. This work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-640047.

  15. Photometric investigation of the comet C/2009 P1 (Garradd) at pre-perihelion

    NASA Astrophysics Data System (ADS)

    Ivanova, A.; Borysenko, S.; Andreev, M.

    2014-07-01

    We present an analysis of the photometric observations of comet C/2009 P1 (Garradd). The comet was observed at the heliocentric distance of 1.7 au and the geocentric distance of 2.0 au. Observations were obtained with the 60-cm telescope Zeiss-600 (ICAMER, KB). Narrow-band filters were used for selecting the BC (λ4450/67 Å), GC (λ5260/56 Å), RC (λ7128/58 Å), continuum, and C_2 (λ5141/118 Å), CN (λ3870/62 Å), and C_3 (λ4062/62 Å) emissions. The production rate for dust particles and the spectral gradient of reflectivity of the dust in the blue and red continuum have been obtained from the photometric observations. The following quantities have been estimated: the column density of molecules and their production rates. According to our results, the physical parameters of comet C/2009 P1 (Garradd) are close to the average characteristics of typical dynamically new comets and Oort cloud comets.

  16. Quenching of I(2P 1/2) by O 3 and O( 3P)

    NASA Astrophysics Data System (ADS)

    Azyazov, V. N.; Antonov, I. O.; Ruffner, S.; Heaven, M. C.

    2006-02-01

    Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P 1/2) by O atoms and O 3 may impact the efficiency of discharge driven iodine lasers. In the present study we have measured the rate constants for quenching of I(2P 1/2) by O( 3P) atoms and O 3 using pulsed laser photolysis techniques. The rate constant for quenching by O 3, 1.8x10 -12 cm 3 s -1, was found to be a factor of five smaller than the literature value. The rate constant for quenching by O( 3P) was 1.2x10 -11 cm 3 s -1. This was six times larger than a previously reported upper bound, but consistent with estimates obtained by modeling the kinetics of discharge-driven laser systems.

  17. DSC deconvolution of the structural complexity of c-MYC P1 promoter G-quadruplexes.

    PubMed

    Dettler, Jamie M; Buscaglia, Robert; Le, Vu H; Lewis, Edwin A

    2011-03-16

    We completed a biophysical characterization of the c-MYC proto-oncogene P1 promoter quadruplex and its interaction with a cationic porphyrin, 5,10,15,20-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4), using differential scanning calorimetry, isothermal titration calorimetry, and circular dichroism spectroscopy. We examined three different 24-mer oligonucleotides, including the wild-type (WT) sequence found in the c-MYC P(1) promoter and two mutant G→T sequences that are known to fold into single 1:2:1 and 1:6:1 loop isomer quadruplexes. Biophysical experiments were performed on all three oligonucleotide sequences at two different ionic strengths (30 mM [K(+)] and 130 mM [K(+)]). Differential scanning calorimetry experiments demonstrated that the WT quadruplex consists of a mixture of at least two different folded conformers at both ionic strengths, whereas both mutant sequences exhibit a single two-state melting transition at both ionic strengths. Isothermal titration calorimetry experiments demonstrated that both mutant sequences bind 4 mols of TMPyP4 to 1 mol of DNA, in similarity to the WT sequence. The circular dichroism spectroscopy signatures for all three oligonucleotides at both ionic strengths are consistent with an intramolecular parallel stranded G-quadruplex structure, and no change in quadruplex structure is observed upon addition of saturating amounts of TMPyP4 (i.e., 4:1 TMPyP4/DNA).

  18. Cloned rainbow trout liver P(1)450 complementary DNA as a potential environmental monitor

    SciTech Connect

    Haasch, M.L.; Wejksnora, P.J.; Stegeman, J.J.; Lech, J.J.

    1989-04-01

    A technique is proposed for the biological monitoring of pollutants in aquatic environments by use of a complementary DNA (cDNA) probe. The induction of hepatic cytochrome P(1)450 mRNA has been investigated utilizing pfP(1)450-3', a 3'-specific 1.5 kb cDNA clone derived from 3-methylcholanthrene-inducible mRNA of rainbow trout. A time course of induction of both the hybridizable mRNA and hepatic monooxygenase catalytic activity in rainbow trout with a known inducer in fish, beta-naphthoflavone, was studied. The cDNA probe was also shown to hybridize with induced mRNA of brook trout, scup, garter snake, painted turtle, and rat demonstrating the suitability of the probe for examining induction of mRNA in various species. The results of these experiments suggest that the cDNA probe may be useful as a biological monitoring tool for determining the presence and effects of chemical pollutants which are inducers of hepatic microsomal monooxygenase activity. The probe may have the potential to be applied as an early warning system in the monitoring of water quality.

  19. En1 directs superior olivary complex neuron positioning, survival, and expression of FoxP1.

    PubMed

    Altieri, Stefanie C; Jalabi, Walid; Zhao, Tianna; Romito-DiGiacomo, Rita R; Maricich, Stephen M

    2015-12-01

    Little is known about the genetic pathways and transcription factors that control development and maturation of central auditory neurons. En1, a gene expressed by a subset of developing and mature superior olivary complex (SOC) cells, encodes a homeodomain transcription factor important for neuronal development in the midbrain, cerebellum, hindbrain and spinal cord. Using genetic fate-mapping techniques, we show that all En1-lineal cells in the SOC are neurons and that these neurons are glycinergic, cholinergic and GABAergic in neurotransmitter phenotype. En1 deletion does not interfere with specification or neural fate of these cells, but does cause aberrant positioning and subsequent death of all En1-lineal SOC neurons by early postnatal ages. En1-null cells also fail to express the transcription factor FoxP1, suggesting that FoxP1 lies downstream of En1. Our data define important roles for En1 in the development and maturation of a diverse group of brainstem auditory neurons.

  20. Purification and characterization of Luffin P1, a ribosome-inactivating peptide from the seeds of Luffa cylindrica.

    PubMed

    Li, Feng; Yang, Xin-xiu; Xia, Hen-chuan; Zeng, Rong; Hu, Wei-guo; Li, Zhen; Zhang, Zu-chuan

    2003-06-01

    A peptide designated Luffin P1 was purified from the seeds of Luffa cylindrica. Its molecular mass was determined to be 5226.1 Da by MALDI-TOF MS analysis. The purified Luffin P1 shows a strong inhibitory activity on protein synthesis in the cell-free rabbit reticulocyte lysate with IC(50) of 0.88 nM. Its reaction mechanism is the same as that of the ribosome-inactivating protein trichosanthin, which is an rRNA N-glycosidase. Besides, the results of gel filtration chromatography suggested the existence of polymers of Luffin P1 and polymerization of Luffin P1 enhanced its rRNA N-glycosidase activity. Luffin P1 was the smallest peptide yet reported that has translational inhibitory activity. The cDNA and deduced amino acid sequence of Luffin P1 has also been determined.

  1. Helium Diffusion in Olivine

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.

    2011-12-01

    Diffusion of helium has been characterized in natural Fe-bearing olivine (~Fo90) and synthetic forsterite. Polished, oriented slabs of olivine were implanted with 3He, at 100 keV at a dose of 5x1015/cm2 or at 3.0 MeV at a dose of 1x1016/cm2. A set of experiments on the implanted olivine were run in 1-atm furnaces. In addition to the one-atm experiments, experiments on implanted samples were also run at higher pressures (2.6 and 2.7 GPa) to assess the potential effects of pressure on He diffusion and the applicability of the measured diffusivities in describing He transport in the mantle. The high-pressure experiments were conducted in a piston-cylinder apparatus using an "ultra-soft" pressure cell, with the diffusion sample directly surrounded by AgCl. 3He distributions following experiments were measured with Nuclear Reaction Analysis using the reaction 3He(d,p)4He. This direct profiling method permits us to evaluate anisotropy of diffusion, which cannot be easily assessed using bulk-release methods. For diffusion in forsterite parallel to c we obtain the following Arrhenius relation over the temperatures 250-950°C: D = 3.91x10-6exp(-159 ± 4 kJ mol-1/RT) m2/sec. The data define a single Arrhenius line spanning more than 7 orders of magnitude in D and 700°C in temperature. Diffusion parallel to a appears slightly slower, yielding an activation energy for diffusion of 135 kJ/mol and a pre-exponential factor of 3.73x10-8 m2/sec. Diffusion parallel to b is slower than diffusion parallel to a (by about two-thirds of a log unit); for this orientation an activation energy of 138 kJ/mol and a pre-exponential factor of 1.34x10-8 m2/sec are obtained. This anisotropy is broadly consistent with observations for diffusion of Ni and Fe-Mg in olivine. Diffusion in Fe-bearing olivine (transport parallel to b) agrees within uncertainty with findings for He diffusion in forsterite. The higher-pressure experiments yield diffusivities in agreement with those from the 1-atm

  2. Helium diffusion in carbonates

    NASA Astrophysics Data System (ADS)

    Amidon, W. H.; Cherniak, D. J.; Watson, E. B.; Hobbs, D.

    2013-12-01

    The abundance and large grain size of carbonate minerals make them a potentially attractive target for 4He thermochronology and 3He cosmogenic dating, although the diffusive properties of helium in carbonates remain poorly understood. This work characterizes helium diffusion in calcite and dolomite to better understand the crystal-chemical factors controlling He transport and retentivity. Slabs of cleaved natural calcite and dolomite, and polished sections of calcite cut parallel or normal to c, were implanted with 3He at 3 MeV with a dose of 5x1015/cm2. Implanted carbonates were heated in 1-atm furnaces, and 3He distributions following diffusion anneals were profiled with Nuclear Reaction Analysis using the reaction 3He(d,p)4He. For 3He transport normal to cleavage surfaces in calcite, we obtain the following Arrhenius relation over the temperature range 78-300°C: Dcalcite = 9.0x10-9exp(-55 × 6 kJ mol-1/RT) m2sec-1. Diffusion in calcite exhibits marked anisotropy, with diffusion parallel to c about two orders of magnitude slower than diffusion normal to cleavage faces. He diffusivities for transport normal to the c-axis are similar in value to those normal to cleavage surfaces. Our findings are broadly consistent with helium diffusivities from step-heating measurements of calcite by Copeland et al. (2007); these bulk degassing data may reflect varying effects of diffusional anisotropy. Helium diffusion normal to cleavage surfaces in dolomite is significantly slower than diffusion in calcite, and has a much higher activation energy for diffusion. For dolomite, we obtain the following Arrhenius relation for He diffusion over the temperature range 150-400°C: Ddolomite = 9.0x10-8exp(-92 × 9 kJ mol-1/RT) m2sec-1. The role of crystallographic structure in influencing these differences among diffusivities was evaluated using the maximum aperture approach of Cherniak and Watson (2011), in which crystallographic structures are sectioned along possible diffusion

  3. Epigenetic Modifications of Distinct Sequences of the p1 Regulatory Gene Specify Tissue-Specific Expression Patterns in Maize

    PubMed Central

    Sekhon, Rajandeep S.; Peterson, Thomas; Chopra, Surinder

    2007-01-01

    Tandemly repeated endogenous genes are common in plants, but their transcriptional regulation is not well characterized. In maize, the P1-wr allele of pericarp color1 is composed of multiple copies arranged in a head-to-tail fashion. P1-wr confers a white kernel pericarp and red cob glume pigment phenotype that is stably inherited over generations. To understand the molecular mechanisms that regulate tissue-specific expression of P1-wr, we have characterized P1-wr*, a spontaneous loss-of-function epimutation that shows a white kernel pericarp and white cob glume phenotype. As compared to its progenitor P1-wr, the P1-wr* is hypermethylated in exon 1 and intron 2 regions. In the presence of the epigenetic modifier Ufo1 (Unstable factor for orange1), P1-wr* plants exhibit a range of cob glume pigmentation whereas pericarps remain colorless. In these plants, the level of cob pigmentation directly correlates with the degree of DNA demethylation in the intron 2 region of p1. Further, genomic bisulfite sequencing indicates that a 168-bp region of intron 2 is significantly hypomethylated in both CG and CNG context in P1-wr* Ufo1 plants. Interestingly, P1-wr* Ufo1 plants did not show any methylation change in a distal enhancer region that has previously been implicated in Ufo1-induced gain of pericarp pigmentation of the P1-wr allele. These results suggest that distinct regulatory sequences in the P1-wr promoter and intron 2 regions can undergo independent epigenetic modifications to generate tissue-specific expression patterns. PMID:17179091

  4. Thorium Diffusion in Monazite

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.

    2006-05-01

    Diffusion of thorium has been characterized in synthetic monazite under dry conditions. The synthetic monazites (either pure CePO4, NdPO4, or a mixed LREE phosphate containing Ce, Nd, and Sm) were grown via a Na2CO3-MoO3 flux method. The source of diffusant for the experiments were either synthesized ThSiO4 or CaTh(PO4)2 powders. Experiments were performed by placing source and monazite in Pt capsules and annealing capsules in 1 atm furnaces for times ranging from 10 days to a few hours, at temperatures from 1400 to 1550C. The Th distributions in the monazite were profiled by Rutherford Backscattering Spectrometry (RBS). The following Arrhenius relation was obtained for diffusion in monazite: DSm = 7.2x103 exp(-814 kJ mol-1/RT) m2sec-1 The diffusivity of Th was similar for monazites containing a single REE and the mixed LREE phosphates. Th diffusion was also similar for experiments run using the Th silicate and Ca-Th phosphate sources, suggesting that the substitutional mechanism for Th in monazite, i.e, Th+4 + Si+4 for REE+3 + P+5 with the ThSiO4 source, and Th+4 + Ca+2 for 2REE+3 with the CaTh(PO4)2 source, does not significantly affect Th diffusivities, and that Th is likely the rate-limiting species. Th diffusion in monazite is about 4 orders of magnitude slower than Pb diffusion (Cherniak et al., 2004). This contrasts with findings of Gardes et al. (2005) who determined that Pb, Th and REE diffusivities in monazite are similar. Th diffusion in zircon (Cherniak et al., 1997) is about an order of magnitude slower than in monazite, but with similar activation energy for diffusion. The smaller diffusivities in zircon may be a consequence of the larger disparity in size between Th and the Zr site in zircon as compared with Th and the REE site in monazite. Nonetheless, Th is essentially immobile in monazite with respect to exchange by volume diffusion under most geologic conditions; these findings may have implications for containment of high- level actinide

  5. Structural and optical investigation of InAsxP1-x/InP strained superlattices

    NASA Astrophysics Data System (ADS)

    Lamberti, C.; Bordiga, S.; Boscherini, F.; Mobilio, S.; Pascarelli, S.; Gastaldi, L.; Madella, M.; Papuzza, C.; Rigo, C.; Soldani, D.; Ferrari, C.; Lazzarini, L.; Salviati, G.

    1998-01-01

    We report a complete characterization of InAsxP1-x/InP (0.05P1-x/InP layers (10-20 Å) are obtained by P↔As substitutions effects. Arsenic composition of the so obtained layers depends both on AsH3 flux intensity and exposure times. Samples have been characterized by means of high resolution x-ray diffraction, high resolution transmission electron microscopy, 4 K photoluminescence, and extended x ray absorption fine structure spectroscopy. The combined use of high resolution x-ray diffraction and of 4 K photoluminescence, with related simulations, allows us to predict both InAsP composition and width, which are qualitatively confirmed by electron microscopy. Our study indicates that the effect of the formation of thin InAsP layers is due to the As incorporation onto the InP surface exposed to the As flux during the AsH3 exposure, rather than the residual As pressure in the growth chamber during InP growth. Arsenic K-edge extended x-ray absorption fine structure analysis shows that the first shell environment of As at these interfaces is similar to that found in bulk InAsxP1-x alloys of similar composition. In particular we measure an almost constant As-In bond length (within 0.02 Å), independent of As concentration; this confirms that epitaxy with InP is accompanied by local structural distortions, such as bond angle variations, which accommodate the nearly constant As-In bond length. In our investigation we characterize not only very high quality heterostructures but also samples showing serious interface problems such as nonplanarity and/or a consistent chemical spread along the growth axis. In the study presented here we thus propose a general method, based on

  6. Tungsten diffusion in silicon

    SciTech Connect

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B.; Portavoce, A.; Grosjean, C.

    2014-01-07

    Two doses (10{sup 13} and 10{sup 15} cm{sup −2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960 °C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  7. Diffusion Flame Stabilization

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Katta, Viswanath R.

    2007-01-01

    Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm) (Fig. 1, left). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated (Fig. 1, right). A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

  8. Diffusion Flame Stabilization

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Katta, V. R.

    2006-01-01

    Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated. A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

  9. The lost p1 allele in sh2 sweet corn: Quantitative effects of p1 and a1 genes on the concentrations of maysin, apimaysin, methoxymaysin, and chlorogenic acid in maize silk, and the antibiotic activity against corn earworm

    USDA-ARS?s Scientific Manuscript database

    The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has very little genetic variation for resistance to insects. This presentation will review and summarize the studies of the functions of two loci, p1 and a1. The P1 allele can have a major role in the resista...

  10. Structural characterization of P1'-diversified urea-based inhibitors of glutamate carboxypeptidase II.

    PubMed

    Pavlicek, Jiri; Ptacek, Jakub; Cerny, Jiri; Byun, Youngjoo; Skultetyova, Lubica; Pomper, Martin G; Lubkowski, Jacek; Barinka, Cyril

    2014-05-15

    Urea-based inhibitors of human glutamate carboxypeptidase II (GCPII) have advanced into clinical trials for imaging metastatic prostate cancer. In parallel efforts, agents with increased lipophilicity have been designed and evaluated for targeting GCPII residing within the neuraxis. Here we report the structural and computational characterization of six complexes between GCPII and P1'-diversified urea-based inhibitors that have the C-terminal glutamate replaced by more hydrophobic moieties. The X-ray structures are complemented by quantum mechanics calculations that provide a quantitative insight into the GCPII/inhibitor interactions. These data can be used for the rational design of novel glutamate-free GCPII inhibitors with tailored physicochemical properties.

  11. As-built design specification for P1A software system modified display subsystem

    NASA Technical Reports Server (NTRS)

    Horton, C. L.; Story, A. S. (Principal Investigator)

    1980-01-01

    This document contains the design of the proportional estimate processor which was written to satisfy the software requirement of Part A of the P1A experiment. The purposes of the project are: (1) to select the dots to be labelled; (2) to create tables of green numbers and brightness values for all selected dots per acquisition; (3) to create scatter plots of green numbers vs brightness for each acquisition for all selected dots. If labels have been provided then scatter plots of only categories of interest can be optionally produced; and (4) to produce trajectory plots of green number vs brightness at differing acquisition times for each dot. These plots need to be in the same order as the list of selected dots. When labels are provided only plots of dots of categories of interest are to be produced.

  12. The tripartite immunity system of phages P1 and P7.

    PubMed

    Heinrich, J; Velleman, M; Schuster, H

    1995-08-01

    Prophages P1 and P7 exist as unit copy DNA plasmids in the bacterial cell. Maintenance of the prophage state requires the continuous expression of two repressors: (i) C1 is a protein which negatively regulates the expression of lytic genes including the C1 inactivator gene coi, and (ii) C4 is an antisense RNA which specifically inhibits the synthesis of an anti-repressor Ant. In addition, C1 repression is strengthened by lxc encoding an auxiliary repressor protein. The repressors C1, C4 and Lxc are components of a tripartite immunity system of the two phages. Here, the mode of action of these regulatory components including their antagonists Coi and Ant is described.

  13. Anomalous photoluminescence in InP1−xBix

    PubMed Central

    Wu, Xiaoyan; Chen, Xiren; Pan, Wenwu; Wang, Peng; Zhang, Liyao; Li, Yaoyao; Wang, Hailong; Wang, Kai; Shao, Jun; Wang, Shumin

    2016-01-01

    Low temperature photoluminescence (PL) from InP1−xBix thin films with Bi concentrations in the 0–2.49% range reveals anomalous spectral features with strong and very broad (linewidth of 700 nm) PL signals compared to other bismide alloys. Multiple transitions are observed and their energy levels are found much smaller than the band-gap measured from absorption measurements. These transitions are related to deep levels confirmed by deep level transient spectroscopy, which effectively trap free holes and enhance radiative recombination. The broad luminescence feature is beneficial for making super-luminescence diodes, which can theoretically enhance spatial resolution beyond 1 μm in optical coherent tomography (OCT). PMID:27291823

  14. The P1-RKDG method for two-dimensional Euler equations of gas dynamics

    NASA Technical Reports Server (NTRS)

    Cockburn, Bernardo; Shu, Chi-Wang

    1991-01-01

    A class of nonlinearly stable Runge-Kutta local projection discontinuous Galerkin (RKDG) finite element methods for conservation laws is investigated. Two dimensional Euler equations for gas dynamics are solved using P1 elements. The generalization of the local projections, which for scalar nonlinear conservation laws was designed to satisfy a local maximum principle, to systems of conservation laws such as the Euler equations of gas dynamics using local characteristic decompositions is discussed. Numerical examples include the standard regular shock reflection problem, the forward facing step problem, and the double Mach reflection problem. These preliminary numerical examples are chosen to show the capacity of the approach to obtain nonlinearly stable results comparable with the modern nonoscillatory finite difference methods.

  15. Infrared diffuse interstellar bands

    NASA Astrophysics Data System (ADS)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

    2017-05-01

    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  16. Diffusion in monodisperse ferrofluids

    NASA Astrophysics Data System (ADS)

    Peredo-Ortíz, R.; Hernández-Contreras, M.; Hernández Gómez, R.

    2017-01-01

    The diffusion coefficients characterizing the translational and rotational Brownian motion of a particle in a concentrated suspension were determined in the long time diffusive regime for a ferrofluid suspension with the use of a Langevin equation approach. These dynamical properties depend on the equilibrium micro-structural information of the suspension and take into account the effect of direct anisotropic inter-particle's interactions on self-diffusion. The comparison of this theory with Brownian dynamic simulations results is made in terms of colloid density and dipole interaction strength.

  17. SPITZER IRAC SECONDARY ECLIPSE PHOTOMETRY OF THE TRANSITING EXTRASOLAR PLANET HAT-P-1b

    SciTech Connect

    Todorov, Kamen; Deming, Drake; Harrington, Jospeph; Stevenson, Kevin B.; Bowman, William C.; Nymeyer, Sarah; Fortney, Jonathan J.; Bakos, Gaspar A.

    2010-01-01

    We report Spitzer/IRAC photometry of the transiting giant exoplanet HAT-P-1b during its secondary eclipse. This planet lies near the postulated boundary between the pM and pL-class of hot Jupiters, and is important as a test of models for temperature inversions in hot Jupiter atmospheres. We derive eclipse depths for HAT-P-1b, in units of the stellar flux, that are: 0.080% +- 0.008% [3.6 mum], 0.135% +- 0.022% [4.5 mum], 0.203% +- 0.031% [5.8 mum], and 0.238% +- 0.040% [8.0 mum]. These values are best fit using an atmosphere with a modest temperature inversion, intermediate between the archetype inverted atmosphere (HD 209458b) and a model without an inversion. The observations also suggest that this planet is radiating a large fraction of the available stellar irradiance on its dayside, with little available for redistribution by circulation. This planet has sometimes been speculated to be inflated by tidal dissipation, based on its large radius in discovery observations, and on a non-zero orbital eccentricity allowed by the radial velocity data. The timing of the secondary eclipse is very sensitive to orbital eccentricity, and we find that the central phase of the eclipse is 0.4999 +- 0.0005. The difference between the expected and observed phase indicates that the orbit is close to circular, with a 3sigma limit of |e cos omega| < 0.002.

  18. [Distribution in different Salmonella serovars and integration sites of Salmonella paratyphi C phage SPC-P1].

    PubMed

    Zhao, Pan; Peng, Yi-hong; Zou, Qing-hua

    2015-12-18

    To determine the prevalence of Salmonella paratyphi C phage (SPC-P1) in different Salmonella serovars and to identify the integration sites in host genome. Based on the complete genome of SPC-P1 in S. paratyphi C RKS4594, 6 pairs of primers were designed and used to amplify the fragments of SPC-P1 in 11 S. typhi, 11 S. paratyphi A, 12 S. paratyphi B and 23 S. paratyphi C strains. At the same time, 100 complete genomes of Salmonella including 20 serovars available in National Center for Biotechnology Information (NCBI) database were downloaded and aligned by Mauve 2.3.1 to determine the prevalence of SPC-P1 in these serovars. Primers were designed according to the integration sites of SPC-P1 in the genome of RKS4594, and used to amplify ten strains having SPC-P1 in the genome. The PCR products were sequenced to investigate the integration sites of SPC-P1. SPC-P1 was widely distributed in S.paratyphi C genome. In the study, 14 strains had all 6 fragments and 2 strains had 3-5 fragments. All the amplified fragments showed expected sizes. In contrast, in the genomes of S. typhi, S. paratyphi A and S. paratyphi B, no or only 1-2 fragments could be amplified, and the sizes were smaller than expected. The results from Mauve showed that only in the genome of S.choleraesuis, which was a close relative of S. paratyphi C, there existed an almost complete genome of SPC-P1. The insertion site of SPC-P1 in all the ten S. paratyphi C strains tested was between pgtE and yfdC genes. SPC-P1 is a unique virulence factor of S. paratyphi C. It may play roles in the host range and pathogenicity of S.paratyphi C.

  19. Diffusion of eccentric microswimmers.

    PubMed

    Debnath, Debajyoti; Ghosh, Pulak K; Li, Yunyun; Marchesoni, Fabio; Li, Baowen

    2016-02-21

    We model the two-dimensional diffusive dynamics of an eccentric artificial microswimmer in a highly viscous medium. We assume that the swimmer's propulsion results from an effective force applied to a center distinct from its center of mass, both centers resting on a body's axis parallel to its average self-propulsion velocity. Moreover, we allow for angular fluctuations of the velocity about the body's axis. We prove, both analytically and numerically, that the ensuing active diffusion of the swimmer is suppressed to an extent that strongly depends on the model parameters. In particular, the active diffusion constant undergoes a transition from a quadratic to a linear dependence on the self-propulsion speed, with practical consequences on the interpretation of the experimental data. Finally, we extend our model to describe the diffusion of chiral eccentric swimmers.

  20. Novel Diffusivity Measurement Technique

    NASA Technical Reports Server (NTRS)

    Rashidnia, Nasser

    2001-01-01

    A common-path interferometer (CPI) system was developed to measure the diffusivity of liquid pairs. The CPI is an optical technique that can be used to measure changes in the gradient of the refraction index of transparent materials. This system uses a shearing interferometer that shares the same optical path from a laser light source to the final imaging plane. Hence, the molecular diffusion coefficient of liquids can be determined using the physical relations between changes in the optical path length and the liquid phase properties. The data obtained with this interferometer were compared with similar results from other techniques and demonstrated that the instrument is superior in measuring the diffusivity of miscible liquids while keeping the system very compact and robust. CPI can also be used for studies in interface dynamics and other diffusion-dominated-process applications.

  1. Factorized Diffusion Map Approximation

    PubMed Central

    Amizadeh, Saeed; Valizadegan, Hamed; Hauskrecht, Milos

    2013-01-01

    Diffusion maps are among the most powerful Machine Learning tools to analyze and work with complex high-dimensional datasets. Unfortunately, the estimation of these maps from a finite sample is known to suffer from the curse of dimensionality. Motivated by other machine learning models for which the existence of structure in the underlying distribution of data can reduce the complexity of estimation, we study and show how the factorization of the underlying distribution into independent subspaces can help us to estimate diffusion maps more accurately. Building upon this result, we propose and develop an algorithm that can automatically factorize a high dimensional data space in order to minimize the error of estimation of its diffusion map, even in the case when the underlying distribution is not decomposable. Experiments on both the synthetic and real-world datasets demonstrate improved estimation performance of our method over the standard diffusion-map framework. PMID:25309676

  2. Hydrogen Diffusion in Forsterite

    NASA Astrophysics Data System (ADS)

    Demouchy, S.; Mackwell, S.

    2002-12-01

    Physical and chemical properties of Earth's mantle are readily modified by interaction with volatiles, such as water. Thus, characterization of solubility and kinetics of incorporation for water in nominally anhydrous minerals is important in order to understand the behavior of Earth's interior under hydrous conditions. Experimental studies on the olivine-water system indicate that significant amounts of OH can dissolve within olivine as point defects (Bell and Rossman, 1992; Kohlstedt et al. 1996). Extending Kohlstedt and Mackwell's (1998) work, our study concerns the kinetics of hydrogen transport in the iron-free olivine-water system. This study is based on hydrogenation of forsterite samples during piston-cylinder and TZM cold-seal vessel experiments. We use infrared analyses in order to constrain the speciation of the mobile water-derived defects in forsterite single-crystal sample, and the rates of diffusion of such species under uppermost mantle conditions (0.2 to 1.5 GPa, 900 to 1100° C). Hydrogen defect transport in single crystals of forsterite is investigated for diffusion parallel to each crystallographic axis. Defect diffusivities are obtained by fitting a diffusion law to the OH content as a function of position in the sample. Our current results indicate that incorporation of hydroxyl species into iron-free olivine is a one-stage process with hydrogen diffusion linked to magnesium vacancy self-diffusion DV, such that DV = D~/3 = 10-12 m2/s at 1000° C parallel to [001], where D~ represents the chemical diffusivity. Those diffusion rates are slightly lower than in iron-bearing olivine for the same incorporation mechanism. The different concentration profiles show a clear anisotropy of diffusion, with fastest diffusion parallel to [001] as in iron-bearing olivine. Thus, while hydrogen solubilities are dependent on iron content, the rate of incorporation of water-derived species in olivine is not strongly coupled to the concentration of iron. This

  3. Transformation mapping of the regulatory elements of the ecdysone-inducible P1 gene of Drosophila melanogaster

    SciTech Connect

    Maschat, F.; Dubertret, M.L.; Lepesant, J.A. )

    1991-05-01

    The transcription of the P1 gene is induced by 20-hydroxyecdysone in fat bodies of third-instar larvae. Germ line transformation showed that sequences between {minus}138 to +276 contain elements required for a qualitatively correct developmental and hormonal regulation of P1 transcription. Sequences from {minus}138 to {minus}68 are essential for this expression.

  4. 17 CFR 240.13p-1 - Requirement of report regarding disclosure of registrant's supply chain information regarding...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Requirement of report regarding disclosure of registrant's supply chain information regarding conflict minerals. 240.13p-1 Section 240.13p-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED)...

  5. 17 CFR 240.13p-1 - Requirement of report regarding disclosure of registrant's supply chain information regarding...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Requirement of report regarding disclosure of registrant's supply chain information regarding conflict minerals. 240.13p-1 Section 240.13p-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED)...

  6. Mutational Analysis of the P1 Phosphorylation Domain in Escherichia coli CheA, the Signaling Kinase for Chemotaxis

    PubMed Central

    Nishiyama, So-ichiro; Garzón, Andrés

    2014-01-01

    The histidine autokinase CheA functions as the central processing unit in the Escherichia coli chemotaxis signaling machinery. CheA receives autophosphorylation control inputs from chemoreceptors and in turn regulates the flux of signaling phosphates to the CheY and CheB response regulator proteins. Phospho-CheY changes the direction of flagellar rotation; phospho-CheB covalently modifies receptor molecules during sensory adaptation. The CheA phosphorylation site, His-48, lies in the N-terminal P1 domain, which must engage the CheA ATP-binding domain, P4, to initiate an autophosphorylation reaction cycle. The docking determinants for the P1-P4 interaction have not been experimentally identified. We devised mutant screens to isolate P1 domains with impaired autophosphorylation or phosphotransfer activities. One set of P1 mutants identified amino acid replacements at surface-exposed residues distal to His-48. These lesions reduced the rate of P1 transphosphorylation by P4. However, once phosphorylated, the mutant P1 domains transferred phosphate to CheY at the wild-type rate. Thus, these P1 mutants appear to define interaction determinants for P1-P4 docking during the CheA autophosphorylation reaction. PMID:24163342

  7. Guide tube flow diffuser

    SciTech Connect

    Berringer, R.T.; Myron, D.L.

    1980-11-04

    A nuclear reactor upper internal guide tube has a flow diffuser integral with its bottom end. The guide tube provides guidance for control rods during their ascent or descent from the reactor core. The flow diffuser serves to divert the upward flow of reactor coolant around the outside of the guide tube thereby limiting the amount of coolant flow and turbulence within the guide tube, thus enhancing the ease of movement of the control rods.

  8. Broadband absorption and reduced scattering spectra of in-vivo skin can be noninvasively determined using δ-P1 approximation based spectral analysis

    PubMed Central

    Hung, Cheng-Hung; Chou, Ting-Chun; Hsu, Chao-Kai; Tseng, Sheng-Hao

    2015-01-01

    Previously, we revealed that a linear gradient line source illumination (LGLSI) geometry could work with advanced diffusion models to recover the sample optical properties at wavelengths where sample absorption and reduced scattering were comparable. In this study, we employed the LGLSI geometry with a broadband light source and utilized the spectral analysis to determine the broadband absorption and scattering spectra of turbid samples in the wavelength range from 650 to 1350 nm. The performance of the LGLSI δ-P1 diffusion model based spectral analysis was evaluated using liquid phantoms, and it was found that the sample optical properties could be properly recovered even at wavelengths above 1000 nm where μs' to μa ratios were in the range between 1 to 20. Finally, we will demonstrate the use of our system for recovering the 650 to 1350 nm absorption and scattering spectra of in-vivo human skin. We expect this system can be applied to study deep vessel dilation induced hemoglobin concentration variation and determine the water and lipid concentrations of in-vivo skin in clinical settings in the future. PMID:25780735

  9. Advanced manufacturing: Technology diffusion

    SciTech Connect

    Tesar, A.

    1995-12-01

    In this paper we examine how manufacturing technology diffuses rom the developers of technology across national borders to those who do not have the capability or resources to develop advanced technology on their own. None of the wide variety of technology diffusion mechanisms discussed in this paper are new, yet the opportunities to apply these mechanisms are growing. A dramatic increase in technology diffusion occurred over the last decade. The two major trends which probably drive this increase are a worldwide inclination towards ``freer`` markets and diminishing isolation. Technology is most rapidly diffusing from the US In fact, the US is supplying technology for the rest of the world. The value of the technology supplied by the US more than doubled from 1985 to 1992 (see the Introduction for details). History shows us that technology diffusion is inevitable. It is the rates at which technologies diffuse to other countries which can vary considerably. Manufacturers in these countries are increasingly able to absorb technology. Their manufacturing efficiency is expected to progress as technology becomes increasingly available and utilized.

  10. Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities

    NASA Astrophysics Data System (ADS)

    Chechkin, Aleksei V.; Seno, Flavio; Metzler, Ralf; Sokolov, Igor M.

    2017-04-01

    A growing number of biological, soft, and active matter systems are observed to exhibit normal diffusive dynamics with a linear growth of the mean-squared displacement, yet with a non-Gaussian distribution of increments. Based on the Chubinsky-Slater idea of a diffusing diffusivity, we here establish and analyze a minimal model framework of diffusion processes with fluctuating diffusivity. In particular, we demonstrate the equivalence of the diffusing diffusivity process with a superstatistical approach with a distribution of diffusivities, at times shorter than the diffusivity correlation time. At longer times, a crossover to a Gaussian distribution with an effective diffusivity emerges. Specifically, we establish a subordination picture of Brownian but non-Gaussian diffusion processes, which can be used for a wide class of diffusivity fluctuation statistics. Our results are shown to be in excellent agreement with simulations and numerical evaluations.

  11. Diffusion in natural ilmenite

    NASA Astrophysics Data System (ADS)

    Stenhouse, Iona; O'Neill, Hugh; Lister, Gordon

    2010-05-01

    Diffusion rates in natural ilmenite of composition Fe0.842+ Fe0.163+Mn0.07Mg0.01Ti 0.92O3 from the Vishnevye Mountains (Urals, Russia) have been measured at 1000° C. Experiments were carried out in a one atmosphere furnace with oxygen fugacity controlled by flow of a CO-CO2 gas mixture, over a period of four hours. The diffusant source was a synthetic ilmenite (FeTiO3) powder doped with trace amounts of Mg, Co, Ni, Zr, Hf, V, Nb, Ta, Al, Cr, Ga and Y. Since, the natural ilmenite crystal contained Mn it was also possible to study diffusion of Mn from the ilmenite crystal. The experiments were analysed using the electron microprobe and scanning laser ablation ICP-MS. Diffusion profiles were measured for Al, Mg, Mn, Co, Ni, Ga, and Y. Diffusion of Cr, Hf, Zr, V, Nb and Ta was too slow to allow diffusion profiles to be accurately measured for the times and temperatures studied so far. The preliminary results show that diffusion in ilmenite is fast, with the diffusivity determined in this study on the order of 10-13 to 10-16 m2s-1. For comparison, Chakraborty (1997) found interdiffusion of Fe and Mg in olivine at 1000° C on the order of 10-17 to 10-18m2s-1 and Dieckmann (1998) found diffusivity of Fe, Mg, Co in magnetite at 1200° C to be on the order of 10-13 to 10-14 m2s-1. The order in which the diffusivity of the elements decreases is Mn > Co > Mg ≥ Ni > Al ≥ Y ≥ Ga, that is to say that Mn diffuses the fastest and Ga the slowest. Overall, this study intends to determine diffusion parameters such as frequency factor, activation energy and activation volume as a function of temperature and oxygen fugacity. This research is taking place in the context of a larger study focusing on the use of the garnet-ilmenite system as a geospeedometer. Examination of the consequences of simultaneous diffusion of multiple elements is a necessity if we are to develop an understanding of the crystal-chemical controls on diffusion (cf Spandler & O'Neill, in press). Chakraborty

  12. Involvement of the mannose receptor in the uptake of Der p 1, a major mite allergen, by human dendritic cells.

    PubMed

    Deslée, Gaëtan; Charbonnier, Anne-Sophie; Hammad, Hamida; Angyalosi, Gerhild; Tillie-Leblond, Isabelle; Mantovani, Alberto; Tonnel, André-Bernard; Pestel, Joël

    2002-11-01

    Immature dendritic cells (DCs) take up antigens in peripheral tissues and, after antigen processing, mature to efficiently stimulate T cells in secondary lymph nodes. In allergic airway diseases DCs have been shown to be involved in the induction and maintenance of a T(H)2-type profile. The present study was undertaken to determine pathways of Der p 1 (a house dust mite allergen) uptake by human DCs and to compare Der p 1 uptake between DCs from patients with house dust mite allergy and DCs from healthy donors. Monocyte-derived DCs (MD-DCs) were obtained from patients with house dust mite allergy (n = 13) and healthy donors (n = 11). Der p 1 was labeled with rhodamine. Der p 1 uptake by MD-DCs was analyzed by means of flow cytometry and confocal microscopy. Rhodamine- labeled Der p 1 was demonstrated to be taken up by MD-DCs in a dose-, time-, and temperature- dependent manner. The involvement of the mannose receptor (MR) in the Der p 1 uptake was demonstrated by using (1) inhibitors of the MR- mediated endocytosis (mannan and blocking anti-MR mAb), which inhibited the Der p 1 uptake from 40 % to 50 %, and (2) confocal microscopy showing the colocalization of rhodamine-labeled Der p 1 with FITC-dextran. Interestingly, compared with DCs from healthy donors, DCs from allergic patients expressed more MR and were more efficient in Der p 1 uptake. These results suggest that the MR could play a key role in the Der p 1 allergen uptake by DCs and in the pathogenesis of allergic diseases in dust mite -sensitive patients.

  13. Symptoms and QOL as Predictors of Chemoprevention Adherence in NRG Oncology/NSABP Trial P-1

    PubMed Central

    Walcott, Farzana L.; Liu, Qing; Wickerham, D. Lawrence; Costantino, Joseph P.; Ganz, Patricia A.

    2016-01-01

    Background: Tamoxifen provides a 50% reduction in the incidence of breast cancer (BC) among high-risk women, yet many do not adhere to the five-year course of therapy. Using the prospective double-blind National Surgical Adjuvant Breast and Bowel Project P-1 study, we evaluated whether participant-reported outcomes were associated with drug adherence and whether baseline behavioral risk factors modified those associations. Methods: P-1 participants were randomly assigned to placebo vs tamoxifen (20mg/day). Mixed effects logistic regression was used to evaluate whether baseline or three-month SF-36 quality of life (QOL) mental and physical component summaries (MCS, PCS), and participant-reported symptoms (gynecologic, vasomotor, sexual, and other) predicted 12-month drug adherence (76–100% of assigned medication). The evaluation accounted for age, treatment, estimated breast cancer risk, education, baseline smoking, alcohol consumption, and obesity. All statistical tests were two-sided. Results: Participants enrolled at least three years before trial unblinding and without medically indicated discontinuation before 12 months were eligible for the present analyses (n = 10 576). At 12 months, 84.3% were adherent. Statistically significant predictors of adherence were: three-month MCS (odds ratio [OR] = 1.15 per 10 points, 95% confidence interval [CI] = 1.06 to 1.25); three-month gynecologic symptoms among moderate alcohol drinkers (OR = .79, 95% CI = 0.72 to 0.88); baseline vasomotor symptoms among participants assigned tamoxifen (OR = .88, 95% CI = 0.80 to 0.97); and three-month sexual symptoms among younger participants (OR = .89 at age 41 years, 95% CI = 0.80 to 0.99). The strongest association was with three-month other symptoms (OR = .77, 95% CI = 0.63 to 0.93). PCS was not associated with adherence. Symptom and QOL associations were not modified by smoking or obesity. Conclusions: Promoting QOL and managing symptoms early in therapy may be important strategies

  14. Symptoms and QOL as Predictors of Chemoprevention Adherence in NRG Oncology/NSABP Trial P-1.

    PubMed

    Land, Stephanie R; Walcott, Farzana L; Liu, Qing; Wickerham, D Lawrence; Costantino, Joseph P; Ganz, Patricia A

    2016-04-01

    Tamoxifen provides a 50% reduction in the incidence of breast cancer (BC) among high-risk women, yet many do not adhere to the five-year course of therapy. Using the prospective double-blind National Surgical Adjuvant Breast and Bowel Project P-1 study, we evaluated whether participant-reported outcomes were associated with drug adherence and whether baseline behavioral risk factors modified those associations. P-1 participants were randomly assigned to placebo vs tamoxifen (20mg/day). Mixed effects logistic regression was used to evaluate whether baseline or three-month SF-36 quality of life (QOL) mental and physical component summaries (MCS, PCS), and participant-reported symptoms (gynecologic, vasomotor, sexual, and other) predicted 12-month drug adherence (76-100% of assigned medication). The evaluation accounted for age, treatment, estimated breast cancer risk, education, baseline smoking, alcohol consumption, and obesity. All statistical tests were two-sided. Participants enrolled at least three years before trial unblinding and without medically indicated discontinuation before 12 months were eligible for the present analyses (n = 10 576). At 12 months, 84.3% were adherent. Statistically significant predictors of adherence were: three-month MCS (odds ratio [OR] = 1.15 per 10 points, 95% confidence interval [CI] = 1.06 to 1.25); three-month gynecologic symptoms among moderate alcohol drinkers (OR = .79, 95% CI = 0.72 to 0.88); baseline vasomotor symptoms among participants assigned tamoxifen (OR = .88, 95% CI = 0.80 to 0.97); and three-month sexual symptoms among younger participants (OR = .89 at age 41 years, 95% CI = 0.80 to 0.99). The strongest association was with three-month other symptoms (OR = .77, 95% CI = 0.63 to 0.93). PCS was not associated with adherence. Symptom and QOL associations were not modified by smoking or obesity. Promoting QOL and managing symptoms early in therapy may be important strategies to improve adherence. Published by Oxford

  15. Hypoallergenic Der p 1/Der p 2 combination vaccines for immunotherapy of house dust mite allergy.

    PubMed

    Chen, Kuan-Wei; Blatt, Katharina; Thomas, Wayne R; Swoboda, Ines; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2012-08-01

    More than 50% of allergic patients have house dust mite (HDM) allergy. Group 1 and 2 allergens are the major HDM allergens. We sought to produce and perform preclinical characterization of a recombinant hypoallergenic combination vaccine for specific immunotherapy of HDM allergy. Synthetic genes coding for 2 hybrid proteins consisting of reassembled Der p 1 and Der p 2 fragments with (recombinant Der p 2 [rDer p 2]/1C) and without (rDer p 2/1S) cysteines were expressed in Escherichia coli and purified to homogeneity by means of affinity chromatography. Protein fold was determined by using circular dichroism analysis, allergenic activity was determined by testing IgE reactivity and using basophil activation assays, and the presence of T-cell epitopes was determined based on lymphoproliferation in allergic patients. Mice and rabbits were immunized to study the molecules' ability to induce an allergic response and whether they induce allergen-specific IgG capable of inhibiting allergic patients' IgE binding to the allergens, respectively. rDer p 2/1C and rDer p 2/1S were expressed in large amounts in E coli as soluble and folded proteins. Because of the lack of disulfide bonds, rDer p 2/1S did not form aggregates and was obtained as a monomeric protein, whereas rDer p 2/1C did form aggregates. Both hypoallergens lacked relevant IgE reactivity and had reduced ability to induce allergic inflammation and allergic responses but induced similar T-cell proliferation as the wild-type allergens. Immunization with the hypoallergens (rDer p 2/1S > rDer p 2/1C) induced IgG antibodies in rabbits that inhibited the IgE reactivity of patients with HDM allergy to Der p 1 and Der p 2. The preclinical characterization indicates that particularly rDer p 2/1S can be used as a safe hypoallergenic molecule for both tolerance and vaccination approaches to treat HDM allergy. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  16. Multispecies diffusion models: A study of uranyl species diffusion

    SciTech Connect

    Liu, Chongxuan; Shang, Jianying; Zachara, John M.

    2011-12-14

    Rigorous numerical description of multi-species diffusion requires coupling of species, charge, and aqueous and surface complexation reactions that collectively affect diffusive fluxes. The applicability of a fully coupled diffusion model is, however, often constrained by the availability of species self-diffusion coefficients, as well as by computational complication for imposing charge conservation. In this study, several diffusion models with variable complexity in charge and species coupling were formulated and compared to describe reactive multi-species diffusion in groundwater. Diffusion of uranyl [U(VI)] species was used as an example in demonstrating the effectiveness of the models in describing multi-species diffusion. Numerical simulations found that a diffusion model with a single, common diffusion coefficient for all species was sufficient to describe multi-species U(VI) diffusion under steady-state condition of major chemical composition, but not under transient chemical conditions. Simulations revealed that a fully coupled diffusion model can be well approximated by a component-based diffusion model, which considers difference in diffusion coefficients between chemical components, but not between the species within each chemical component. This treatment significantly enhanced computational efficiency at the expense of minor charge conservation. The charge balance in the component-based diffusion model can be rigorously enforced, if necessary, by adding an artificial kinetic reaction term induced by the charge separation. The diffusion models were applied to describe U(VI) diffusive mass transfer in intragranular domains in two sediments collected from US Department of Energy's Hanford 300A where intragrain diffusion is a rate-limiting process controlling U(VI) adsorption and desorption. The grain-scale reactive diffusion model was able to describe U(VI) adsorption/desorption kinetics that has been described using a semi-empirical, multi-rate model

  17. Pseudogene BMI1P1 expression as a novel predictor for acute myeloid leukemia development and prognosis

    PubMed Central

    Zhou, Ling-Yu; Zhai, Ling-Ling; Yin, Jia-Yu; Vanessa, Minse Evola-Deniz; Zhou, Jiao; Zhang, Jing; Tang, Xi; Lin, Jiang; Qian, Jun; Deng, Zhao-Qun

    2016-01-01

    The BMI1P1 levels of 144 de novo AML patients and 36 healthy donors were detected by real-time quantitative PCR (RQ-PCR). BMI1P1 was significantly down-regulated in AML compared with control (P < 0.001). A receiver operating characteristic (ROC) curve revealed that BMI1P1 expression could differentiate patients with AML from control subjects (AUC = 0.895, 95% CI: 0.835–0.954, P < 0.001). The percentage of blasts in bone marrow (BM) was significantly lower in BMI1P1 high-expressed group versus low-expressed group (P = 0.008). BMI1P1 high-expressed cases had significantly higher complete remission (CR) than BMI1P1 low-expressed cases (P = 0.023). Furthermore, Kaplan–Meier demonstrated that both whole AML cohort and non-M3-AML patients with low BMI1P1 expression showed shorter leukemia free survival (LFS, P = 0.002 and P = 0.01, respectively) and overall survival (OS, P < 0.001 and P = 0.011, respectively) than those with high BMI1P1 expression. Multivariate analysis also showed that BMI1P1 over-expression was an independent favorable prognostic factor for OS in both whole and non-M3 cohort of AML patients (HR = 0.462, 95% CI = 0.243–0.879, P = 0.019 and HR = 0.483, 95% CI = 0.254–0.919, P = 0.027). To further investigate the significance of BMI1P1 expression in the follow-up of AML patients, we monitored the BMI1P1 level in 26 de novo AML patients and found that the BMI1P1 level increased significantly from the initial diagnosis to post-CR (P < 0.001). These results indicated that BMI1P1 might contribute to the diagnosis of AML and the assessment of therapeutic effect. PMID:27329719

  18. 64Cu-Labeled LyP-1-Dendrimer for PET-CT Imaging of Atherosclerotic Plaque

    PubMed Central

    2015-01-01

    The ability to detect and quantify macrophage accumulation can provide important diagnostic and prognostic information for atherosclerotic plaque. We have previously shown that LyP-1, a cyclic 9-amino acid peptide, binds to p32 proteins on activated macrophages, facilitating the visualization of atherosclerotic plaque with PET. Yet, the in vivo plaque accumulation of monomeric [18F]FBA-LyP-1 was low (0.31 ± 0.05%ID/g). To increase the avidity of LyP-1 constructs to p32, we synthesized a dendritic form of LyP-1 on solid phase using lysine as the core structural element. Imaging probes (FAM or 6-BAT) were conjugated to a lysine or cysteine on the dendrimer for optical and PET studies. The N-terminus of the dendrimer was further modified with an aminooxy group in order to conjugate LyP-1 and ARAL peptides bearing a ketone. Oxime ligation of peptides to both dendrimers resulted in (LyP-1)4- and (ARAL)4-dendrimers with optical (FAM) and PET probes (6-BAT). For PET-CT studies, (LyP-1)4- and (ARAL)4-dendrimer-6-BAT were labeled with 64Cu (t1/2 = 12.7 h) and intravenously injected into the atherosclerotic (ApoE–/–) mice. After two hours of circulation, PET-CT coregistered images demonstrated greater uptake of the (LyP-1)4-dendrimer-64Cu than the (ARAL)4-dendrimer-64Cu in the aortic root and descending aorta. Ex vivo images and the biodistribution acquired at three hours after injection also demonstrated a significantly higher uptake of the (LyP-1)4-dendrimer-64Cu (1.1 ± 0.26%ID/g) than the (ARAL)4-dendrimer-64Cu (0.22 ± 0.05%ID/g) in the aorta. Similarly, subcutaneous injection of the LyP-1-dendrimeric carriers resulted in preferential accumulation in plaque-containing regions over 24 h. In the same model system, ex vivo fluorescence images within aortic plaque depict an increased accumulation and penetration of the (LyP-1)4-dendrimer-FAM as compared to the (ARAL)4-dendrimer-FAM. Taken together, the results suggest that the (LyP-1)4-dendrimer can be applied for in

  19. Emotion and hypervigilance: negative affect predicts increased P1 responses to non-negative pictorial stimuli.

    PubMed

    Schomberg, Jessica; Schöne, Benjamin; Gruber, Thomas; Quirin, Markus

    2016-06-01

    Previous research has demonstrated that negative affect influences attentional processes. Here, we investigate whether pre-experimental negative affect predicts a hypervigilant neural response as indicated by increased event-related potential amplitudes in response to neutral and positive visual stimuli. In our study, seventeen male participants filled out the German version of the positive and negative affect schedule (Watson et al. in J Pers Soc Psychol 54:1063-1070, 1988; Krohne et al. in Diagnostica 42:139-156, 1996) and subsequently watched positive (erotica, extreme sports, beautiful women) and neutral (daily activities) photographs while electroencephalogram was recorded. In line with our hypothesis, low state negative affect but not (reduced) positive affect predicted an increase in the first positive event-related potential amplitude P1 as a typical marker of increased selective attention. As this effect occurred in response to non-threatening picture conditions, negative affect may foster an individual's general hypervigilance, a state that has formerly been associated with psychopathology only.

  20. Biochemical characterization of three distinct polygalacturonases from Neosartorya fischeri P1.

    PubMed

    Pan, Xia; Li, Ke; Ma, Rui; Shi, Pengjun; Huang, Huoqing; Yang, Peilong; Meng, Kun; Yao, Bin

    2015-12-01

    Polygalacturonase is one of the most important industrial pectinases. To enrich the genetic resources and develop new enzyme candidates, three polygalacturonase genes (Nfpg I-III) of glycosyl hydrolase family 28 were cloned from Neosartorya fischeri P1 and functionally expressed in Pichia pastoris. The purified recombinant proteins exhibited some distinguished properties. In comparison with other counterparts, NfPG I showed the highest specific activity (40, 123 U/mg), NfPG II had the highest temperature optimum (65 °C), and the pH optimum of NfPG III was the lowest (3.5). The orders of their thermostability and resistance to chemicals tested were NfPG II>NfPG III>NfPG I and NfPG II>NfPG I>NfPG III, respectively. Combinations of these enzymes showed better performance than individuals in the processing and clarification of apple and strawberry juice. These results suggest that N. fischeri polygalacturonases have great application potentials in the food industry for juice production.

  1. Photometric studies of comet C/2009 P1 (Garradd) before the perihelion

    NASA Astrophysics Data System (ADS)

    Ivanova, A. V.; Borisenko, S. A.; Andreev, M. V.

    2014-09-01

    The results of the photometric observations of comet C/2009 P1 (Garradd) performed at the 60-cm Zeiss-600 telescope of the Terskol observatory have been analyzed. During the observations, the comet was at the heliocentric and geocentric distances of 1.7 and 2.0 AU, respectively. The CCD images of the comet were obtained in the standard narrowband interference filters suggested by the International research program for comet Hale-Bopp and correspondingly designated the "Hale-Bopp (HB) set." These filters were designed to isolate the BC ( λ4450/67 Å), GC ( λ5260/56 Å) and RC ( λ7128/58 Å) continua and the emission bands of C2 ( λ5141/118 Å), CN ( λ3870/62 Å), and C3 ( λ4062/62 Å). From the photometric data, the dust production rate of the comet and its color index and color excess were determined. The concentration of C2, CN, and C3 molecules and their production rates along the line of sight were estimated. The obtained results show that the physical parameters of the comet are close to the mean characteristics typical of the dynamically new comets.

  2. The Properties of Sintered Calcium Phosphate with [Ca]/[P] = 1.50

    PubMed Central

    Hung, I-Ming; Shih, Wei-Jen; Hon, Min-Hsiung; Wang, Moo-Chin

    2012-01-01

    In order to obtain the properties of the sintered as-dried calcium phosphate with [Ca]/[P] = 1.50, the characteristics of sintered pellets have been investigated using X-ray diffraction (XRD), inductively coupled plasma-mass spectrometry (ICP-MS), Fourier-transform infrared (FT-IR) spectra, Vickers hardness indentation and scanning electron microscopy (SEM). When the pellet samples were sintered between 700 °C and 1200 °C for 4 h, the hydroxyapatite (Ca10(PO4)6(OH)2, HA) still maintained the major phase, accompanied with the rhenanite (NaCaPO4) as the secondary phase and β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP) as the minor phases. In addition, the HA partially transformed to α-tricalcium phosphate (α-Ca3(PO4)2, α-TCP) and tetracalcium phosphate (Ca4(PO4)2O, TTCP), when the pellet samples were sintered at 1300 °C and 1400 °C, respectively, for 4 h. The maximum density and Vickers Hardness (HV) of sintered pellet samples were 2.85 g/cm3 (90.18% theoretical density (T.D.)) and 407, which appeared at 1200 °C and 900 °C, respectively. PMID:23202968

  3. Mycobacterial p(1)-type ATPases mediate resistance to zinc poisoning in human macrophages.

    PubMed

    Botella, Hélène; Peyron, Pascale; Levillain, Florence; Poincloux, Renaud; Poquet, Yannick; Brandli, Irène; Wang, Chuan; Tailleux, Ludovic; Tilleul, Sylvain; Charrière, Guillaume M; Waddell, Simon J; Foti, Maria; Lugo-Villarino, Geanncarlo; Gao, Qian; Maridonneau-Parini, Isabelle; Butcher, Philip D; Castagnoli, Paola Ricciardi; Gicquel, Brigitte; de Chastellier, Chantal; Neyrolles, Olivier

    2011-09-15

    Mycobacterium tuberculosis thrives within macrophages by residing in phagosomes and preventing them from maturing and fusing with lysosomes. A parallel transcriptional survey of intracellular mycobacteria and their host macrophages revealed signatures of heavy metal poisoning. In particular, mycobacterial genes encoding heavy metal efflux P-type ATPases CtpC, CtpG, and CtpV, and host cell metallothioneins and zinc exporter ZnT1, were induced during infection. Consistent with this pattern of gene modulation, we observed a burst of free zinc inside macrophages, and intraphagosomal zinc accumulation within a few hours postinfection. Zinc exposure led to rapid CtpC induction, and ctpC deficiency caused zinc retention within the mycobacterial cytoplasm, leading to impaired intracellular growth of the bacilli. Thus, the use of P(1)-type ATPases represents a M. tuberculosis strategy to neutralize the toxic effects of zinc in macrophages. We propose that heavy metal toxicity and its counteraction might represent yet another chapter in the host-microbe arms race.

  4. A Novel Thermostable Arylesterase from the Archaeon Sulfolobus solfataricus P1: Purification, Characterization, and Expression▿ †

    PubMed Central

    Park, Young-Jun; Yoon, Sung-Jin; Lee, Hee-Bong

    2008-01-01

    A novel thermostable arylesterase, a 35-kDa monomeric enzyme, was purified from the thermoacidophilic archaeon Sulfolobus solfataricus P1. The optimum temperature and pH were 94°C and 7.0, respectively. The enzyme displayed remarkable thermostability: it retained 52% of its activity after 50 h of incubation at 90°C. In addition, the purified enzyme showed high stability against denaturing agents, including various detergents, urea, and organic solvents. The enzyme has broad substrate specificity besides showing an arylesterase activity toward aromatic esters: it exhibits not only carboxylesterase activity toward tributyrin and p-nitrophenyl esters containing unsubstituted fatty acids from butyrate (C4) to palmitate (C16), but also paraoxonase activity toward organophosphates such as p-nitrophenylphosphate, paraoxon, and methylparaoxon. The kcat/Km ratios of the enzyme for phenyl acetate and paraoxon, the two most preferable substrates among all tested, were 30.6 and 119.4 s−1·μM−1, respectively. The arylesterase gene consists of 918 bp corresponding to 306 amino acid residues. The deduced amino acid sequence shares 34% identity with that of arylesterase from Acinetobacter sp. strain ADP1. Furthermore, we successfully expressed active recombinant S. solfataricus arylesterase in Escherichia coli. Together, our results show that the enzyme is a serine esterase belonging to the A-esterases and contains a catalytic triad composed of Ser156, Asp251, and His281 in the active site. PMID:18931117

  5. Precision measurement of the mass of the hc(1P1) state of charmonium.

    PubMed

    Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Lopez, A; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P

    2008-10-31

    A precision measurement of the mass of the h_{c}(1P1) state of charmonium has been made using a sample of 24.5x10;{6} psi(2S) events produced in e;{+}e;{-} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was psi(2S)-->pi;{0}h_{c}, pi;{0}-->gammagamma, h_{c}-->gammaeta_{c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_{c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_{c})=3525.28+/-0.19(stat.)+/-0.12(syst.) MeV, and B(psi(2S)-->pi;{0}h_{c})xB(h_{c}-->gammaeta_{c})=(4.19+/-0.32+/-0.45)x10;{-4}. Using the ;{3}P_{J} centroid mass, DeltaM_{hf}(1P) identical withM(chi_{cJ})-M(h_{c})=+0.02+/-0.19+/-0.13 MeV.

  6. The evolving activity of the dynamically young comet C/2009 P1 (Garradd)

    SciTech Connect

    Bodewits, D.; Farnham, T. L.; A'Hearn, M. F.; Feaga, L. M.; Sunshine, J. M.; McKay, A.; Schleicher, D. G.

    2014-05-01

    We used the Ultraviolet-Optical Telescope on board Swift to observe the dynamically young comet C/2009 P1 (Garradd) from a heliocentric distance of 3.5 AU pre-perihelion until 4.0 AU outbound. At 3.5 AU pre-perihelion, comet Garradd had one of the highest dust-to-gas ratios ever observed, matched only by comet Hale-Bopp. The evolving morphology of the dust in its coma suggests an outburst that ended around 2.2 AU pre-perihelion. Comparing slit-based measurements and observations acquired with larger fields of view indicated that between 3 AU and 2 AU pre-perihelion a significant extended source started producing water in the coma. We demonstrate that this source, which could be due to icy grains, disappeared quickly around perihelion. Water production by the nucleus may be attributed to a constantly active source of at least 75 km{sup 2}, estimated to be >20% of the surface. Based on our measurements, the comet lost 4 × 10{sup 11} kg of ice and dust during this apparition, corresponding to at most a few meters of its surface. Even though this was likely not the comet's first passage through the inner solar system, the activity of Garradd was complex and changed significantly during the time it was observed.

  7. Precision frequency measurement of 1S0-3P1 intercombination lines of Sr isotopes

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Gao, Feng; Ye-Bing, Wang; Xiao, Tian; Jie, Ren; Ben-Quan, Lu; Qin-Fang, Xu; Yu-Lin, Xie; Hong, Chang

    2015-01-01

    We report on frequency measurement of the intercombination (5s2)1S0-(5s5p)3P1 transition of the four natural isotopes of strontium, including 88Sr (82.58%), 87Sr (7.0%), 86Sr (9.86%), and 84Sr (0.56%). A narrow-linewidth laser that is locked to an ultra-low expansion (ULE) optical cavity with a finesse of 12000 is evaluated at a linewidth of 200 Hz with a fractional frequency drift of 2.8×10-13 at an integration time of 1 s. The fluorescence collector and detector are specially designed, based on a thermal atomic beam. Using a double-pass acousto-optic modulator (AOM) combined with a fiber and laser power stabilization configuration to detune the laser frequency enables high signal-to-noise ratios and precision saturated spectra to be obtained for the six transition lines, which allows us to determine the transition frequency precisely. The optical frequency is measured using an optical frequency synthesizer referenced to an H maser. Both the statistical values and the final values, including the corrections and uncertainties, are derived for a comparison with the values given in other works. Project supported by the National Natural Science Foundation of China (Grant No. 61127901) and the Key Project of the Chinese Academy of Sciences (Grant No. KJZD-EW-W02).

  8. Escape factors for Paschen 2p-1s lines in Ar, Kr, and Xe plasmas

    NASA Astrophysics Data System (ADS)

    Zhu, Xi-Ming; Czarnetzki, Uwe; Cheng, Zhi-Wen; Pu, Yi-Kang

    2016-09-01

    Radiation trapping is often observed when investigating low-temperature plasmas. Photons emitted from an upper state may be reabsorbed by a lower state before they leave the plasmas. To account for this effect, the ``escape factor'' as a function of optical depth is often adopted. In previous works several simple expressions of the escape factor were proposed for uniform plasmas with emission line profiles dominated by Doppler broadening and without line splitting due to hyperfine structure. These assumptions are valid for atoms e.g. Ar in uniform discharges. However, the excited state density in many low-temperature plasmas is non-uniform and the emission line profile can be influenced by collisional broadening. In this work, we study the escape factors of Paschen 2p-1s lines of Ar, Kr, and Xe in non-uniform plasmas. The collisional broadening and the hyperfine structure for Kr and Xe lines are both included. The calculated escape factor expression is verified particularly by an experiment in a low-pressure discharge. The escape factor equation for high- to atmospheric-pressure discharges is also provided.

  9. Time-resolved spectroscopy of the Mercury 6 3P1 state

    NASA Technical Reports Server (NTRS)

    Halstead, J. A.; Reeves, R. R.

    1981-01-01

    The time-resolved fluorescence was observed from the Hg 6 3P1 state under the influence of the earth's magnetic field and with applied fields of up to 14 G. Modulation of the fluorescence decay signal was observed as a function of both time and space and can be interpreted in terms of a classical precession of the excited atom about the magnetic field or as quantum beats resulting from interference between coherently populated Zeeman sublevels. This modulation was studied for each of the five resolvable components of the hyperfine structure separately. The fluorescence from the even isotopes was determined to be almost completely modulated while the fluorescence from the odd isotopes was only partially modulated. The frequency of modulation of the fluorescence from the mercury-202 isotope was observed as a function of the applied magnetic field and a value for the Lande factor of 1.46 + or - 0.03 was obtained. This is within experimental error of the accepted value of 1.486. In addition, the frequency of modulation as a function of applied magnetic field was determined for each of the three resolvable components with more than one contributing isotopic hyperfine line. An investigation of the effect of radiation trapping on the degree modulation was also made.

  10. Experimental investigation of MnFeP1-x As x multilayer active magnetic regenerators

    NASA Astrophysics Data System (ADS)

    Govindappa, P.; Trevizoli, P. V.; Campbell, O.; Niknia, I.; Christiaanse, T. V.; Teyber, R.; Misra, S.; Schwind, M. A.; van Asten, D.; Zhang, L.; Rowe, A.

    2017-08-01

    This paper describes experimental performance data for MnFeP1-x As x multilayer active magnetic regenerators. Five different matrices are tested: (i) one with three layers; (ii) one with six layers; and (iii) three, eight-layer regenerators where the layer thickness is varied. The tests are performed using a dual regenerator bespoke test apparatus based on nested Halbach permanent magnets. (PM II test apparatus at the University of Victoria.) Operating variables include displaced volume (3.8-12.65 cm3), operating frequency (0.5-0.8 Hz) and hot-side rejection temperature (293-313 K). The results are mainly reported in terms of zero net load temperature span as a function of rejection temperature; a few tests with non-zero applied load are also presented. A maximum temperature span of 32 K is found for an eight-layer regenerator, which is similar to a previous work performed with gadolinium in the same experimental apparatus.

  11. Glutathion-S-Transferase P1 polymorphisms association with broncopulmonary dysplasia in preterm infants

    PubMed Central

    Karagianni, P; Rallis, D; Fidani, L; Porpodi, M; Kalinderi, K; Tsakalidis, C; Nikolaidis, N

    2013-01-01

    Background: Oxidative stress, characterized by the excretion of pre-oxidative and anti-oxidative proteases, has a key role in the pathogenesis of bronchopulmonary dysplasia (BPD). One of the many host anti-oxidant enzymes is glutathione-S-transferase P1 (GSTP1), with three polymorphic alleles having been identified: homozygous ile, heterozygous ile/val and homozygous val isomorph. The aim of this study was to examine the genetic predisposition to BPD in the GSTP1 polymorphisms. Methods: A prospective case-control study was carried out in the 2nd Neonatal Intensive Care Unit of Aristotle University in Thessaloniki, Greece during 2008. The genetic polymorphisms of GSTP1 in 28 preterms <32 weeks gestational age (GA) with BPD compared to 74 controls (33 preterms without BPD and 41 healthy terms) were examined. Results: The homozygous ile isomorph was predominant in all groups (preterms with BPD: 82%, preterms without BPD: 70%, healthy terms: 78%), followed by the heterozygous ile/val (14%, 18% and 20% respectively) and the homozygous val isomorph (4%, 12% and 2% respectively). The homozygous ile isomorph was also identified in the majority of preterms with mild (80%), moderate (100%) and severe (73%) BPD. The GSTP1 genetic distribution did not differ between the groups and GSTP1 polymorphisms were not associated with the severity of BPD. Conclusions: This study could not confirm an association between GSTP1 polymorphisms and the development of BPD or the severity of the disease. PMID:25031518

  12. Evaluative conditioning of positive and negative valence affects P1 and N1 in verbal processing.

    PubMed

    Kuchinke, Lars; Fritsch, Nathalie; Müller, Christina J

    2015-10-22

    The present study examined the effect of contextual learning on the neural processing of previously meaningless pseudowords. During an evaluative conditioning session on 5 consecutive days, participants learned to associate 120 pseudowords with either positive, neutral or negative pictures. In a second session, participants were presented all conditioned pseudowords again together with 40 new pseudowords in a recognition memory task while their event-related potentials (ERPs) were recorded. The behavioral data confirm successful learning of pseudoword valence. At the neural level, early modulations of the ERPs are visible at the P1 and the N1 components discriminating between positively and negatively conditioned pseudowords. Differences to new pseudowords were visible at later processing stages as indicated by modulations of the LPC. These results support a contextual learning hypothesis that is able to explain very early emotional ERP modulations in visual word recognition. Source localization indicates a role of medial-frontal brain regions as a likely origin of these early valence discrimination signals which are discussed to promote top-down signals to sensory processing.

  13. The Evolving Activity of the Dynamically Young Comet C/2009 P1 (Garradd)

    NASA Astrophysics Data System (ADS)

    Bodewits, D.; Farnham, T. L.; A'Hearn, M. F.; Feaga, L. M.; McKay, A.; Schleicher, D. G.; Sunshine, J. M.

    2014-05-01

    We used the Ultraviolet-Optical Telescope on board Swift to observe the dynamically young comet C/2009 P1 (Garradd) from a heliocentric distance of 3.5 AU pre-perihelion until 4.0 AU outbound. At 3.5 AU pre-perihelion, comet Garradd had one of the highest dust-to-gas ratios ever observed, matched only by comet Hale-Bopp. The evolving morphology of the dust in its coma suggests an outburst that ended around 2.2 AU pre-perihelion. Comparing slit-based measurements and observations acquired with larger fields of view indicated that between 3 AU and 2 AU pre-perihelion a significant extended source started producing water in the coma. We demonstrate that this source, which could be due to icy grains, disappeared quickly around perihelion. Water production by the nucleus may be attributed to a constantly active source of at least 75 km2, estimated to be >20% of the surface. Based on our measurements, the comet lost 4 × 1011 kg of ice and dust during this apparition, corresponding to at most a few meters of its surface. Even though this was likely not the comet's first passage through the inner solar system, the activity of Garradd was complex and changed significantly during the time it was observed.

  14. Noncommutative Tachyon Kinks as D(p-1)-branes from Unstable Dp-brane

    NASA Astrophysics Data System (ADS)

    Banerjee, Rabin; Kim, Yoonbai; Kwon, O.-Kab

    2005-01-01

    We study noncommutative (NC) field theory of a real NC tachyon and NC U(1) gauge field, describing the dynamics of an unstable Dp-brane. For every given set of diagonal component of open string metric G 0 , NC parameter θ0 , and interpolating electric field hat E, we find all possible static NC kinks as exact solutions, in spite of complicated NC terms, which are classified by an array of NC kink-antikink and topological NC kinks. By computing their tensions and charges, those configurations are identified as an array of D0bar D0 and single stable D0 from the unstable D1, respectively. When the interpolating electric field has critical value as G 0 2 = hat E2 , the obtained topological kink becomes a BPS object with nonzero thickness and is identified as BPS D0 in the fluid of fundamental strings. Particularly in the scaling limit of infinite θ0 and vanishing G 0 and hat E, while keeping G 0θ0 = hat Eθ0 = 1, finiteness of the tension of NC kink corresponds to tensionless kink in ordinary effective field theory. An extension to stable D(p-1) from unstable Dp is straightforward for pure electric cases with parallel NC parameter and interpolating two-form field.

  15. Developmental retardation, microcephaly, and peptiduria in mice without aminopeptidase P1.

    PubMed

    Yoon, Sang Ho; Bae, Young-Soo; Mun, Mi-Sun; Park, Kyeong-Yeol; Ye, Sang-Kyu; Kim, Eunjoon; Kim, Myoung-Hwan

    2012-12-14

    Cytosolic aminopeptidase P1 (APP1) is one of the three known mammalian aminopeptidase Ps (APPs) that cleave the N-terminal amino acid residue of peptides in which the penultimate amino acid is proline. In mammals, many biologically active peptides have a highly conserved N-terminal penultimate proline. However, little is known about the physiological role of APP1. In addition, there is no direct evidence to associate a deficiency in APP1 with metabolic diseases. Although two human subjects with reduced APP activity exhibited peptiduria, it is unclear which of the three APP isoforms is responsible for this disorder. In this study, we generated APP1-deficient mice by knocking out Xpnpep1. Mouse APP1 deficiency causes severe growth retardation, microcephaly, and modest lethality. In addition, imino-oligopeptide excretion was observed in urine samples from APP1-deficient mice. These results suggest an essential role for APP1-mediated peptide metabolism in body and brain development, and indicate a strong causal link between APP1 deficiency and peptiduria.

  16. New Chorus Diffusion Matrix

    NASA Astrophysics Data System (ADS)

    Horne, Richard B.; Kersten, Tobias; Glauert, Sarah A.; Meredith, Nigel P.; Boscher, Daniel; Sicard, Angelica; Maget, Vincent

    2013-04-01

    Whistler mode chorus waves play a major role in the loss and acceleration of electrons in the Earth's radiation belts. While high time resolution satellite data show that these waves are highly structured in frequency and time, at present their effects on the electron distribution can only be assessed on a global scale by using quasi-linear diffusion theory. Here we present new quasi-linear diffusion coefficients for upper and lower band chorus waves for use in global radiation belt models. Using data from DE 1 CRRES, Cluster 1, Double Star TC1 and THEMIS, we have constructed a database of wave properties and used this to construct new diffusion coefficients for L* = 1.5 to 10 in steps of 0.5, 10 latitude bins between 0o and 60o ,8 bins in MLT and 5 levels of geomagnetic activity as measured by Kp. We find that the peak frequency of lower band chorus is close to 0.2 fce, which is lower than that used in previous models. The combined upper and lower band chorus diffusion shows structure that should result in an energy dependent pitch angle anisotropy, particularly between 1 keV and 100 keV. The diffusion rates suggest that wave-particle interactions should still be very important outside geostationary orbit, out to at least L* = 8. We find significant energy diffusion near 1 keV near the loss cone, consistent with wave growth. By including the new chorus diffusion matrix into the BAS radiation belt (BRB) model we compare the effects on the evolution of the radiation belts against previous models.

  17. Effect of interaction with coesite silica on the conformation of Cecropin P1 using explicit solvent molecular dynamics simulation.

    PubMed

    Wu, Xiaoyu; Chang, Hector; Mello, Charlene; Nagarajan, Ramanathan; Narsimhan, Ganesan

    2013-01-28

    Explicit solvent molecular dynamics (MD) simulation was carried out for the antimicrobial peptides (i) Cecropin P1 and C-terminus cysteine modified Cecropin P1 (Cecropin P1 C) in solution, (ii) Cecropin P1 and Cecropin P1 C adsorbed onto coesite -Si - O - and Si - O - H surfaces, and (iii) Cecropin P1 C tethered to coesite -Si - O - surface with either (PEO)(3) or (PEO)(6) linker. Low energy structures for Cecropin P1 and Cecropin P1 C in solution consists of two regions of high α helix probability with a sharp bend, consistent with the available structures of other antimicrobial peptides. The structure of Cecropin P1 C at low ionic strength of 0.02 M exhibits two regions of high α helix probability (residues AKKLEN and EGI) whereas at higher ionic strength of 0.12 M, the molecule was more compact and had three regions of higher α helix probability (residues TAKKLENSA, ISE, and AIQG) with an increase in α helical content from 15.6% to 18.7% as a result of shielding of electrostatic interactions. In the presence of Cecropin P1 C in the vicinity of -Si - O - surface, there is a shift in the location of two peaks in H - O - H density profile to larger distances (2.95 Å and 7.38 Å compared to 2.82 Å and 4.88 Å in the absence of peptide) with attenuated peak intensity. This attenuation is found to be more pronounced for the first peak. H-bond density profile in the vicinity of -Si - O - surface exhibited a single peak in the presence of Cecropin P1 C (at 2.9 Å) which was only slightly different from the profile in the absence of polypeptide (2.82 Å) thus indicating that Cecropin P1 C is not able to break the H-bond formed by the silica surface. The α helix probability for different residues of adsorbed Cecropin P1 C on -Si - O - surface is not significantly different from that of Cecropin P1 C in solution at low ionic strength of 0.02 M whereas there is a decrease in the probability in the second (residues ISE) and third (residues AIQG) α helical regions at

  18. Effect of interaction with coesite silica on the conformation of Cecropin P1 using explicit solvent molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoyu; Chang, Hector; Mello, Charlene; Nagarajan, Ramanathan; Narsimhan, Ganesan

    2013-01-01

    Explicit solvent molecular dynamics (MD) simulation was carried out for the antimicrobial peptides (i) Cecropin P1 and C-terminus cysteine modified Cecropin P1 (Cecropin P1 C) in solution, (ii) Cecropin P1 and Cecropin P1 C adsorbed onto coesite -Si - O - and Si - O - H surfaces, and (iii) Cecropin P1 C tethered to coesite -Si - O - surface with either (PEO)3 or (PEO)6 linker. Low energy structures for Cecropin P1 and Cecropin P1 C in solution consists of two regions of high α helix probability with a sharp bend, consistent with the available structures of other antimicrobial peptides. The structure of Cecropin P1 C at low ionic strength of 0.02 M exhibits two regions of high α helix probability (residues AKKLEN and EGI) whereas at higher ionic strength of 0.12 M, the molecule was more compact and had three regions of higher α helix probability (residues TAKKLENSA, ISE, and AIQG) with an increase in α helical content from 15.6% to 18.7% as a result of shielding of electrostatic interactions. In the presence of Cecropin P1 C in the vicinity of -Si - O - surface, there is a shift in the location of two peaks in H - O - H density profile to larger distances (2.95 Å and 7.38 Å compared to 2.82 Å and 4.88 Å in the absence of peptide) with attenuated peak intensity. This attenuation is found to be more pronounced for the first peak. H-bond density profile in the vicinity of -Si - O - surface exhibited a single peak in the presence of Cecropin P1 C (at 2.9 Å) which was only slightly different from the profile in the absence of polypeptide (2.82 Å) thus indicating that Cecropin P1 C is not able to break the H-bond formed by the silica surface. The α helix probability for different residues of adsorbed Cecropin P1 C on -Si - O - surface is not significantly different from that of Cecropin P1 C in solution at low ionic strength of 0.02 M whereas there is a decrease in the probability in the second (residues ISE) and third (residues AIQG) α helical regions at

  19. CRP represses the CRISPR/Cas system in Escherichia coli: evidence that endogenous CRISPR spacers impede phage P1 replication.

    PubMed

    Yang, Chi-Dung; Chen, Yen-Hua; Huang, Hsi-Yuan; Huang, Hsien-Da; Tseng, Ching-Ping

    2014-06-01

    The CRISPR/Cas system is an important aspect in bacterial immunology. The anti-phage activity of the CRISPR system has been established using synthetic CRISPR spacers, but in vivo studies of endogenous CRISPR spacers are relatively scarce. Here, we showed that bacteriophage P1 titre in Escherichia coli decreased in the glucose-containing medium compared with that in the absence of glucose. This glucose effect of E. coli against phage P1 infection disappeared in cse3 deletion mutants. The effect on the susceptibility to phage P1 was associated with cAMP receptor protein (CRP)-mediated repression of cas genes transcription and crRNA maturation. Analysis of the regulatory element in the cse1 promoter region revealed a novel CRP binding site, which overlapped with a LeuO binding site. Furthermore, the limited sequence identity between endogenous spacers and the phage P1 genome was necessary and sufficient for CRISPR-mediated repression of phage P1 replication. Trans-expression of the third and seventh spacers in the CRISPR I region or third and sixth spacers in the CRISPR II region effectively reduced phage P1 titres in the CRISPR deletion mutants. These results demonstrate a novel regulatory mechanism for cas repression by CRP and provide evidence that endogenous spacers can repress phage P1 replication in E. coli.

  20. Bactericide, Immunomodulating, and Wound Healing Properties of Transgenic Kalanchoe pinnata Synergize with Antimicrobial Peptide Cecropin P1 In Vivo

    PubMed Central

    Lebedeva, A. A.; Zakharchenko, N. S.; Trubnikova, E. V.; Medvedeva, O. A.; Masgutova, G. A.; Zylkova, M. V.; Buryanov, Y. I.; Belous, A. S.

    2017-01-01

    Procedure of manufacturing K. pinnata water extracts containing cecropin P1 (CecP1) from the formerly described transgenic plants is established. It included incubation of leaves at +4°C for 7 days, mechanical homogenization of leaves using water as extraction solvent, and heating at +70°C for inactivating plant enzymes. Yield of CecP1 (after heating and sterilizing filtration) was 0.3% of total protein in the extract. The water extract of K. pinnata + CecP1 exhibits favorable effect on healing of wounds infected with S. aureus (equal to Cefazolin) and with a combination of S. aureus with P. aeruginosa (better than Cefazolin). Wild-type K. pinnata extract exhibited evident microbicide activity against S. aureus with P. aeruginosa but it was substantially strengthened in K. pinnata + CecP1 extract. K. pinnata extracts (both wild-type and transgenic) did not exhibit general toxicity and accelerated wound recovery. Due to immunomodulating activity, wild-type K. pinnata extract accelerated granulation of the wound bed and marginal epithelialization even better than K. pinnata + CecP1 extract. Immunomodulating and microbicide activity of K. pinnata synergizes with microbicide activity of CecP1 accelerating elimination of bacteria. PMID:28326334

  1. Mycobacterium tuberculosis MycP1 protease plays a dual role in regulation of ESX-1 secretion and virulence.

    PubMed

    Ohol, Yamini M; Goetz, David H; Chan, Kaman; Shiloh, Michael U; Craik, Charles S; Cox, Jeffery S

    2010-03-18

    Mycobacterium tuberculosis uses the ESX-1 secretion system to deliver virulence proteins during infection of host cells. Here we report a mechanism of posttranscriptional control of ESX-1 mediated by MycP1, a M. tuberculosis serine protease. We show that MycP1 is required for ESX-1 secretion but that, unexpectedly, genetic inactivation of MycP1 protease activity increases secretion of ESX-1 substrates. We demonstrate that EspB, an ESX-1 substrate required for secretion, is a target of MycP1 in vitro and in vivo. During macrophage infection, an inactive MycP1 protease mutant causes hyperactivation of ESX-1-stimulated innate signaling pathways. MycP1 is required for growth in mice during acute infection, while loss of its protease activity leads to attenuated virulence during chronic infection. As the key ESX-1 substrates ESAT-6 and CFP-10 are highly immunogenic, fine-tuning of their secretion by MycP1 may balance virulence and immune detection and be essential for successful maintenance of long-term M. tuberculosis infection.

  2. P1-independent replication and local movement of Rice yellow mottle virus in host and non-host plant species.

    PubMed

    Nummert, Grete; Sõmera, Merike; Uffert, Gabriela; Abner, Erik; Truve, Erkki

    2017-02-01

    Sobemovirus P1 protein, characterized previously as a suppressor of posttranscriptional gene silencing, is required for systemic virus spread and infection in plants. Mutations in the ORF1 initiation codon do not affect viral replication indicating P1 is not necessary for this process. Wild type, recombinant and P1 deletion mutants of Cocksfoot mottle virus and Rice yellow mottle virus were used to infect oat, rice, wheat, barley, Arabidopsis thaliana and Nicotiana benthamiana plants. Wild type RYMV, RYMV without P1 and RYMV with CfMV P1 were detected in inoculated leaves of all tested plant species. We found that RYMV does not need P1 for replication and for local movement neither in host nor non-host species tested in this study. However, it is crucial for successful systemic spread of the virus in its host plant rice. Moreover, adding CfMV P1 into RYMV genome did not help it to overcome restriction to the inoculated leaf. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Immunomodulating and Revascularizing Activity of Kalanchoe pinnata Synergize with Fungicide Activity of Biogenic Peptide Cecropin P1.

    PubMed

    Zakharchenko, N S; Belous, A S; Biryukova, Y K; Medvedeva, O A; Belyakova, A V; Masgutova, G A; Trubnikova, E V; Buryanov, Y I; Lebedeva, A A

    2017-01-01

    Previously transgenic Kalanchoe pinnata plants producing an antimicrobial peptide cecropin P1 (CecP1) have been reported. Now we report biological testing K. pinnata extracts containing CecP1 as a candidate drug for treatment of wounds infected with Candida albicans. The drug constitutes the whole juice from K. pinnata leaves (not ethanol extract) sterilized with nanofiltration. A microbicide activity of CecP1 against an animal fungal pathogen in vivo was demonstrated for the first time. However, a favorable therapeutic effect of the transgenic K. pinnata extract was attributed to a synergism between the fungicide activity of CecP1 and wound healing (antiscar), revascularizing, and immunomodulating effect of natural biologically active components of K. pinnata. A commercial fungicide preparation clotrimazole eliminated C. albicans cells within infected wounds in rats with efficiency comparable to CecP1-enriched K. pinnata extract. But in contrast to K. pinnata extract, clotrimazole did not exhibit neither wound healing activity nor remodeling of the scar matrix. Taken together, our results allow assumption that CecP1-enriched K. pinnata extracts should be considered as a candidate drug for treatment of dermatomycoses, wounds infected with fungi, and bedsores.

  4. Immunomodulating and Revascularizing Activity of Kalanchoe pinnata Synergize with Fungicide Activity of Biogenic Peptide Cecropin P1

    PubMed Central

    Zakharchenko, N. S.; Belous, A. S.; Medvedeva, O. A.; Belyakova, A. V.; Masgutova, G. A.; Trubnikova, E. V.; Buryanov, Y. I.; Lebedeva, A. A.

    2017-01-01

    Previously transgenic Kalanchoe pinnata plants producing an antimicrobial peptide cecropin P1 (CecP1) have been reported. Now we report biological testing K. pinnata extracts containing CecP1 as a candidate drug for treatment of wounds infected with Candida albicans. The drug constitutes the whole juice from K. pinnata leaves (not ethanol extract) sterilized with nanofiltration. A microbicide activity of CecP1 against an animal fungal pathogen in vivo was demonstrated for the first time. However, a favorable therapeutic effect of the transgenic K. pinnata extract was attributed to a synergism between the fungicide activity of CecP1 and wound healing (antiscar), revascularizing, and immunomodulating effect of natural biologically active components of K. pinnata. A commercial fungicide preparation clotrimazole eliminated C. albicans cells within infected wounds in rats with efficiency comparable to CecP1-enriched K. pinnata extract. But in contrast to K. pinnata extract, clotrimazole did not exhibit neither wound healing activity nor remodeling of the scar matrix. Taken together, our results allow assumption that CecP1-enriched K. pinnata extracts should be considered as a candidate drug for treatment of dermatomycoses, wounds infected with fungi, and bedsores. PMID:28695135

  5. Bactericide, Immunomodulating, and Wound Healing Properties of Transgenic Kalanchoe pinnata Synergize with Antimicrobial Peptide Cecropin P1 In Vivo.

    PubMed

    Lebedeva, A A; Zakharchenko, N S; Trubnikova, E V; Medvedeva, O A; Kuznetsova, T V; Masgutova, G A; Zylkova, M V; Buryanov, Y I; Belous, A S

    2017-01-01

    Procedure of manufacturing K. pinnata water extracts containing cecropin P1 (CecP1) from the formerly described transgenic plants is established. It included incubation of leaves at +4°C for 7 days, mechanical homogenization of leaves using water as extraction solvent, and heating at +70°C for inactivating plant enzymes. Yield of CecP1 (after heating and sterilizing filtration) was 0.3% of total protein in the extract. The water extract of K. pinnata + CecP1 exhibits favorable effect on healing of wounds infected with S. aureus (equal to Cefazolin) and with a combination of S. aureus with P. aeruginosa (better than Cefazolin). Wild-type K. pinnata extract exhibited evident microbicide activity against S. aureus with P. aeruginosa but it was substantially strengthened in K. pinnata + CecP1 extract. K. pinnata extracts (both wild-type and transgenic) did not exhibit general toxicity and accelerated wound recovery. Due to immunomodulating activity, wild-type K. pinnata extract accelerated granulation of the wound bed and marginal epithelialization even better than K. pinnata + CecP1 extract. Immunomodulating and microbicide activity of K. pinnata synergizes with microbicide activity of CecP1 accelerating elimination of bacteria.

  6. In planta expression of a mature Der p 1 allergen isolated from an Italian strain of Dermatophagoides pteronyssinus.

    PubMed

    Marconi, Gianpiero; Albertini, Emidio; Mari, Adriano; Palazzo, Paola; Porceddu, Andrea; Raggi, Lorenzo; Bolis, Luigi; Lancioni, Hovirag; Palomba, Antonella; Lucentini, Livia; Lanfaloni, Luisa; Marcucci, Francesco; Falcinelli, Mario; Panara, Fausto

    2012-06-01

    European (Dermatophagoides pteronyssinus) and American (Dermatophagoides farinae) house dust mite species are considered the most common causes of asthma and allergic symptoms worldwide. Der p 1 protein, one of the main allergens of D. pteronyssinus, is found in high concentration in mites faecal pellets, which can became easily airborne and, when inhaled, can cause perennial rhinitis and bronchial asthma. Here we report the isolation of the Der p 1 gene from an Italian strain of D. pteronyssinus and the PVX-mediated expression of its mature form (I-rDer p 1) in Nicotiana benthamiana plants. Human sera from characterized allergic patients were used for IgE binding inhibition assays to test the immunological reactivity of I-rDer p 1 produced in N. benthamiana plants. The binding properties of in planta produced I-rDer p 1 versus the IgE of patients sera were comparable to those obtained on Der p 1 preparation immobilized on a microarray. In this paper we provide a proof of concept for the production of an immunologically active form of Der p 1 using a plant viral vector. These results pave the way for the development of diagnostic allergy tests based on in planta produced allergens.

  7. Comparative genomics of pAKD4, the prototype IncP-1δplasmid with a complete backbone

    PubMed Central

    Sen, Diya; Yano, Hirokazu; Suzuki, Haruo; Król, Jaroslaw E.; Rogers, Linda; Brown, Celeste J.; Top, Eva M.

    2010-01-01

    Plasmids of the incompatibility group IncP-1 are important agents of horizontal gene transfer and contribute to the spread of antibiotic resistance and xenobiotic degradation within bacterial communities. Even though some prototype plasmids have been studied in much detail, the diversity of this plasmid group was still greatly underestimated until recently, as only two of the five currently known divergent sub-groups had been described. To further improve our insight into the diversity and evolutionary history of this family of broad-host-range plasmids, we compared the complete nucleotide sequence of a new IncP-1δ plasmid pAKD4 to the genomes of other IncP-1 plasmids. Plasmid pAKD4 was previously isolated by exogenous plasmid isolation from an agricultural soil in Norway. Its 56,803 bp nucleotide sequence shows high similarity in gene sequence and gene order to both plasmids pEST4011 and pIJB1, the only other IncP-1δ plasmids sequenced so far. While all three plasmids have a typical IncP-1 backbone comprising replication, transfer and stable inheritance/control genes, the low sequence similarity in some regions and presence/absence of some backbone genes compared to other IncP-1 plasmids cluster them in a divergent sub-group. Therefore this study validates the presence of a real IncP-1δ clade with multiple plasmids. Moreover, since both pEST4011 and pIJB1 are missing a portion of their transfer genes, pAKD4 represents the first completely sequenced self-transferable plasmid with a complete IncP-1δ backbone. We therefore propose it to be the prototype IncP-1δ plasmid. PMID:20018208

  8. Effect of the house dust mite allergen Der p 1 on tryptase release from human mast cells.

    PubMed

    Wang, D Q; Shen, Y Y; Xu, J H; Tang, H

    2016-07-14

    This study aimed to investigate the effects of the house dust mite allergen Der p 1 on the secretion of tryptase from the human mast cell line HMC-1. Flow cytometry was used to determine the expression levels of protease-activated receptor-2 (PAR2) on the surface of HMC-1 cells. HMC-1 cells were treated with Der p 1, SLIGRL-NH2 (PAR2 agonist), LRGILS-NH2 (control peptide for PAR2), or Der p 1 + FSLLRY (PAR2 antagonist), and the tryptase levels were measured using enzyme-linked immunosorbent assay. The biological functions of PAR2 were determined using the calcium green indicator, and intracellular calcium fluorescence intensity in the different groups (Der p 1, SLIGRL-NH2, LRGILS- NH2, Der p 1 + FSLLRY, tryptase, tryptase + FSLLRY, or cell culture medium) was detected by laser scanning confocal microscopy. The mast cells expressed PAR2 receptor on their surfaces. Der p 1 alone induced a significant release of intracellular calcium and tryptase in HMC-1 cells compared with the SLIGRL- NH2 treatment group and the control group. The combination of Der p 1 and FSLLRY partly inhibited intracellular calcium and tryptase release in HMC-1 cells compared with the Der p 1 treatment group. Moreover, tryptase induced a significant release of intracellular calcium in the HMC-1 cells. Der p 1 induced HMC-1 cell degranulation and the release of tryptase by activating the PAR2 receptor on the cell surfaces. Tryptase activated the PAR2 receptor and induced intracellular calcium release from the HMC-1 cells in a positive feedback loop.

  9. Diffuser for wellhead isolation tool

    SciTech Connect

    Surjaatmadja, J.B.

    1981-04-21

    An improved diffuser for a wellhead isolation tool which employs a combination of angles in its bore. This improvement reduces the incidence of erosion caused by the flow of fluids through the diffuser, in both the well production tubing adjacent the end of the diffuser and in the diffuser itself.

  10. Multidimensional diffusion MRI

    NASA Astrophysics Data System (ADS)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  11. Bicarbonate diffusion through mucus.

    PubMed

    Livingston, E H; Miller, J; Engel, E

    1995-09-01

    The mucus layer overlying duodenal epithelium maintains a pH gradient against high luminal acid concentrations. Despite these adverse conditions, epithelial surface pH remains close to neutrality. The exact nature of the gradient-forming barrier remains unknown. The barrier consists of mucus into which HCO3- is secreted. Quantification of the ability of HCO3- to establish and maintain the gradient depends on accurate measurement of this ion's diffusion coefficient through mucus. We describe new experimental and mathematical methods for diffusion measurement and report diffusion coefficients for HCO3- diffusion through saline, 5% mucin solutions, and rat duodenal mucus. The diffusion coefficients were 20.2 +/- 0.10, 3.02 +/- 0.31, and 1.81 +/- 0.12 x 10(-6) cm2/s, respectively. Modeling of the mucobicarbonate layer with this latter value suggests that for conditions of high luminal acid strength the neutralization of acid by HCO3- occurs just above the epithelial surface. Under these conditions the model predicts that fluid convection toward the lumen could be important in maintaining the pH gradient. In support of this hypothesis we were able to demonstrate a net luminal fluid flux of 5 microliters.min-1.cm-2 after perfusion of 0.15 N HCl in the rat duodenum.

  12. Diffusion Influenced Adsorption Kinetics.

    PubMed

    Miura, Toshiaki; Seki, Kazuhiko

    2015-08-27

    When the kinetics of adsorption is influenced by the diffusive flow of solutes, the solute concentration at the surface is influenced by the surface coverage of solutes, which is given by the Langmuir-Hinshelwood adsorption equation. The diffusion equation with the boundary condition given by the Langmuir-Hinshelwood adsorption equation leads to the nonlinear integro-differential equation for the surface coverage. In this paper, we solved the nonlinear integro-differential equation using the Grünwald-Letnikov formula developed to solve fractional kinetics. Guided by the numerical results, analytical expressions for the upper and lower bounds of the exact numerical results were obtained. The upper and lower bounds were close to the exact numerical results in the diffusion- and reaction-controlled limits, respectively. We examined the validity of the two simple analytical expressions obtained in the diffusion-controlled limit. The results were generalized to include the effect of dispersive diffusion. We also investigated the effect of molecular rearrangement of anisotropic molecules on surface coverage.

  13. Expression of flavonoid 3’-hydroxylase is controlled by P1, the regulator of 3-deoxyflavonoid biosynthesis in maize

    PubMed Central

    2012-01-01

    Background The maize (Zea mays) red aleurone1 (pr1) encodes a CYP450-dependent flavonoid 3’-hydroxylase (ZmF3’H1) required for the biosynthesis of purple and red anthocyanin pigments. We previously showed that Zmf3’h1 is regulated by C1 (Colorless1) and R1 (Red1) transcription factors. The current study demonstrates that, in addition to its role in anthocyanin biosynthesis, the Zmf3’h1 gene also participates in the biosynthesis of 3-deoxyflavonoids and phlobaphenes that accumulate in maize pericarps, cob glumes, and silks. Biosynthesis of 3-deoxyflavonoids is regulated by P1 (Pericarp color1) and is independent from the action of C1 and R1 transcription factors. Results In maize, apiforol and luteoforol are the precursors of condensed phlobaphenes. Maize lines with functional alleles of pr1 and p1 (Pr1;P1) accumulate luteoforol, while null pr1 lines with a functional or non-functional p1 allele (pr1;P1 or pr1;p1) accumulate apiforol. Apiforol lacks a hydroxyl group at the 3’-position of the flavylium B-ring, while luteoforol has this hydroxyl group. Our biochemical analysis of accumulated compounds in different pr1 genotypes showed that the pr1 encoded ZmF3’H1 has a role in the conversion of mono-hydroxylated to bi-hydroxylated compounds in the B-ring. Steady state RNA analyses demonstrated that Zmf3’h1 mRNA accumulation requires a functional p1 allele. Using a combination of EMSA and ChIP experiments, we established that the Zmf3’h1 gene is a direct target of P1. Highlighting the significance of the Zmf3’h1 gene for resistance against biotic stress, we also show here that the p1 controlled 3-deoxyanthocyanidin and C-glycosyl flavone (maysin) defence compounds accumulate at significantly higher levels in Pr1 silks as compared to pr1 silks. By virtue of increased maysin synthesis in Pr1 plants, corn ear worm larvae fed on Pr1; P1 silks showed slower growth as compared to pr1; P1 silks. Conclusions Our results show that the Zmf3’h1 gene

  14. Growth kinetics of a single InP1-xAsx nanowire

    NASA Astrophysics Data System (ADS)

    Harmand, Jean-Christophe; Glas, Frank; Patriarche, Gilles

    2010-06-01

    Semiconductor nanowires offer additional properties and more flexibility for many potential applications. However the precise control of their growth is very challenging and much more complex than for two-dimensional layers. Here, we present a method which provides detailed information on their formation. The method is implemented with In(P,As) nanowires grown by Au-catalyzed molecular beam epitaxy. Controlled and periodic modulations of the incident vapor phase are generated. Due to these modulations, the nanowires show small and short oscillations of composition along their growth axis. These oscillations furnish a time scale which is recorded in the nanowire solid phase. The instantaneous growth rate and the total length of the nanowire at any time of the growth are accessible. The experimental data are fitted with models. The adatom diffusion lengths on the different surfaces and the chemical potentials in the adsorbed and liquid phases are extracted. It appears that the vapor flux intercepted by the nanowire sidewalls is the dominant contribution to their elongation. We discuss which contribution allows one initiating their growth from the catalyst drop.

  15. Characteristics of nitrogen release from synthetic zeolite Na-P1 occluding NH4NO3.

    PubMed

    Park, Man; Kim, Jong Su; Choi, Choong Lyeal; Kim, Jang-Eok; Heo, Nam Ho; Komarneni, Sridhar; Choi, Jyung

    2005-08-18

    Zeolites can accommodate a considerable amount of occluded salt such as NH4NO3, which can serve as a good source of slow-release plant nutrient. This study evaluates the kinetics of ion release from NH4NO3-occluded Na-P1 (N-NaP) using a simulated soil solution and deionized water as leaching solutions. The patterns of ion releases were examined as a function of leaching time under both static and continuous-flow conditions for more than one month. Releases of both NH4+ and NO3- from N-NaP were found to be slow and steady under both the above conditions. The soil solution affected the release of NH4+ and NO3- differently, while deionized water released nearly the same equivalents of these ions. This clearly indicates that ion release from salt-occluded zeolite involves two different reactions, cation exchange and dissolution. The kinetics of ion release from occluded NH4NO3 under static condition was best described by the standard Elovich model while the power function model best expressed these under continuous-flow condition. The initial ion release patterns under both conditions exhibited considerable deviation from the simulated models, probably as a result of the presence of hydrated occluded NH4NO3. Flow condition and the presence of electrolytes in leaching solution affected the release kinetics significantly. Release of occluded NH4NO3 was delayed by the presence of the NH4NO3 coated on zeolite crystals. These results indicate that the ion release property of occluded salt could be predicted and controlled. This study clearly shows that NH4NO3-occluded zeolites could be developed as slow release fertilizers.

  16. Spatial structure and nutrients promote invasion of IncP-1 plasmids in bacterial populations

    PubMed Central

    Fox, Randal E; Zhong, Xue; Krone, Stephen M; Top, Eva M

    2008-01-01

    In spite of the importance of plasmids in bacterial adaptation, we have a poor understanding of their dynamics. It is not known if or how plasmids persist in and spread through (invade) a bacterial population when there is no selection for plasmid-encoded traits. Moreover, the differences in dynamics between spatially structured and mixed populations are poorly understood. Through a joint experimental/theoretical approach, we tested the hypothesis that self-transmissible IncP-1 plasmids can invade a bacterial population in the absence of selection when initially very rare, but only in spatially structured habitats and when nutrients are regularly replenished. Using protocols that differed in the degree of spatial structure and nutrient levels, the invasiveness of plasmid pB10 in Escherichia coli was monitored during at least 15 days, with an initial fraction of plasmid-bearing (p+) cells as low as 10−7. To further explore the mechanisms underlying plasmid dynamics, we developed a spatially explicit mathematical model. When cells were grown on filters and transferred to fresh medium daily, the p+ fraction increased to 13%, whereas almost complete invasion occurred when the population structure was disturbed daily. The plasmid was unable to invade in liquid. When carbon source levels were lower or not replenished, plasmid invasion was hampered. Simulations of the mathematical model closely matched the experimental results and produced estimates of the effects of alternative experimental parameters. This allowed us to isolate the likely mechanisms most responsible for the observations. In conclusion, spatial structure and nutrient availability can be key determinants in the invasiveness of plasmids. PMID:18528415

  17. Uncorrelated volatile behavior during the 2011 apparition of comet C/2009 P1 Garradd

    SciTech Connect

    Feaga, Lori M.; A'Hearn, Michael F.; Farnham, Tony L.; Bodewits, Dennis; Sunshine, Jessica M.; Gersch, Alan M.; Protopapa, Silvia; Yang, Bin; Drahus, Michal; Schleicher, David G.

    2014-01-01

    The High Resolution Instrument Infrared Spectrometer (HRI-IR) on board the Deep Impact Flyby spacecraft detected H{sub 2}O, CO{sub 2}, and CO in the coma of the dynamically young Oort Cloud comet C/2009 P1 (Garradd) post-perihelion at a heliocentric distance of 2 AU. Production rates were derived for the parent volatiles, Q {sub H2O} = 4.6 ± 0.8 × 10{sup 28}, Q {sub CO2} = 3.9 ± 0.7 × 10{sup 27}, and Q {sub CO} = 2.9 ± 0.8 × 10{sup 28} molecules s{sup –1}, and are consistent with the trends seen by other observers and within the error bars of measurements acquired during a similar time period. When compiled with other observations of Garradd's dominant volatiles, unexpected behavior was seen in the release of CO. Garradd's H{sub 2}O outgassing, increasing and peaking pre-perihelion and then steadily decreasing, is more typical than that of CO, which monotonically increased throughout the entire apparition. Due to the temporal asymmetry in volatile release, Garradd exhibited the highest CO to H{sub 2}O abundance ratio ever observed for any comet inside the water snow line at ∼60% during the HRI-IR observations. Also, the HRI-IR made the only direct measurement of CO{sub 2}, giving a typical cometary abundance ratio of CO{sub 2} to H{sub 2}O of 8% but, with only one measurement, no sense of how it varied with orbital position.

  18. The evolving activity of the Dynamically Young Comet C/2009 P1 (Garradd)

    NASA Astrophysics Data System (ADS)

    Bodewits, Dennis; Farnham, T. L.; A'Hearn, M. F.; Feaga, L. M.; McKay, A.; Schleicher, D. G.; Sunshine, J.

    2013-10-01

    Comet C/2009 P1 (Garradd) was a dynamically young comet that was bright and well-observable from a heliocentric distance of 3.5 AU pre-perihelion until 4.5 AU outbound. The development of its activity was observed by many different observatories and instruments, both on the ground and in space (Deep Impact, Swift, SOHO-SWAN, VLT-UVES, IRTF, and many more). Because of this observing campaign, Garradd is the first comet for which production rates of all three main volatiles (H2O, CO, and CO2) were measured during a significant part of its passage through the inner solar system. These observations provide an invaluable key to how comets work. At -3.5 AU, Garradd had one of the highest dust-to-gas ratios ever observed, matched only by Hale-Bopp. Comparing slit-based measurements and observations acquired with larger fields of view indicated that between -3 AU and -2 AU a significant extended source started producing water in the coma (Combi et al. 2013, Paganini et al. 2012, Villanueva et al. 2012). This source, likely icy grains, disappeared quickly around perihelion (Bodewits et al. in prep.). The other volatiles observed in Garradd’s coma indicate an even more complex story. Relative abundances measured with large apertures were lowered significantly by the extended water source, indicating that these icy grains were depleted of ices more volatile than water. Differences in the volatility of cometary ices may further explain the observed trends in the abundances of CN and CO2 (mostly observed through [OI]; Decock et al. 2013). These effects do not explain the strange behavior of CO, whose production rate increased monotonically from -2 AU to +2AU (Feaga et al. submitted, and references therein). The activity of Garradd was complex and changed significantly during the time it was observed. We will discuss how these different sublimation processes fit into our understanding of cometary activity and evolution in general.

  19. The Water Production Rate of Comet 2009 P1 (Garradd) throughout the 2011-2012 Apparition

    NASA Astrophysics Data System (ADS)

    Combi, Michael R.; Mäkinen, J. T. T.; Bertaux, J.; Quémerais, E.; Ferron, S.

    2012-10-01

    The all-sky hydrogen Lyman-alpha camera, SWAN (Solar Wind Anisotropies), on the SOlar and Heliospheric Observatory (SOHO) satellite made observations of the hydrogen coma of comet 2009 P1 (Garradd) throughout its apparition from August 15, 2011 through April 6, 2012. SOHO has been operating in a halo orbit around the Earth-Sun L1 Lagrange point since its launch in late 1995. Most water vapor produced by the comet is ultimately photodissociated into two H atoms and one O atom producing a huge atomic hydrogen coma that is routinely observed in the daily full-sky SWAN images in comets of sufficient brightness. Water production rates were calculated from 117 images over 8 months of the apparition using our time-resolved model (Mäkinen & Combi, 2005, Icarus 177, 217), yielding about 1 observation every 2 days on the average. The activity during much of the pre-perihelion leg was dominated by likely seasonal variability rather than a consistent increasing trend with decreasing heliocentric distance and varied between 1 and 3 x 1029 s-1. A single peak value for the water production rate (4 x 1029 s-1) was found on November 3, 2011, 50 days before perihelion. On the other hand during the post-perihelion leg the production rate decreased rather consistently from 2 x 1029 s-1at perihelion, approximately as r-4.6, where r is the heliocentric distance. The overall shape of the variation with time over the apparition shows many of the same general features as the visual light curve of Yoshida (http://www.aerith.net/comet/catalog/index-T-earth.html). SOHO is an international cooperative mission between ESA and NASA. Support from grant NNX11AH50G from the NASA Planetary Astronomy Program is also acknowledged.

  20. Broad-host-range IncP-1 plasmids and their resistance potential

    PubMed Central

    Popowska, Magdalena; Krawczyk-Balska, Agata

    2013-01-01

    The plasmids of the incompatibility (Inc) group IncP-1, also called IncP, as extrachromosomal genetic elements can transfer and replicate virtually in all Gram-negative bacteria. They are composed of backbone genes that encode a variety of essential functions and accessory genes that have implications for human health and environmental bioremediation. Broad-host-range IncP plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to a broad spectrum of antibiotics, heavy metals, and quaternary ammonium compounds used as disinfectants. The backbone of these plasmids carries modules that enable them to effectively replicate, move to a new host via conjugative transfer and to be stably maintained in bacterial cells. The adaptive, resistance, and virulence genes are mainly located on mobile genetic elements integrated between the functional plasmid backbone modules. Environmental studies have demonstrated the wide distribution of IncP-like replicons in manure, soils and wastewater treatment plants. They also are present in strains of pathogenic or opportunistic bacteria, which can be a cause for concern, because they may encode multiresistance. Their broad distribution suggests that IncP plasmids play a crucial role in bacterial adaptation by utilizing horizontal gene transfer. This review summarizes the variety of genetic information and physiological functions carried by IncP plasmids, which can contribute to the spread of antibiotic and heavy metal resistance while also mediating the process of bioremediation of pollutants. Due to the location of the resistance genes on plasmids with a broad-host-range and the presence of transposons carrying these genes it seems that the spread of these genes would be possible and quite hazardous in infection control. Future studies are required to determine the level of risk of the spread of resistance genes located on these plasmids. PMID:23471189

  1. Apparatus for diffusion separation

    DOEpatents

    Nierenberg, William A.; Pontius, Rex B.

    1976-08-10

    1. The method of testing the separation efficiency of porous permeable membranes which comprises causing a stream of a gaseous mixture to flow into contact with one face of a finely porous permeable membrane under such conditions that a major fraction of the mixture diffuses through the membrane, maintaining a rectangular cross section of the gaseous stream so flowing past said membrane, continuously recirculating the gas that diffuses through said membrane and continuously withdrawing the gas that does not diffuse through said membrane and maintaining the volume of said recirculating gas constant by continuously introducing into said continuously recirculating gas stream a mass of gas equivalent to that which is continuously withdrawn from said gas stream and comparing the concentrations of the light component in the entering gas, the withdrawn gas and the recirculated gas in order to determine the efficiency of said membrane.

  2. Memory-controlled diffusion

    NASA Astrophysics Data System (ADS)

    Trimper, Steffen; Zabrocki, Knud; Schulz, Michael

    2004-11-01

    Memory effects require for their incorporation into random-walk models an extension of the conventional equations. The linear Fokker-Planck equation for the probability density p(r⃗,t) is generalized by including nonlinear and nonlocal spatial-temporal memory effects. The realization of the memory kernel is restricted due the conservation of the basic quantity p . A general criteria is given for the existence of stationary solutions. In case the memory kernel depends on p polynomially, transport may be prevented. Owing to the delay effects a finite amount of particles remains localized and the further transport is terminated. For diffusion with nonlinear memory effects we find an exact solution in the long-time limit. Although the mean square displacement exhibits diffusive behavior, higher order cumulants offer differences to diffusion and they depend on the memory strength.

  3. Cesium diffusion in graphite

    SciTech Connect

    Evans, R.B. III; Davis, W. Jr.; Sutton, A.L. Jr.

    1980-05-01

    Experiments on diffusion of /sup 137/Cs in five types of graphite were performed. The document provides a completion of the report that was started and includes a presentation of all of the diffusion data, previously unpublished. Except for data on mass transfer of /sup 137/Cs in the Hawker-Siddeley graphite, analyses of experimental results were initiated but not completed. The mass transfer process of cesium in HS-1-1 graphite at 600 to 1000/sup 0/C in a helium atmosphere is essentially pure diffusion wherein values of (E/epsilon) and ..delta..E of the equation D/epsilon = (D/epsilon)/sub 0/ exp (-..delta..E/RT) are about 4 x 10/sup -2/ cm/sup 2//s and 30 kcal/mole, respectively.

  4. Positron diffusion in Si

    SciTech Connect

    Nielsen, B.; Lynn, K.G.; Vehanen, A.; Schultz, P.J.

    1985-06-01

    Positron diffusion in Si(100) and Si(111) has been studied using a variable energy positron beam. The positron diffusion coefficient is found to be D/sub +/ = 2.7 +- 0.3 cm/sup 2//sec using a Makhov-type positron implantation profile, which is demonstrated to fit the data more reliably than the more commonly applied exponential profile. The diffusion related parameter, E/sub 0/, which results from the exponential profile, is found to be 4.2 +- 0.2 keV, significantly longer than previously reported values. A drastic reduction in E/sub 0/ is found after annealing the sample at 1300 K, showing that previously reported low values of E/sub 0/ are probably associated with the thermal history of the sample.

  5. Transverse Spin Diffusion

    NASA Astrophysics Data System (ADS)

    Mullin, William

    2014-05-01

    Transverse spin diffusion is a relatively new transport coefficient and a review of its history and physical basis will be presented. In NMR spin diffusion is often measured by spin echo techniques, which involve spin currents perpendicular to the direction of the magnetization, in contrast with the usual longitudinal case where the current is parallel to the magnetization. The first indication that this involved new physics was the Leggett-Rice effect (1970) in which spin waves, new spin-echo behavior, and an altered spin diffusion coefficient were predicted in liquid 3He. This effect gave the possibility of the first measurement of F1a, the parameter of the Landau Fermi-liquid theory mean-field responsible for the effect. In 1982 Lhuillier and Laloe found a transport equation very similar to the Leggett equation, but valid for highly-polarized dilute Boltzmann Bose and Fermi gases, and describing the ``identical spin rotation effect'' (ISRE), the analog of a Landau mean field. Coincidentally Bashkin and Meyerovich had also given equivalent descriptions of transport in polarized Boltzmann gases. That a mean-field effect could exists in dilute Boltzmann gases was theoretically surprising, but was confirmed experimentally. At low polarization the basic transverse diffusion constant D⊥ coincides with the longitudinal value D∥ however Meyerovich first pointed out that they could differ in highly polarized degenerate gases. Indeed detailed calculations (Jeon and Mullin) showed that, while D∥ is proportional to T-2, D⊥ approaches a constant (depending on polarization) at low T. Considerable controversy existed until experimental verification was achieved in 2004. The importance of ISRE again arose in 2008 as the basis of ``anomalous spin-state segregation'' in Duke and JILA experiments. More recently application of the ideas of transverse spin diffusion to strongly interacting Fermi gases has resulted in the observation of the diffusion constants at the quantum

  6. Lead diffusion in monazite

    NASA Astrophysics Data System (ADS)

    Smith, Harold A.; Giletti, Bruno J.

    1997-03-01

    We have measured the tracer diffusion rate of Pb in natural, annealed, gem-quality monazite from Alexander Co., NC, USA, and Riverside Co., CA, USA. Observations from the literature concerning low T annealing in monazite suggest the possibility that Pb diffusion at geologic conditions occurs, in effect, within a similarly annealed lattice. Our experiments were performed by evaporating an aqueous solution containing 204Pb onto a crystal face and then heating the charge to 1000-1200°C for 4 to 36 days. To the extent that the compositions of the two samples differed, we observed no effect of composition upon the rate of Pb diffusion. We do find that transport parallel to the c-axis is ˜2-5 times slower than that measured perpendicular to c. For Pb diffusion perpendicular to c, the Arrhenius parameters are Q = 180 ± 48 kJ/mol and log D0 = -14.18 ± 1.54 (for D0 in m 2/s). While these parameters now allow for a direct calculation of closure temperatures for monazite, we believe a more useful form of our data for geochronologists is the fraction of Pb lost from crystals, expressed as a function of T, time, and crystal size. We have applied this formalism to discordant monazite UPb ages from the recent literature and find that Pb diffusion at rates extrapolated from our experiments can account for the observed degree of discordancy. We suggest that, rather than employing the concept of closure temperature to evaluate possible Pb loss in monazite, the diffusion data presented here be used in Pb loss models based upon T and duration conditions appropriate for a given geological setting.

  7. Carbon Diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.; Boehnke, P.; Harrison, T. M.

    2016-12-01

    With the recent discovery of potentially biogenic carbon in 4.1 billion-year-old zircon (Bell et al., 2015), it is important to understand diffusion of C in zircon in order to assess the potential of these carbonaceous inclusions to preserve isotopic evidence of Earth's early history. In this study, we have characterized carbon diffusion in natural zircon at 1-atm and under high-pressure conditions in the presence of hydrous species. The 1-atm experiments were conducted by implanting 13C into polished, oriented slabs of zircon, with implanted samples heated in air or under buffered conditions in silica glass ampoules sealed under vacuum. High-pressure experiments (1 GPa) were conducted in a piston-cylinder apparatus, using 13C labeled glycine as the starting source (this breaks down at run conditions). In all cases, 13C distributions in zircon were measured by Nuclear Reaction Analysis (NRA) using the reaction 13C(p,γ)14N. In addition to the NRA measurements, we have also conducted analyses of carbon in zircon by ion microprobe. For diffusion parallel to c we obtain a well-constrained Arrhenius relation over the temperature range 600-1100°C. Diffusion normal to c is similar. Data from the high-pressure experiments and those run under buffered conditions also yield similar diffusivities, suggesting that carbon diffusion is not significantly affected by these parameters over the range of conditions studied. Carbon diffuses more rapidly than most cations in zircon, with the exception of lithium, but several orders of magnitude more slowly than helium. Zircon will therefore be moderately retentive of carbon. For example, diffusion distances on Gyr timescales would be on order of nm at 200°C, μm at 350°C and mm at 650°C, suggesting that carbon isotopic signatures contained within carbonaceous inclusions in zircon may be retained over long timeframes if zircons experience only moderate heating. E.A. Bell, P. Boehnke, T. M. Harrison, W.L. Mao (2015) PNAS 47, 14518-14521

  8. [Microbial diffusion and antibiotherapy].

    PubMed

    Vilain, R

    1982-01-01

    Cleaning leg ulcers depends on tissular and microbial enzymes, the production of which depends on good vascularization. When an aetiological treatment is started, the microbes ensure sufficient cleaning, leading to granulation and epidermization. Antibiotherapy is pointless. Sometimes it can be detrimental, replacing a natural growth with alien strains which cause diffusion. Very exceptionally, a short course of antibiotherapy may be necessary to cope with signs of diffusion, usually signifying a Group A streptococcal infection, with seasonal recrudescence. The Blue Pus Microbe has no special pathological significance. It merely indicates that the case has become chronic.

  9. Hydrogen diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Ingrin, Jannick; Zhang, Peipei

    2016-04-01

    Hydrogen mobility in gem quality zircon single crystals from Madagascar was investigated through H-D exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) under ambient pressure between 900 ° C to 1150 ° C. FTIR analyses were performed on oriented slices before and after each annealing run. H diffusion along [100] and [010] follow the same diffusion law D = D0exp[-E /RT], with log D0 = 2.24 ± 1.57 (in m2/s) and E = 374 ± 39 kJ/mol. H diffusion along [001] follows a slightly more rapid diffusion law, with log D0 = 1.11 ± 0.22 (in m2/s) and E = 334 ± 49 kJ/mol. H diffusion in zircon has much higher activation energy and slower diffusivity than other NAMs below 1150 ° C even iron-poor garnets which are known to be among the slowest (Blanchard and Ingrin, 2004; Kurka et al. 2005). During H-D exchange zircon incorporates also deuterium. This hydration reaction involves uranium reduction as it is shown from the exchange of U5+ and U4+ characteristic bands in the near infrared region during annealing. It is the first time that a hydration reaction U5+ + OH- = U4+ + O2- + 1/2H2, is experimentally reported. The kinetics of deuterium incorporation is slightly slower than hydrogen diffusion, suggesting that the reaction is limited by hydrogen mobility. Hydrogen isotopic memory of zircon is higher than other NAMs. Zircons will be moderately retentive of H signatures at mid-crustal metamorphic temperatures. At 500 ° C, a zircon with a radius of 300 μm would retain its H isotopic signature over more than a million years. However, a zircon is unable to retain this information for geologically significant times under high-grade metamorphism unless the grain size is large enough. Refrences Blanchard, M. and Ingrin, J. (2004) Hydrogen diffusion in Dora Maira pyrope. Physics and Chemistry of Minerals, 31, 593-605. Kurka, A., Blanchard, M. and Ingrin, J. (2005) Kinetics of hydrogen extraction and deuteration in

  10. Multispecies diffusion models: A study of uranyl species diffusion

    NASA Astrophysics Data System (ADS)

    Liu, Chongxuan; Shang, Jianying; Zachara, John M.

    2011-12-01

    Rigorous numerical description of multispecies diffusion requires coupling of species, charge, and aqueous and surface complexation reactions that collectively affect diffusive fluxes. The applicability of a fully coupled diffusion model is, however, often constrained by the availability of species self-diffusion coefficients, as well as by computational complication in imposing charge conservation. In this study, several diffusion models with variable complexity in charge and species coupling were formulated and compared to describe reactive multispecies diffusion in groundwater. Diffusion of uranyl [U(VI)] species was used as an example in demonstrating the effectiveness of the models in describing multispecies diffusion. Numerical simulations found that a diffusion model with a single, common diffusion coefficient for all species was sufficient to describe multispecies U(VI) diffusion under a steady state condition of major chemical composition, but not under transient chemical conditions. Simulations revealed that for multispecies U(VI) diffusion under transient chemical conditions, a fully coupled diffusion model could be well approximated by a component-based diffusion model when the diffusion coefficient for each chemical component was properly selected. The component-based diffusion model considers the difference in diffusion coefficients between chemical components, but not between the species within each chemical component. This treatment significantly enhanced computational efficiency at the expense of minor charge conservation. The charge balance in the component-based diffusion model can be enforced, if necessary, by adding a secondary migration term resulting from model simplification. The effect of ion activity coefficient gradients on multispecies diffusion is also discussed. The diffusion models were applied to describe U(VI) diffusive mass transfer in intragranular domains in two sediments collected from U.S. Department of Energy's Hanford 300A

  11. Investigating the molecular mechanisms through which FTY720-P causes persistent S1P1 receptor internalization

    PubMed Central

    Sykes, David A; Riddy, Darren M; Stamp, Craig; Bradley, Michelle E; McGuiness, Neil; Sattikar, Afrah; Guerini, Danilo; Rodrigues, Ines; Glaenzel, Albrecht; Dowling, Mark R; Mullershausen, Florian; Charlton, Steven J

    2014-01-01

    Background and Purpose The molecular mechanism underlying the clinical efficacy of FTY720-P is thought to involve persistent internalization and enhanced degradation of the S1P1 receptor subtype (S1P1R). We have investigated whether receptor binding kinetics and β-arrestin recruitment could play a role in the persistent internalization of the S1P1R by FTY720-P. Experimental Approach [3H]-FTY720-P and [33P]-S1P were used to label CHO-S1P1/3Rs for binding studies. Ligand efficacy was assessed through [35S]-GTPγS binding and β-arrestin recruitment. Metabolic stability was evaluated using a bioassay measuring intracellular Ca2+ release. CHO-S1P1/3R numbers were determined, following FTY720-P treatment using flow cytometry. Key Results The kinetic off-rate of [3H]-FTY720-P from the S1P1R was sixfold slower than from the S1P3R, and comparable to [33P]-S1P dissociation from S1P1/3Rs. S1P and FTY720-P stimulated [35S]-GTPγS incorporation to similar degrees, but FTY720-P was over 30-fold less potent at S1P3Rs. FTY720-P stimulated a higher level of β-arrestin recruitment at S1P1Rs, 132% of the total recruited by S1P. In contrast, FTY720-P was a weak partial agonist at S1P3R, stimulating just 29% of the total β-arrestin recruited by S1P. Internalization experiments confirmed that cell surface expression of the S1P1R but not the S1P3R was reduced following a pulse exposure to FTY720-P, which is metabolically stable unlike S1P. Conclusions and Implications FTY720-P and S1P activation of the S1P1R results in receptor internalization as a consequence of an efficient recruitment of β-arrestin. The combination of slow off-rate, efficacious β-arrestin recruitment and metabolic stability all contribute to FTY720-P's ability to promote prolonged S1P1R internalization and may be critical factors in its efficacy in the clinic. PMID:24641481

  12. Modulation of HIV-1 Gag NC/p1 cleavage efficiency affects protease inhibitor resistance and viral replicative capacity.

    PubMed

    van Maarseveen, Noortje M; Andersson, Dan; Lepšík, Martin; Fun, Axel; Schipper, Pauline J; de Jong, Dorien; Boucher, Charles A B; Nijhuis, Monique

    2012-04-01

    Mutations in the substrate of HIV-1 protease, especially changes in the NC/p1 cleavage site, can directly contribute to protease inhibitor (PI) resistance and also compensate for defects in viral replicative capacity (RC) due to a drug resistant protease. These NC/p1 changes are known to enhance processing of the Gag protein. To investigate the capacity of HIV-1 to modulate Gag cleavage and its consequences for PI resistance and RC, we performed a detailed enzymatic and virological analysis using a set of PI resistant NC/p1 variants (HXB2431V, HXB2436E+437T, HXB2437T and HXB2437V). Here, we demonstrate that single NC/p1 mutants, which displayed only a slight increase in PI resistance did not show an obvious change in RC. In contrast, the double NC/p1 mutant, which displayed a clear increase in processing efficiency and PI resistance, demonstrated a clear reduction in RC. Cleavage analysis showed that a tridecameric NC/p1 peptide representing the double NC/p1 mutant was cleaved in two specific ways instead of one.The observed decrease in RC for the double NC/p1 mutant (HXB2436E+437T) could (partially) be restored by either reversion of the 436E change or by acquisition of additional changes in the NC/p1 cleavage site at codon 435 or 438 as was revealed during in vitro evolution experiments. These changes not only restored RC but also reduced PI resistance levels. Furthermore these changes normalized Gag processing efficiency and obstructed the novel secondary cleavage site observed for the double NC/p1 mutant. The results of this study clearly demonstrate that HIV-1 can modulate Gag processing and thereby PI resistance. Distinct increases in Gag cleavage and PI resistance result in a reduced RC that can only be restored by amino acid changes in NC/p1 which reduce Gag processing to an optimal rate.

  13. Detection and Whole-Genome Characterization of a G8P[1] Group A Rotavirus Strain from Deer

    PubMed Central

    Peterson, Jessica

    2016-01-01

    Rotavirus A strain 14-02218-2, with genome constellation G8P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H3, was isolated from newborn fawns. The 14-02218-2 rotavirus strain is related to bovine and bovine-like rotavirus strains. To our knowledge, this is the first report on whole-genome-based characterization of a deer rotavirus G8P[1] strain. PMID:27932644

  14. Assembly of Saccharomyces cerevisiae ribosomal stalk: binding of P1 proteins is required for the interaction of P2 proteins.

    PubMed

    Zurdo, J; Parada, P; van den Berg, A; Nusspaumer, G; Jimenez-Diaz, A; Remacha, M; Ballesta, J P

    2000-08-01

    The yeast ribosomal stalk is formed by a protein pentamer made of the 38 kDa P0 and four 12 kDa acidic P1/P2. The interaction of recombinant acidic proteins P1 alpha and P2 beta with ribosomes from Saccharomyces cerevisiae D4567, lacking all the 12 kDa stalk components, has been used to study the in vitro assembly of this important ribosomal structure. Stimulation of the ribosome activity was obtained by incubating simultaneously the particles with both proteins, which were nonphosphorylated initially and remained unmodified afterward. The N-terminus state, free or blocked, did not affect either the binding or reactivating activity of both proteins. Independent incubation with each protein did not affect the activity of the particles, however, protein P2 beta alone was unable to bind the ribosome whereas P1 alpha could. The binding of P1 alpha alone is a saturable process in acidic-protein-deficient ribosomes and does not take place in complete wild-type particles. Binding of P1 proteins in the absence of P2 proteins takes also place in vivo, when protein P1 beta is overexpressed in S. cerevisiae. In contrast, protein P2 beta is not detected in the ribosome in the P1-deficient D67 strain despite being accumulated in the cytoplasm. The results confirm that neither phosphorylation nor N-terminal blocking of the 12 kDa acidic proteins is required for the assembly and function of the yeast stalk. More importantly, and regardless of the involvement of other elements, they indicate that stalk assembling is a coordinated process, in which P1 proteins would provide a ribosomal anchorage to P2 proteins, and P2 components would confer functionality to the complex.

  15. Direct regulatory immune activity of lactic acid bacteria on Der p 1-pulsed dendritic cells from allergic patients.

    PubMed

    Pochard, Pierre; Hammad, Hamida; Ratajczak, Céline; Charbonnier-Hatzfeld, Anne-Sophie; Just, Nicolas; Tonnel, André-Bernard; Pestel, Joël

    2005-07-01

    Lactic acid bacteria (LAB) are suggested to play a regulatory role in the development of allergic reactions. However, their potential effects on dendritic cells (DCs) directing the immune polarization remain unclear. The immunologic effect of Lactobacillus plantarum NCIMB 8826 (LAB1) on monocyte-derived dendritic cells (MD-DCs) from patients allergic to house dust mite was evaluated. MD-DCs were stimulated for 24 hours with the related allergen Der p 1 in the presence or absence of LAB1. Cell-surface markers were assessed by means of FACS analysis, and the key polarizing cytokines IL-12 and IL-10 were quantified. The subsequent regulatory effect of pulsed MD-DCs on naive or memory T cells was evaluated by determining the T-cell cytokine profile. LAB1 induced the maturation of MD-DCs, even if pulsed with Der p 1. Interestingly, after incubation with LAB1 and Der p 1, MD-DCs produced higher amounts of IL-12 than Der p 1-pulsed DCs. Indeed, the T H 2 cytokine (IL-4 and IL-5) production observed when naive or memory autologous T cells were cocultured with Der p 1-pulsed MD-DCs was highly reduced in the presence of LAB1. Finally, in contrast to naive or memory T cells exposed once to Der p 1-pulsed DCs, T cells stimulated by MD-DCs pulsed with Der p 1 and LAB1 failed to produce T H 2 cytokines in response to a new stimulation with Der p 1-pulsed DCs. Thus in the presence of LAB1, MD-DCs from allergic patients tend to reorientate the T-cell response toward a beneficial T H 1 profile.

  16. Enhancement of nuclease P1 production by Penicillium citrinum YL104 immobilized on activated carbon filter sponge.

    PubMed

    Zhao, Nan; Ren, Hengfei; Li, Zhenjian; Zhao, Ting; Shi, Xinchi; Cheng, Hao; Zhuang, Wei; Chen, Yong; Ying, Hanjie

    2015-02-01

    The efficiency of current methods for industrial production of the enzyme nuclease P1 is limited. In this study, we sought to improve fermentation methods for the production of nuclease P1. An immobilized fermentation system using an activated carbon filter sponge as a carrier was used for the production of nuclease P1. In an airlift internal loop reactor (ALR), the fermentation performance of three different fermentation modes, including free-cell fermentation, repeated-batch fermentation, and semi-continuous immobilized fermentation, were compared. The fermentation kinetics in the fermentation broth of the three fermentation modes, including dissolved oxygen (DO), pH value, cell concentration, residual sugar concentration, and enzyme activity, were tested. The productivity of semi-continuous immobilized fermentation reached 8.76 U/mL/h, which was 33.3 and 80.2% higher than that of repeated-batch fermentation and free-cell fermentation, respectively. The sugar consumption of free-cell, repeated-batch, and semi-continuous immobilized fermentations was 41.2, 30.8, and 25.9 g/L, respectively. These results showed that immobilized-cell fermentation by using Penicillium citrinum with activated carbon filter sponge in an ALR was advantageous for nuclease P1 production, especially in the semi-continuous immobilized fermentation mode. In spite of the significant improvement in nuclease P1 production in semi-continuous immobilized fermentation mode, the specific activity of nuclease P1 was almost equal among the three fermentation modes.

  17. Alfalfa mosaic virus replicase proteins, P1 and P2, localize to the tonoplast in the presence of virus RNA

    SciTech Connect

    Ibrahim, Amr; Hutchens, Heather M.; Howard Berg, R.; Sue Loesch-Fries, L.

    2012-11-25

    To identify the virus components important for assembly of the Alfalfa mosaic virus replicase complex, we used live cell imaging of Arabidopsis thaliana protoplasts that expressed various virus cDNAs encoding native and GFP-fusion proteins of P1 and P2 replicase proteins and full-length virus RNAs. Expression of P1-GFP alone resulted in fluorescent vesicle-like bodies in the cytoplasm that colocalized with FM4-64, an endocytic marker, and RFP-AtVSR2, RabF2a/Rha1-mCherry, and RabF2b/Ara7-mCherry, all of which localize to multivesicular bodies (MVBs), which are also called prevacuolar compartments, that mediate traffic to the lytic vacuole. GFP-P2 was driven from the cytosol to MVBs when expressed with P1 indicating that P1 recruited GFP-P2. P1-GFP localized on the tonoplast, which surrounds the vacuole, in the presence of infectious virus RNA, replication competent RNA2, or P2 and replication competent RNA1 or RNA3. This suggests that a functional replication complex containing P1, P2, and a full-length AMV RNA assembles on MVBs to traffic to the tonoplast.

  18. Healing activity of proteolytic fraction (P1G10) from Vasconcellea cundinamarcensis in a cutaneous wound excision model.

    PubMed

    Freitas, K M; Barcelos, L S; Caliari, M V; Salas, C E; Lopes, M T P

    2017-10-05

    The proteolytic enzymes from Vasconcellea cundinamarcensis have demonstrated efficacy to accelerate healing of skin lesions. We report here the efficacy of the proteolytic fraction - P1G10 during repair of excisional wounds in rodent model and analyze possible mediators involved. Using 0.05% P1G10 we observed on day 3rd increased wound contraction accompanied by an increase in activated neutrophils and VEGF relative to the control. On day 7th neutrophils returned to normal levels, and at 0.01% P1G10, an increase in NAG activity used to monitor monocyte/macrophage, was observed. On the other hand, on day 7th, we observed a decrease in TGF-β at 0.05% P1G10, accompanied by an increased transformation of the latent TGF-β to its active form. Also, on day 7th a reduction in MMP-9 activity and the number of apoptotic cells was observed along with an increase in fibroblast levels. Morphometrically, it appears that treatment with P1G10 accelerates the decline of initial inflammatory phase and reduces some unwanted effects likely caused by remaining TGF-β or MMPs, thus enhancing the quality of scar. Overall, these data suggest that the active proteolytic fraction P1G10 enhances the efficacy of repair in excisional cutaneous wounds. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Changes in predictive cuing modulate the hemispheric distribution of the P1 inhibitory response to attentional targets.

    PubMed

    Lasaponara, Stefano; D' Onofrio, Marianna; Dragone, Alessio; Pinto, Mario; Caratelli, Ludovica; Doricchi, Fabrizio

    2017-03-07

    Brain activity related to orienting of attention with spatial cues and brain responses to attentional targets are influenced the probabilistic contingency between cues and targets. Compared to predictive cues, cues predicting at chance the location of targets reduce the filtering out of uncued locations and the costs in reorienting attention to targets presented at these locations. Slagter et al. (2016) have recently suggested that the larger target related P1 component that is found in the hemisphere ipsilateral to validly cued targets reflects stimulus-driven inhibition in the processing of the unstimulated side of space contralateral to the same hemisphere. Here we verified whether the strength of this inhibition and the amplitude of the corresponding P1 wave are modulated by the probabilistic link between cues and targets. Healthy participants performed a task of endogenous orienting once with predictive and once with non-predictive directional cues. In the non-predictive condition we observed a drop in the amplitude of the P1 ipsilateral to the target and in the costs of reorienting. No change in the inter-hemispheric latencies of the P1 was found between the two predictive conditions. The N1 facilitatory component was unaffected by predictive cuing. These results show that the predictive context modulates the strength of the inhibitory P1 response and that this modulation is not matched with changes in the inter-hemispheric interaction between the P1 generators of the two hemispheres.

  20. Polarimetry, photometry, and spectroscopy of comet C/2009 P1 (Garradd)

    NASA Astrophysics Data System (ADS)

    Ivanova, Oleksandra; Rosenbush, Vera; Afanasiev, Viktor; Kiselev, Nikolai

    2017-03-01

    We present the results of photometry, linear spectropolarimetry, and imaging circular polarimetry of comet C/2009 P1 (Garradd) performed at the 6-m telescope BTA of the Special Astrophysical Observatory (Russia) equipped by the multi-mode focal reducer SCORPIO-2. The comet was observed at two epochs post-perihelion: on February 2-14, 2012 at rh˜1.6 au and α˜36°; and on April 14-21, 2012 at rh˜2.2 au and α˜27°. The spatial maps of the relative intensity and circular polarization as well as the spectral distribution of linear polarization are presented. There were two features (dust and gas tails) oriented in the solar and antisolar directions on February 2 and 14 that allowed us to determine rotation period of the nucleus as 11.1 ± 0.8 hours. We detected emissions of C2, C3, CN, CH, NH2 molecules as well as CO+ and H2O+ ions, along with a high level of the dust continuum. On February 2, the degree of linear polarization in the continuum, within the wavelength range of 0.67-0.68 μm, was about 5 ± 0.2% in the near-nucleus region up to ˜6000 km and decreased to about 3 ± 0.2% at ˜40,000 km. After correction for the continuum contamination, the inherent degree of polarization in the emission band C2(Δν= 0) is about 3.3%. We detected a small increase of linear polarization with the wavelength with the spectral gradient ΔP/Δλ = +4 ± 0.8%/μm and ΔP/Δλ = + 6.2 ± 1.3%/μm, respectively, on February 2 and April 14. Linear polarization indicates that this dust-rich comet can be attributed to the high-Pmax comets. The left-handed (negative) circular polarization at the level approximately from ˜0.06 ± 0.02% to ˜0.4 ± 0.02% was observed at the distances up to 3×104 km from the nucleus on February 14 and April 21, respectively.

  1. Distant Jupiter family Comet P/2011 P1 (McNaught)

    NASA Astrophysics Data System (ADS)

    Korsun, Pavlo P.; Ivanova, Oleksandra V.; Afanasiev, Viktor L.; Kulyk, Irina V.

    2016-03-01

    The spectra and images obtained through broadband BVRc filters for Jupiter family Comet P/2011 P1 (McNaught) were analyzed. We observed the comet on November 24, 2011, when its heliocentric distance was 5.43 AU. Two dimensional long slit spectra and photometric images were obtained using the focal reducer SCORPIO attached to the prime focus of the 6-m telescope BTA (SAO RAS, Russia). The spectra cover the wavelength range of 4200-7000 Å. No emissions of C2 and CO+, which are expected in this wavelength region, were detected above 3σ level. An upper limit in gas production rate of C2 is expected to be 1.1 × 1024 mol s-1. The continuum shows a reddening effect with the normalized gradient of reflectivity along dispersion of 5.1 ± 1.2% per 1000 Å. The color indices (B-V) = 0.89 ± 0.09 and (V-Rc) = 0.42 ± 0.07 for the nucleus region or (B-V) = 0.68 ± 0.12 and (V-Rc) = 0.39 ± 0.10 for the coma region, which are derived from the photometric data, also evidence that the color of the cometary nucleus and dust are redder with respect to the Sun. The normalized gradients of 5.9 ± 2.9% per 1000 Å and 2.6 ± 1.9% per 1000 Å for VRc filters were obtained for the cometary nucleus and the dust coma, respectively. The estimated dust mass production rate is about 12 kg s-1 for Rc filter. The dust coma like a spiral galaxy edge-on was fitted using a Monte Carlo model. Since it is expected that the particles forming the dust coma consist of ;dirty; ice, Greenberg's model was adopted to track grains with an icy component that evaporates slowly when exposed to solar radiation. The observed coma was fitted assuming two isolated active zones located at the cometocentric latitudes of -8° and -35° with outflow of the dust within the cones having half opening angles of 8° and 70°, respectively. About, 45% and 55% of the observed dust were originated from the high collimated and low collimated active zones, respectively. The spin-axis of the rotating nucleus is positioned in

  2. The IL4-VNTR P1 Allele, IL4-VNTR P2P2 Genotype, and IL4-VNTR_IL6-174CG P2P1-GG Genotype Are Associated with an Increased Risk of Brucellosis.

    PubMed

    Gunal, Ozgur; Yigit, Serbulent; Yalcın, Arzu Didem; Celik, Betul; Barut, Sener; Demir, Osman; Ates, Omer; Duygu, Fazilet; Kaya, Safak; Rustemoglu, Aydin; Sezer, Ozlem

    2017-01-24

    In this study, associations between IL-4, IL-6, and macrophage migration inhibitory factor (MIF) polymorphisms and susceptibility to brucellosis were investigated. Consecutive adult patients with no known treatment against brucellosis and who did not have any other autoimmune and/or chronic disorders, were included in this study (n = 120, Group I). Age and sex-matched controls who had no other autoimmune and/or chronic disorders were also included (n = 120, healthy volunteers, Group II). The IL4_P2P2 genotype, IL4_P1 allele, and IL4_variable number of tandem repeats (VNTR)_IL6-174CG compound genotype were found to be more frequent in the patient group than in control subjects. There were significant differences between the patients and controls with respect to the frequencies of the IL4_P2P2 genotype (77.5% versus 87.5%; p = 0.001; OR, 0.36; 95% confidence interval [CI], 0.21-0.62) and the IL4_P1 allele (12.1% versus 6.7%; p = 0.030; OR, 0.92; CI, 1.02-3.64). The IL4-VNTR_IL6-174CG compound genotype was also present at a significantly higher frequency in the patient group than in control subjects (11.7% versus 4.2%; p = 0.027, OR, 3.04; CI, 1.06-8.68). No statistically significant differences in the frequencies of the IL-6-174, MIF-173, IL-4_P1P1, and IL4_P2P1 genotypes were observed between patients and control subjects. The IL4_VNTR P1 allele, P2P2 genotypes, and IL4-VNTR_IL6-174CG P2P1-GG genotypes are common in southern Turkey, and carriers of these polymorphisms are susceptible to brucellosis.

  3. DEVELOPMENT, DIFFUSION, AND EVALUATION.

    ERIC Educational Resources Information Center

    GUBA, EGON G.

    THE KNOWLEDGE GAP BETWEEN INITIAL RESEARCH AND FINAL USE IS DISCUSSED IN TERMS OF THE FOUR STATES OF THE THEORY-PRACTICE CONTINUUM (RESEARCH, DEVELOPMENT, DIFFUSION, AND ADOPTION). THE TWO MIDDLE STAGES ARE EMPHASIZED. RESEARCH AND DEVELOPMENT CENTERS, REGIONAL EDUCATIONAL LABORATORIES, AND TITLE III PROJECTS ARE SUGGESTED AS AGENCIES RESPONSIBLE…

  4. Diffusion in random networks

    DOE PAGES

    Zhang, Duan Z.; Padrino, Juan C.

    2017-06-01

    The ensemble averaging technique is applied to model mass transport by diffusion in random networks. The system consists of an ensemble of random networks, where each network is made of pockets connected by tortuous channels. Inside a channel, fluid transport is assumed to be governed by the one-dimensional diffusion equation. Mass balance leads to an integro-differential equation for the pocket mass density. The so-called dual-porosity model is found to be equivalent to the leading order approximation of the integration kernel when the diffusion time scale inside the channels is small compared to the macroscopic time scale. As a test problem,more » we consider the one-dimensional mass diffusion in a semi-infinite domain. Because of the required time to establish the linear concentration profile inside a channel, for early times the similarity variable is xt$-$1/4 rather than xt$-$1/2 as in the traditional theory. We found this early time similarity can be explained by random walk theory through the network.« less

  5. Lung diffusion testing

    MedlinePlus

    ... the blood from the lungs, and to allow carbon dioxide to "diffuse" from the blood into the lungs. How the Test is Performed You breathe in (inhale) air containing a very small amount of carbon monoxide and a tracer gas, such as methane ...

  6. Water vapor diffusion membranes

    NASA Technical Reports Server (NTRS)

    Holland, F. F., Jr.; Smith, J. K.

    1974-01-01

    The program is reported, which was designed to define the membrane technology of the vapor diffusion water recovery process and to test this technology using commercially available or experimental membranes. One membrane was selected, on the basis of the defined technology, and was subjected to a 30-day demonstration trial.

  7. Osmosis and Diffusion

    ERIC Educational Resources Information Center

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  8. Osmosis and Diffusion

    ERIC Educational Resources Information Center

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  9. Nanocrystal diffusion doping.

    PubMed

    Vlaskin, Vladimir A; Barrows, Charles J; Erickson, Christian S; Gamelin, Daniel R

    2013-09-25

    A diffusion-based synthesis of doped colloidal semiconductor nanocrystals is demonstrated. This approach involves thermodynamically controlled addition of both impurity cations and host anions to preformed seed nanocrystals under equilibrium conditions, rather than kinetically controlled doping during growth. This chemistry allows thermodynamic crystal compositions to be prepared without sacrificing other kinetically trapped properties such as shape, size, or crystallographic phase. This doping chemistry thus shares some similarities with cation-exchange reactions, but proceeds without the loss of host cations and excels at the introduction of relatively unreactive impurity ions that have not been previously accessible using cation exchange. Specifically, we demonstrate the preparation of Cd(1-x)Mn(x)Se (0 ≤ x ≤ ∼0.2) nanocrystals with narrow size distribution, unprecedentedly high Mn(2+) content, and very large magneto-optical effects by diffusion of Mn(2+) into seed CdSe nanocrystals grown by hot injection. Controlling the solution and lattice chemical potentials of Cd(2+) and Mn(2+) allows Mn(2+) diffusion into the internal volumes of the CdSe nanocrystals with negligible Ostwald ripening, while retaining the crystallographic phase (wurtzite or zinc blende), shape anisotropy, and ensemble size uniformity of the seed nanocrystals. Experimental results for diffusion doping of other nanocrystals with other cations are also presented that indicate this method may be generalized, providing access to a variety of new doped semiconductor nanostructures not previously attainable by kinetic routes or cation exchange.

  10. Diffusion on Cu surfaces

    NASA Technical Reports Server (NTRS)

    Karimi, Majid

    1993-01-01

    Understanding surface diffusion is essential in understanding surface phenomena, such as crystal growth, thin film growth, corrosion, physisorption, and chemisorption. Because of its importance, various experimental and theoretical efforts have been directed to understand this phenomena. The Field Ion Microscope (FIM) has been the major experimental tool for studying surface diffusion. FIM have been employed by various research groups to study surface diffusion of adatoms. Because of limitations of the FIM, such studies are only limited to a few surfaces: nickel, platinum, aluminum, iridium, tungsten, and rhodium. From the theoretical standpoint, various atomistic simulations are performed to study surface diffusion. In most of these calculations the Embedded Atom Method (EAM) along with the molecular static (MS) simulation are utilized. The EAM is a semi-empirical approach for modeling the interatomic interactions. The MS simulation is a technique for minimizing the total energy of a system of particles with respect to the positions of its particles. One of the objectives of this work is to develop the EAM functions for Cu and use them in conjunction with the molecular static (MS) simulation to study diffusion of a Cu atom on a perfect as well as stepped Cu(100) surfaces. This will provide a test of the validity of the EAM functions on Cu(100) surface and near the stepped environments. In particular, we construct a terrace-ledge-kink (TLK) model and calculate the migration energies of an atom on a terrace, near a ledge site, near a kink site, and going over a descending step. We have also calculated formation energies of an atom on the bare surface, a vacancy in the surface, a stepped surface, and a stepped-kink surface. Our results are compared with the available experimental and theoretical results.

  11. Erbium diffusion in silicon dioxide

    SciTech Connect

    Lu Yingwei; Julsgaard, B.; Petersen, M. Christian; Jensen, R. V. Skougaard; Pedersen, T. Garm; Pedersen, K.; Larsen, A. Nylandsted

    2010-10-04

    Erbium diffusion in silicon dioxide layers prepared by magnetron sputtering, chemical vapor deposition, and thermal growth has been investigated by secondary ion mass spectrometry, and diffusion coefficients have been extracted from simulations based on Fick's second law of diffusion. Erbium diffusion in magnetron sputtered silicon dioxide from buried erbium distributions has in particular been studied, and in this case a simple Arrhenius law can describe the diffusivity with an activation energy of 5.3{+-}0.1 eV. Within a factor of two, the erbium diffusion coefficients at a given temperature are identical for all investigated matrices.

  12. Instrumentation in Diffuse Optical Imaging

    PubMed Central

    Zhang, Xiaofeng

    2014-01-01

    Diffuse optical imaging is highly versatile and has a very broad range of applications in biology and medicine. It covers diffuse optical tomography, fluorescence diffuse optical tomography, bioluminescence, and a number of other new imaging methods. These methods of diffuse optical imaging have diversified instrument configurations but share the same core physical principle – light propagation in highly diffusive media, i.e., the biological tissue. In this review, the author summarizes the latest development in instrumentation and methodology available to diffuse optical imaging in terms of system architecture, light source, photo-detection, spectral separation, signal modulation, and lastly imaging contrast. PMID:24860804

  13. P1 Epigenetic Regulation in Leaves of High Altitude Maize Landraces: Effect of UV-B Radiation

    PubMed Central

    Rius, Sebastián P.; Emiliani, Julia; Casati, Paula

    2016-01-01

    P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces. Our results demonstrate that DNA methylation in the P1 proximal promoter, intron1 and intron2 is decreased by UV-B in all lines analyzed; however, the basal DNA methylation levels are lower in the landraces than in B73, a low altitude inbred line. DNA demethylation by UV-B is accompanied by a decrease in H3 methylation at Lys 9 and 27, and by an increase in H3 acetylation. smRNAs complementary to specific regions of the proximal promoter and of intron 2 3′ end are also decreased by UV-B; interestingly, P1 smRNA levels are lower in the landraces than in B73 both under control conditions and after UV-B exposure, suggesting that smRNAs regulate P1 expression by UV-B in maize leaves. Finally, we investigated if different P1 targets in flower tissues are also regulated by this transcription factor in response to UV-B. Some targets analyzed show an induction in maize landraces in response to UV-B, with higher basal expression levels in the landraces than in B73; however, not all the transcripts analyzed were found to be regulated by UV-B in leaves. PMID:27148340

  14. P1 Epigenetic Regulation in Leaves of High Altitude Maize Landraces: Effect of UV-B Radiation.

    PubMed

    Rius, Sebastián P; Emiliani, Julia; Casati, Paula

    2016-01-01

    P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces. Our results demonstrate that DNA methylation in the P1 proximal promoter, intron1 and intron2 is decreased by UV-B in all lines analyzed; however, the basal DNA methylation levels are lower in the landraces than in B73, a low altitude inbred line. DNA demethylation by UV-B is accompanied by a decrease in H3 methylation at Lys 9 and 27, and by an increase in H3 acetylation. smRNAs complementary to specific regions of the proximal promoter and of intron 2 3' end are also decreased by UV-B; interestingly, P1 smRNA levels are lower in the landraces than in B73 both under control conditions and after UV-B exposure, suggesting that smRNAs regulate P1 expression by UV-B in maize leaves. Finally, we investigated if different P1 targets in flower tissues are also regulated by this transcription factor in response to UV-B. Some targets analyzed show an induction in maize landraces in response to UV-B, with higher basal expression levels in the landraces than in B73; however, not all the transcripts analyzed were found to be regulated by UV-B in leaves.

  15. Structural characterization of yeast acidic ribosomal P proteins forming the P1A-P2B heterocomplex.

    PubMed

    Tchórzewski, Marek; Krokowski, Dawid; Boguszewska, Aleksandra; Liljas, Anders; Grankowski, Nikodem

    2003-04-01

    Acidic ribosomal P proteins form a distinct lateral protuberance on the 60S ribosomal subunit. In yeast, this structure is composed of two heterocomplexes (P1A-P2B and P1B-P2A) attached to the ribosome with the aid of the P0 protein. In solution, the isolated P proteins P1A and P2B have a flexible structure with some characteristics of a molten globule [Zurdo, J., et al. (2000) Biochemistry 39, 8935-8943]. In this report, the structure of P1A-P2B heterocomplex from Saccharomyces cerevisiae is investigated by means of size-exclusion chromatography, chemical cross-linking, circular dichroism, light scattering, and fluorescence spectroscopy. The circular dichroism experiment shows that the complex could be ranked in the tertiary class of all-alpha proteins, with an average alpha-helical content of approximately 65%. Heat and urea denaturation experiments reveal that the P1A-P2B complex, unlike the isolated proteins, has a full cooperative transition which can be fitted into a two-state folding-unfolding model. The behavior of the complex in the presence of 2,2,2-trifluoroethanol also resembles a two-state folding-unfolding transition, further supporting the idea that the heterocomplex contains well-packed side chains. In conclusion, the P1A-P2B heterocomplex, unlike the isolated proteins, has a well-defined hydrophobic core. Consequently, the complex can put up its structure without additional ribosomal components, so the heterodimeric complex reflects the intrinsic properties of the two analyzed proteins, indicating thus that this is the only possible configuration of the P1A and P2B proteins on the ribosomal stalk structure.

  16. Identification of a supramolecular functional architecture of Streptococcus mutans adhesin P1 on the bacterial cell surface.

    PubMed

    Heim, Kyle P; Sullan, Ruby May A; Crowley, Paula J; El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Tang, Wenxing; Besingi, Richard; Dufrene, Yves F; Brady, L Jeannine

    2015-04-03

    P1 (antigen I/II) is a sucrose-independent adhesin of Streptococcus mutans whose functional architecture on the cell surface is not fully understood. S. mutans cells subjected to mechanical extraction were significantly diminished in adherence to immobilized salivary agglutinin but remained immunoreactive and were readily aggregated by fluid-phase salivary agglutinin. Bacterial adherence was restored by incubation of postextracted cells with P1 fragments that contain each of the two known adhesive domains. In contrast to untreated cells, glutaraldehyde-treated bacteria gained reactivity with anti-C-terminal monoclonal antibodies (mAbs), whereas epitopes recognized by mAbs against other portions of the molecule were masked. Surface plasmon resonance experiments demonstrated the ability of apical and C-terminal fragments of P1 to interact. Binding of several different anti-P1 mAbs to unfixed cells triggered release of a C-terminal fragment from the bacterial surface, suggesting a novel mechanism of action of certain adherence-inhibiting antibodies. We also used atomic force microscopy-based single molecule force spectroscopy with tips bearing various mAbs to elucidate the spatial organization and orientation of P1 on living bacteria. The similar rupture lengths detected using mAbs against the head and C-terminal regions, which are widely separated in the tertiary structure, suggest a higher order architecture in which these domains are in close proximity on the cell surface. Taken together, our results suggest a supramolecular organization in which additional P1 polypeptides, including the C-terminal segment originally identified as antigen II, associate with covalently attached P1 to form the functional adhesive layer.

  17. A randomized control comparison study of culture media (HTF versus P1) for human in vitro fertilization.

    PubMed

    Artini, Paolo G; Valentino, Valeria; Cela, Vito; Cristello, Francesca; Vitè, Alessandra; Genazzani, Andrea R

    2004-10-15

    It is now widely accepted that increasing the number of replacement embryos (>3 embryos per embryo transfer [ET]) is associated with an increased risk of multiple pregnancies. While embryo reduction is often proposed when there is a high risk of multiple pregnancies, it is a difficult decision for the couple. For this reason, different studies have focused on single embryo transfer, more precisely blastocyst transfer. The aim of the study is to confirm that phosphate-free culture media can be used to generate greater quality embryos. We carried out a study to compare the efficacy of human tubal fluid (HTF) versus preimplantation stage one (P1) as culture media for assisted reproductive therapy (ART). In 109 nonselected patients, we obtained an embryo fertilization rate with HTF and P1 culture media of 58.6 and 62.5% (P = 0.003), respectively. After 48 and 72 h, the morphology was similar for both P1 and HTF embryos in most patients. However, in the same patients, when HTF embryo quality was low (15.4%), P1 embryo quality was significantly higher 68.7% (P = 0.002). Some embryos were transferred at 48 h and some at 72 h after retrieval, in a randomized manner. We transferred a maximum of up to three embryos per ET. The implantation rate was significantly different; at 48 h, it was 6.8 and 12.2% for HTF and P1, respectively (P = 0.02). The pregnancy rate was 17.1% for HTF embryos and 23.7% for P1 embryos (P = 0.02). Therefore, we observed a significant difference between P1 and HTF in the fertilization rate, in embryo quality, in implantation rate and in pregnancy rate. But the most important difference between this study and others is that every patient was the control of herself, so we eliminated every variable.

  18. Differential regulation of the parathyroid hormone-related protein gene P1 and P3 promoters by cAMP.

    PubMed

    Chilco, P J; Leopold, V; Zajac, J D

    1998-03-16

    The role of calcitonin, and other agonists which activate the cAMP pathway, in regulating transcription of the human parathyroid hormone-related protein (PTHrP) gene was investigated in a human lung cancer cell line (BEN). Both calcitonin and forskolin caused a 5-6-fold increase in transcription initiated from both the P1 and P3 promoters, but with no observed effect on the P2 promoter. Maximal 6-fold activation of the P1 promoter occurred at 16 h post-stimulation and effects of calcitonin were observed within the pM range. The PKC agonist, phorbol 12-myristate 13-acetate diester (PMA), did not modulate transcription initiated from the P1 promoter. The ionophore ionomycin had a small effect on transcription of the P1 promoter, and transcriptional control may involve an interaction between the cAMP and intracellular calcium second messenger pathways. Deletion mapping studies indicated that increases in transcription of the human PTHrP gene is being mediated via a CRE element situated at -3313 to -3306 upstream of the P1 promoter. Mutational analysis of this CRE element confirmed a role for this sequence in mediating the increase in transcription effected by cAMP. Consistent with these transfection studies, RT-PCR of PTHrP mRNA also indicated a significant increase in transcripts generated from the P1 promoter. Gel retardation assays utilising a fragment of the P1 promoter region, encompassing the putative CRE, determined that nuclear proteins were binding to this region. Competition binding studies with labelled probe and cold competitors determined that the binding was specific for this sequence. A wild-type CRE consensus oligonucleotide also competed for binding with this sequence.

  19. mRNA Capping by Venezuelan Equine Encephalitis Virus nsP1: Functional Characterization and Implications for Antiviral Research.

    PubMed

    Li, Changqing; Guillén, Jaime; Rabah, Nadia; Blanjoie, Alexandre; Debart, Françoise; Vasseur, Jean-Jacques; Canard, Bruno; Decroly, Etienne; Coutard, Bruno

    2015-08-01

    Alphaviruses are known to possess a unique viral mRNA capping mechanism involving the viral nonstructural protein nsP1. This enzyme harbors methyltransferase (MTase) and nsP1 guanylylation (GT) activities catalyzing the transfer of the methyl group from S-adenosylmethionine (AdoMet) to the N7 position of a GTP molecule followed by the formation of an m(7)GMP-nsP1 adduct. Subsequent transfer of m(7)GMP onto the 5' end of the viral mRNA has not been demonstrated in vitro yet. Here we report the biochemical characterization of Venezuelan equine encephalitis virus (VEEV) nsP1. We have developed enzymatic assays uncoupling the different reactions steps catalyzed by nsP1. The MTase and GT reaction activities were followed using a nonhydrolyzable GTP (GIDP) substrate and an original Western blot assay using anti-m3G/m(7)G-cap monoclonal antibody, respectively. The GT reaction is stimulated by S-adenosyl-l-homocysteine (Ado-Hcy), the product of the preceding MTase reaction, and metallic ions. The covalent linking between nsP1 and m(7)GMP involves a phosphamide bond between the nucleotide and a histidine residue. Final guanylyltransfer onto RNA was observed for the first time with an alphavirus nsP1 using a 5'-diphosphate RNA oligonucleotide whose sequence corresponds to the 5' end of the viral genome. Alanine scanning mutagenesis of residues H37, H45, D63, E118, Y285, D354, R365, N369, and N375 revealed their respective roles in MT and GT reactions. Finally, the inhibitory effects of sinefungin, aurintricarboxylic acid (ATA), and ribavirin triphosphate on MTase and capping reactions were investigated, providing possible avenues for antiviral research. Emergence or reemergence of alphaviruses represents a serious health concern, and the elucidation of their replication mechanisms is a prerequisite for the development of specific inhibitors targeting viral enzymes. In particular, alphaviruses are able, through an original reaction sequence, to add to their mRNA a cap

  20. mRNA Capping by Venezuelan Equine Encephalitis Virus nsP1: Functional Characterization and Implications for Antiviral Research

    PubMed Central

    Li, Changqing; Guillén, Jaime; Rabah, Nadia; Blanjoie, Alexandre; Debart, Françoise; Vasseur, Jean-Jacques; Canard, Bruno; Decroly, Etienne

    2015-01-01

    ABSTRACT Alphaviruses are known to possess a unique viral mRNA capping mechanism involving the viral nonstructural protein nsP1. This enzyme harbors methyltransferase (MTase) and nsP1 guanylylation (GT) activities catalyzing the transfer of the methyl group from S-adenosylmethionine (AdoMet) to the N7 position of a GTP molecule followed by the formation of an m7GMP-nsP1 adduct. Subsequent transfer of m7GMP onto the 5′ end of the viral mRNA has not been demonstrated in vitro yet. Here we report the biochemical characterization of Venezuelan equine encephalitis virus (VEEV) nsP1. We have developed enzymatic assays uncoupling the different reactions steps catalyzed by nsP1. The MTase and GT reaction activities were followed using a nonhydrolyzable GTP (GIDP) substrate and an original Western blot assay using anti-m3G/m7G-cap monoclonal antibody, respectively. The GT reaction is stimulated by S-adenosyl-l-homocysteine (Ado-Hcy), the product of the preceding MTase reaction, and metallic ions. The covalent linking between nsP1 and m7GMP involves a phosphamide bond between the nucleotide and a histidine residue. Final guanylyltransfer onto RNA was observed for the first time with an alphavirus nsP1 using a 5′-diphosphate RNA oligonucleotide whose sequence corresponds to the 5′ end of the viral genome. Alanine scanning mutagenesis of residues H37, H45, D63, E118, Y285, D354, R365, N369, and N375 revealed their respective roles in MT and GT reactions. Finally, the inhibitory effects of sinefungin, aurintricarboxylic acid (ATA), and ribavirin triphosphate on MTase and capping reactions were investigated, providing possible avenues for antiviral research. IMPORTANCE Emergence or reemergence of alphaviruses represents a serious health concern, and the elucidation of their replication mechanisms is a prerequisite for the development of specific inhibitors targeting viral enzymes. In particular, alphaviruses are able, through an original reaction sequence, to add to their

  1. Ligand-mediated and tertiary interactions cooperatively stabilize the P1 region in the guanine-sensing riboswitch

    PubMed Central

    Hanke, Christian A.

    2017-01-01

    Riboswitches are genetic regulatory elements that control gene expression depending on ligand binding. The guanine-sensing riboswitch (Gsw) binds ligands at a three-way junction formed by paired regions P1, P2, and P3. Loops L2 and L3 cap the P2 and P3 helices and form tertiary interactions. Part of P1 belongs to the switching sequence dictating the fate of the mRNA. Previous studies revealed an intricate relationship between ligand binding and presence of the tertiary interactions, and between ligand binding and influence on the P1 region. However, no information is available on the interplay among these three main regions in Gsw. Here we show that stabilization of the L2-L3 region by tertiary interactions, and the ligand binding site by ligand binding, cooperatively influences the structural stability of terminal base pairs in the P1 region in the presence of Mg2+ ions. The results are based on molecular dynamics simulations with an aggregate simulation time of ~10 μs across multiple systems of the unbound state of the Gsw aptamer and a G37A/C61U mutant, and rigidity analyses. The results could explain why the three-way junction is a central structural element also in other riboswitches and how the cooperative effect could become contextual with respect to intracellular Mg2+ concentration. The results suggest that the transmission of allosteric information to P1 can be entropy-dominated. PMID:28640851

  2. C-Terminal nsP1a Protein of Human Astrovirus Colocalizes with the Endoplasmic Reticulum and Viral RNA

    PubMed Central

    Guix, Susana; Caballero, Santiago; Bosch, Albert; Pintó, Rosa M.

    2004-01-01

    Computational and biological approaches were undertaken to characterize the role of the human astrovirus nonstructural protein nsP1a/4, located at the C-terminal fragment of nsP1a. Computer analysis reveals sequence similarities to other nonstructural viral proteins involved in RNA replication and/or transcription and allows the identification of a glutamine- and proline-rich region, the prediction of many phosphorylation and O-glycosylation sites, and the occurrence of a KKXX-like endoplasmic reticulum retention signal. Immunoprecipitation analysis with an antibody against a synthetic peptide of the nsP1a/4 sequence detected polyprotein precursors of 160, 75, and 38 to 40 kDa as well as five smaller proteins in the range of 21 to 27 kDa. Immunofluorescence labeling showed that the nsP1a/4 protein is accumulated at the perinuclear region, in association with the endoplasmic reticulum and the viral RNA. These results suggest the involvement of nsP1a/4 protein in the RNA replication process in endoplasmic reticulum-derived intracellular membranes. PMID:15564473

  3. C-terminal nsP1a protein of human astrovirus colocalizes with the endoplasmic reticulum and viral RNA.

    PubMed

    Guix, Susana; Caballero, Santiago; Bosch, Albert; Pintó, Rosa M

    2004-12-01

    Computational and biological approaches were undertaken to characterize the role of the human astrovirus nonstructural protein nsP1a/4, located at the C-terminal fragment of nsP1a. Computer analysis reveals sequence similarities to other nonstructural viral proteins involved in RNA replication and/or transcription and allows the identification of a glutamine- and proline-rich region, the prediction of many phosphorylation and O-glycosylation sites, and the occurrence of a KKXX-like endoplasmic reticulum retention signal. Immunoprecipitation analysis with an antibody against a synthetic peptide of the nsP1a/4 sequence detected polyprotein precursors of 160, 75, and 38 to 40 kDa as well as five smaller proteins in the range of 21 to 27 kDa. Immunofluorescence labeling showed that the nsP1a/4 protein is accumulated at the perinuclear region, in association with the endoplasmic reticulum and the viral RNA. These results suggest the involvement of nsP1a/4 protein in the RNA replication process in endoplasmic reticulum-derived intracellular membranes.

  4. Residential characteristics predict changes in Der p 1, Fel d 1 and ergosterol but not fungi over time.

    PubMed

    Matheson, M C; Dharmage, S C; Forbes, A B; Raven, J M; Woods, R K; Thien, F C K; Guest, D I; Rolland, J M; Haydn Walters, E; Abramson, M J

    2003-09-01

    Allergen and fungal exposures are important risk factors for asthma. We conducted a longitudinal analysis of allergen levels in Melbourne homes between 1996 and 1998 to examine the effects of changing residential characteristics on allergen and fungal levels. We also examined the changes in levels of indoor allergens. The subjects were participants in the European Community Respiratory Health Survey (ECRHS) in Melbourne. In 1996, 485 subjects participated in a follow-up study, which involved both home and laboratory visits. Dust and air samples were collected from participants' bedrooms and a validated residential questionnaire was administered. In 1998, 360 participants underwent further follow-up. House dust mite (Der p 1) and cat allergens (Fel d 1) and ergosterol were measured in dust. We observed moderate within home correlations between 1996 and 1998 in floor Der p 1 (intraclass correlation ICC=0.48), bed Der p 1 (ICC=0.61), Fel d 1 (kappa=0.53) and ergosterol (ICC=0.28) levels. We found that the floor Der p 1 levels decreased from 1996 to 1998 in the homes of participants who moved to an attached home, moved their bedrooms to the first floor, removed fitted carpet or central heating. Replacing or vacuuming the mattress more than twice per year reduced levels of Der p 1 in the bed. Ergosterol levels were reduced by removing visible mould and fitted carpet. These findings provide evidence to support current advice with regard to allergen avoidance in patients with dust mite and fungal allergies.

  5. Photodynamics of blue-light-regulated phosphodiesterase BlrP1 protein from Klebsiella pneumoniae and its photoreceptor BLUF domain

    NASA Astrophysics Data System (ADS)

    Tyagi, A.; Penzkofer, A.; Griese, J.; Schlichting, I.; Kirienko, Natalia V.; Gomelsky, Mark

    2008-12-01

    The BlrP1 protein from the enteric bacterium Klebsiella pneumoniae consists of a BLUF and an EAL domain and may activate c-di-GMP phosphodiesterase by blue-light. The full-length protein, BlrP1, and its BLUF domain, BlrP1_BLUF, are characterized by optical absorption and emission spectroscopy. The cofactor FAD in its oxidized redox state (FAD ox) is brought from the dark-adapted receptor state to the 10-nm red-shifted putative signalling state by violet light exposure. The recovery to the receptor state occurs with a time constant of about 1 min. The quantum yield of signalling state formation is about 0.17 for BlrP1_BLUF and about 0.08 for BlrP1. The fluorescence efficiency of the FAD ox cofactor is small due to photo-induced reductive electron transfer. Prolonged light exposure converts FAD ox in the signalling state to the fully reduced hydroquinone form FAD redH - and causes low-efficient chromophore release with subsequent photo-degradation. The photo-cycle and photo-reduction dynamics in the receptor state and in the signalling state are discussed.

  6. Behavior of the P1.HTR mastocytoma cell line implanted in the chorioallantoic membrane of chick embryos.

    PubMed

    Avram, S F; Cimpean, A M; Raica, M

    2013-01-01

    The P1.HTR cell line includes highly transfectable cells derived from P815 mastocytoma cells originating from mouse breast tissue. Despite its widespread use in immunogenic studies, no data are available about the behavior of P1.HTR cells in the chick embryo chorioallantoic membrane model. The objective of the present investigation was to study the effects of P1.HTR cells implanted on the chorioallantoic membrane of chick embryos. We inoculated P1.HTR cells into the previously prepared chick embryo chorioallantoic membrane and observed the early and late effects of these cells by stereomicroscopy, histochemistry and immunohistochemistry. A highly angiotropic and angiogenic effect occurred early after inoculation and a tumorigenic potential with the development of mastocytoma keeping well mast cells immunophenotype was detected later during the development. The P1.HTR mastocytoma cell line is a good tool for the development of the chick embryo chorioallantoic membrane mastocytoma model and also for other studies concerning the involvement of blood vessels. The chick embryo chorioallantoic membrane model of mastocytoma retains the mast cell immunophenotype under experimental conditions and could be used as an experimental tool for in vivo preliminary testing of antitumor and antivascular drugs.

  7. WSF-P-1, a novel AMPK activator, promotes adiponectin multimerization in 3T3-L1 adipocytes.

    PubMed

    Wang, Yao; Zhang, Yudian; Wang, Yunyun; Peng, Han; Rui, Jian; Zhang, Zhijie; Wang, Shifa; Li, Zhen

    2017-08-01

    Adiponectin, an adipokine with insulin-sensitizing effect, is secreted from adipocytes into circulation as high, medium, and low molecular weight forms (HMW, MMW, and LMW). The HMW adiponectin oligomers possess the most potent insulin-sensitizing activity. WSF-P-1(N-methyl-1,2,3,4,5,6-hexahydro-1,1,5,5-tetramethyl-7H-2,4α-methanonaphthalen-7-amine) is derived from natural sesquiterpene longifolene by chemical modifications. We found that WSF-P-1 activates AMPK in both 3T3-L1 adipocytes and 293T cells in this study. Activation of AMPK by WSF-P-1 promotes the assembly of HMW adiponectin and increases the HMW/total ratio of adiponectin in 3T3-L1 adipocytes. We demonstrated that the Ca(2+)-dependent CaMKK signaling pathway is involved in WSF-P-1-induced AMPK activation and adiponectin multimerization. WSF-P-1 also activates GLUT1-mediated glucose uptake in 3T3-L1 adipocytes, making it a potential drug candidate for the treatment of type 2 diabetes, obesity, and other obesity-related metabolic diseases.

  8. Optimization of hydrothermal synthesis of pure phase zeolite Na-P1 from South African coal fly ashes.

    PubMed

    Musyoka, Nicholas M; Petrik, Leslie F; Gitari, Wilson M; Balfour, Gillian; Hums, Eric

    2012-01-01

    This study was aimed at optimizing the synthesis conditions for pure phase zeolite Na-P1 from three coal fly ashes obtained from power stations in the Mpumalanga province of South Africa. Synthesis variables evaluated were: hydrothermal treatment time (12-48 hours), temperature (100-160°C) and varying molar quantities of water during the hydrothermal treatment step (H(2)O:SiO(2) molar ratio ranged between 0-0.49). The optimum synthesis conditions for preparing pure phase zeolite Na-P1 were achieved when the molar regime was 1 SiO(2): 0.36 Al(2)O(3): 0.59 NaOH: 0.49 H(2)O and ageing was done at 47°C for 48 hours. The optimum hydrothermal treatment time and temperature was 48 hours and 140°C, respectively. Fly ashes sourced from two coal-fired power plants (A, B) were found to produce nearly same high purity zeolite Na-P1 under identical conditions whereas the third fly ash (C) lead to a low quality zeolite Na-P1 under these conditions. The cation exchange capacity for the high pure phase was found to be 4.11 meq/g. These results highlight the fact that adjustment of reactant composition and presynthesis or synthesis parameters, improved quality of zeolite Na-P1 can be achieved and hence an improved potential for application of zeolites prepared from coal fly ash.

  9. Interaction of Biliverdin Chromophore with Near-Infrared Fluorescent Protein BphP1-FP Engineered from Bacterial Phytochrome

    PubMed Central

    Stepanenko, Olesya V.; Stepanenko, Olga V.; Kuznetsova, Irina M.; Shcherbakova, Daria M.; Verkhusha, Vladislav V.; Turoverov, Konstantin K.

    2017-01-01

    Near-infrared (NIR) fluorescent proteins (FPs) designed from PAS (Per-ARNT-Sim repeats) and GAF (cGMP phosphodiesterase/adenylate cyclase/FhlA transcriptional activator) domains of bacterial phytochromes covalently bind biliverdin (BV) chromophore via one or two Cys residues. We studied BV interaction with a series of NIR FP variants derived from the recently reported BphP1-FP protein. The latter was engineered from a bacterial phytochrome RpBphP1, and has two reactive Cys residues (Cys15 in the PAS domain and Cys256 in the GAF domain), whereas its mutants contain single Cys residues either in the PAS domain or in the GAF domain, or no Cys residues. We characterized BphP1-FP and its mutants biochemically and spectroscopically in the absence and in the presence of denaturant. We found that all BphP1-FP variants are monomers. We revealed that spectral properties of the BphP1-FP variants containing either Cys15 or Cys256, or both, are determined by the covalently bound BV chromophore only. Consequently, this suggests an involvement of the inter-monomeric allosteric effects in the BV interaction with monomers in dimeric NIR FPs, such as iRFPs. Likely, insertion of the Cys15 residue, in addition to the Cys256 residue, in dimeric NIR FPs influences BV binding by promoting the BV chromophore covalent cross-linking to both PAS and GAF domains. PMID:28481303

  10. DNA looping-dependent autorepression of LEE1 P1 promoters by Ler in enteropathogenic Escherichia coli (EPEC)

    PubMed Central

    Bhat, Abhayprasad; Shin, Minsang; Jeong, Jae-Ho; Kim, Hyun-Ju; Lim, Hyung-Ju; Rhee, Joon Haeng; Paik, Soon-Young; Takeyasu, Kunio; Tobe, Toru; Yen, Hilo; Lee, Gwangrog; Choy, Hyon E.

    2014-01-01

    Ler, a homolog of H-NS in enteropathogenic Escherichia coli (EPEC), plays a critical role in the expression of virulence genes encoded by the pathogenic island, locus of enterocyte effacement (LEE). Although Ler acts as an antisilencer of multiple LEE operons by alleviating H-NS–mediated silencing, it represses its own expression from two LEE1 P1 promoters, P1A and P1B, that are separated by 10 bp. Various in vitro biochemical methods were used in this study to elucidate the mechanism underlying transcription repression by Ler. Ler acts through two AATT motifs, centered at position −111.5 on the coding strand and at +65.5 on the noncoding strand, by simultaneously repressing P1A and P1B through DNA-looping. DNA-looping was visualized using atomic force microscopy. It is intriguing that an antisilencing protein represses transcription, not by steric exclusion of RNA polymerase, but by DNA-looping. We propose that the DNA-looping prevents further processing of open promoter complex (RPO) at these promoters during transcription initiation. PMID:24920590

  11. Ac insertion site affects the frequency of transposon-induced homologous recombination at the maize p1 locus.

    PubMed Central

    Xiao, Y L; Li, X; Peterson, T

    2000-01-01

    The maize p1 gene regulates the production of a red pigment in the kernel pericarp, cob, and other maize floral tissues. Insertions of the transposable element Ac can induce recombination between two highly homologous 5.2-kb direct repeat sequences that flank the p1 gene-coding region. Here, we tested the effects of the Ac insertion site and orientation on the induction of recombination at the p1 locus. A collection of unique p1 gene alleles was used, which carry Ac insertions at different sites in and near the p1 locus, outside of the direct repeats, within the direct repeat sequences, and between the direct repeats, in both orientations. Recombination was scored by the numbers of colorless pericarp sectors (somatic frequency) and heritable mutations (germinal frequency). In both the somatic and germinal tests, the frequency of homologous recombination is significantly higher when Ac is inserted between the direct repeats than when Ac is inserted either within or outside the repeats. In contrast, Ac orientation had no significant effect on recombination frequency. We discuss these results in terms of the possible mechanisms of transposon-induced recombination. PMID:11102391

  12. Staphylococcus aureus exhibit similarities in their interactions with Acanthamoeba and ThP1 macrophage-like cells.

    PubMed

    Cardas, Mihaela; Khan, Naveed Ahmed; Alsam, Selwa

    2012-12-01

    Staphylococcus aureus is a leading cause of nosocomial infections. Haematogenous spread is a pre-requisite but it is not clear how S. aureus survive the onslaught of macrophages. Acanthamoeba is a protozoan pathogen that is remarkably similar to macrophages, particularly in their cellular structure (morphological and ultra-structural features), molecular motility, biochemical physiology, ability to capture prey by phagocytosis and interactions with microbial pathogens. Thus, we hypothesize that S. aureus exhibit similarities in their interactions with Acanthamoeba and ThP1 macrophage-like cells. Here, we studied interactions of methicillin-sensitive S. aureus (MSSA), methicillin-resistant S. aureus (MRSA) and Staphylococcus epidermidis (SE) with Acanthamoeba castellanii belonging to the T4 genotype and macrophage-like cells (ThP1). The findings revealed that both MRSA and MSSA exhibited similarities in their binding/association and invasion of A. castellanii and ThP1 cells. Long-term incubation showed that MRSA and MSSA can survive intracellularly of both Acanthamoeba and ThP1 cells. Overall, these findings suggest that Acanthamoeba exhibit similar characteristics with ThP1 macrophage-like cells in their interaction with MRSA and MSSA. Additionally it was shown that bacteria survive inside Acanthamoeba during the encystment process as evidenced by bacterial recovery from mature cysts. Given that Acanthamoeba cysts are airborne, these findings suggest that cysts may act as "Trojan horse" to help spread MRSA to susceptible hosts.

  13. P1 and P2 components of human visual evoked potentials are modulated by depth perception of 3-dimensional images.

    PubMed

    Omoto, Shu; Kuroiwa, Yoshiyuki; Otsuka, Saika; Baba, Yasuhisa; Wang, Chuanwei; Li, Mei; Mizuki, Nobuhisa; Ueda, Naohisa; Koyano, Shigeru; Suzuki, Yume

    2010-03-01

    To determine the cerebral activity correlated with depth perception of 3-dimensional (3D) images, by recording of human visual evoked potentials (VEPs). Two figures consisting of smaller and larger squares were presented alternately. VEPs were recorded in two conditions. In condition I, we used two figures which yielded flat 2-dimensional images. In condition II, we used two figures which yielded 3D images, which were concave and convex, respectively. P1, P2, and N1/P2 amplitude were significantly greater in condition II than in condition I. The P1/N1 amplitude tended to be greater in condition II than in condition I. P1 and N1 were predominantly distributed over the right temporo-parieto-occipital regions. P2 and N2 were distributed over bilateral parieto-occipital regions. The difference in P1 amplitude between two conditions can be explained by the difference between conditions, one of which yielded depth perception while the other did not, since previous studies showed that P1 and N1 are modulated by perception of images in depth. The role of P2 and the mechanism responsible for the increase in P2 amplitude during condition II remain unknown. We recorded VEPs and identified electrophysiological correlates of depth perception with 3D images produced by concave/convex figures.

  14. Fractal model of anomalous diffusion.

    PubMed

    Gmachowski, Lech

    2015-12-01

    An equation of motion is derived from fractal analysis of the Brownian particle trajectory in which the asymptotic fractal dimension of the trajectory has a required value. The formula makes it possible to calculate the time dependence of the mean square displacement for both short and long periods when the molecule diffuses anomalously. The anomalous diffusion which occurs after long periods is characterized by two variables, the transport coefficient and the anomalous diffusion exponent. An explicit formula is derived for the transport coefficient, which is related to the diffusion constant, as dependent on the Brownian step time, and the anomalous diffusion exponent. The model makes it possible to deduce anomalous diffusion properties from experimental data obtained even for short time periods and to estimate the transport coefficient in systems for which the diffusion behavior has been investigated. The results were confirmed for both sub and super-diffusion.

  15. Turbo fluid machinery and diffusers

    NASA Technical Reports Server (NTRS)

    Sakurai, T.

    1984-01-01

    The general theory behind turbo devices and diffusers is explained. Problems and the state of research on basic equations of flow and experimental and measuring methods are discussed. Conventional centrifugation-type compressor and fan diffusers are considered in detail.

  16. Amosphous diffusion barriers

    NASA Technical Reports Server (NTRS)

    Kolawa, E.; So, F. C. T.; Nicolet, M-A.

    1986-01-01

    Amorphous W-Zr and W-N alloys were investigated as diffusion barriers in silicon metallization schemes. Data were presented showing that amorphous W-Zr crystallizes at 900 C, which is 200 C higher than amorphous W-Ni films, and that both films react with metallic overlayers at temperatures far below the crystllization temperature. Also, W-N alloys (crystalline temperature of 600 C) were successfully incorporated as a diffusion barrier in contact structures with both Al and Ag overlayers. The thermal stability of the electrical characteristics of shallow n(+)p junctions significantly improved by incorporating W-N layers in the contact system. One important fact demonstated was the critical influence of the deposition parameters during formation of these carriers.

  17. Orientability and Diffusion Maps

    PubMed Central

    Singer, Amit; Wu, Hau-tieng

    2010-01-01

    One of the main objectives in the analysis of a high dimensional large data set is to learn its geometric and topological structure. Even though the data itself is parameterized as a point cloud in a high dimensional ambient space ℝp, the correlation between parameters often suggests the “manifold assumption” that the data points are distributed on (or near) a low dimensional Riemannian manifold ℳd embedded in ℝp, with d ≪ p. We introduce an algorithm that determines the orientability of the intrinsic manifold given a sufficiently large number of sampled data points. If the manifold is orientable, then our algorithm also provides an alternative procedure for computing the eigenfunctions of the Laplacian that are important in the diffusion map framework for reducing the dimensionality of the data. If the manifold is non-orientable, then we provide a modified diffusion mapping of its orientable double covering. PMID:21765628

  18. Diffusion in Immiscible Melts

    NASA Technical Reports Server (NTRS)

    Pond, R. B.

    1985-01-01

    The objective of this program is to measure the diffusion coefficients for molten Pb in Zn in the immiscible liquid-phase region. Diffusion couples of pure Pb and Zn were prepared using a shear cell. These have been placed in graphite crucibles and encapsulated in stainless steel cartridges and are awaiting the next Materials Experiment Assembly (MEA) flight opportunity. In flight, one couple will be soaked for 40 minutes at 440 deg C (just above the monotectic temperature) and the second couple will be soaked for 40 minutes 820 deg C (just above the consolute temperature). After the soak both samples will be rapidly quenched by flowing He to minimize redistribution of the immiscible phases. Post flight compositional analysis will be accomplished using X-ray fluorescence in the scanning electron microscopy.

  19. Diffusion tensor imaging.

    PubMed

    Jones, Derek K; Leemans, Alexander

    2011-01-01

    Diffusion tensor MRI (DT-MRI) is the only non-invasive method for characterising the microstructural organization of tissue in vivo. Generating parametric maps that help to visualise different aspects of the tissue microstructure (mean diffusivity, tissue anisotropy and dominant fibre orientation) involves a number of steps from deciding on the optimal acquisition parameters on the scanner, collecting the data, pre-processing the data and fitting the model to generating final parametric maps for entry into statistical data analysis. Here, we describe an entire protocol that we have used on over 400 subjects with great success in our laboratory. In the 'Notes' section, we justify our choice of the various parameters/choices along the way so that the reader may adapt/modify the protocol to their own time/hardware constraints.

  20. Magnetic diffuse scattering

    SciTech Connect

    Cable, J.W.

    1987-01-01

    The diffuse scattering of neutrons from magnetic materials provides unique and important information regarding the spatial correlations of the atoms and the spins. Such measurements have been extensively applied to magnetically ordered systems, such as the ferromagnetic binary alloys, for which the observed correlations describe the magnetic moment fluctuations associated with local environment effects. With the advent of polarization analysis, these techniques are increasingly being applied to study disordered paramagnetic systems such as the spin-glasses and the diluted magnetic semiconductors. The spin-pair correlations obtained are essential in understanding the exchange interactions of such systems. In this paper, we describe recent neutron diffuse scattering results on the atom-pair and spin-pair correlations in some of these disordered magnetic systems. 56 refs.

  1. Nonlocal electrical diffusion equation

    NASA Astrophysics Data System (ADS)

    Gómez-Aguilar, J. F.; Escobar-Jiménez, R. F.; Olivares-Peregrino, V. H.; Benavides-Cruz, M.; Calderón-Ramón, C.

    2016-07-01

    In this paper, we present an analysis and modeling of the electrical diffusion equation using the fractional calculus approach. This alternative representation for the current density is expressed in terms of the Caputo derivatives, the order for the space domain is 0<β≤1 and for the time domain is 0<γ≤2. We present solutions for the full fractional equation involving space and time fractional derivatives using numerical methods based on Fourier variable separation. The case with spatial fractional derivatives leads to Levy flight type phenomena, while the time fractional equation is related to sub- or super diffusion. We show that the mathematical concept of fractional derivatives can be useful to understand the behavior of semiconductors, the design of solar panels, electrochemical phenomena and the description of anomalous complex processes.

  2. [The diffusion of knowledge].

    PubMed

    Ramiro-H, Manuel; Cruz-A, Enrique

    2016-01-01

    Between August 19 and 21, the Feria del Libro de las Ciencias de la Salud (Healthcare Book Fair) took place in the Palacio de Medicina in Mexico City. Archives of Medical Research, Revista Médica del IMSS, and Saber IMSS, three of the main instruments of knowledge diffusion of the Instituto Mexicano del Seguro Social, assisted to this book fair, which was organized by the Facultad de Medicina of UNAM.

  3. Diffusive Shock Acceleration

    NASA Astrophysics Data System (ADS)

    Baring, Matthew

    2003-04-01

    The process of diffusive acceleration of charged particles in shocked plasmas is widely invoked in astrophysics to account for the ubiquitous presence of signatures of non-thermal relativistic electrons and ions in the universe. This statistical energization mechanism, manifested in turbulent media, was first posited by Enrico Fermi in 1949 to explain the observed cosmic ray population, which exhibits an almost power-law distribution in rigidity. The absence of a momentum scale is a key characteristic of diffusive shock acceleration, and astrophysical systems generally only impose scales at the injection (low energy) and loss (high energy) ends of the particle spectrum. The existence of structure in the cosmic ray spectrum (the "knee") at around 3000 TeV has promoted contentions that there are at least two origins for cosmic rays, a galactic one supplying those up to the knee, and perhaps an extragalactic one that can explain even the ultra-high energy cosmic rays (UHECRs) seen at 1-300 EeV. Accounting for the UHECRs with familiar astrophysical sites of acceleration has historically proven difficult due to the need to assume high magnetic fields in order to reduce the shortest diffusive acceleration timescale, the ion gyroperiod, to meaningful values. Yet active galaxies and gamma-ray bursts remain strong and interesting candidate sources for UHECRs, turning the theoretical focus to relativistic shocks. This review summarizes properties of diffusive shock acceleration that are salient to the issue of UHECR generation. These include spectral indices, anisotropies, acceleration efficencies and timescales, as functions of the shock speed and mean field orientation, and also the degree of field turbulence. Astrophysical sites for UHECR production are also critiqued.

  4. Peridynamic thermal diffusion

    SciTech Connect

    Oterkus, Selda; Madenci, Erdogan; Agwai, Abigail

    2014-05-15

    This study presents the derivation of ordinary state-based peridynamic heat conduction equation based on the Lagrangian formalism. The peridynamic heat conduction parameters are related to those of the classical theory. An explicit time stepping scheme is adopted for numerical solution of various benchmark problems with known solutions. It paves the way for applying the peridynamic theory to other physical fields such as neutronic diffusion and electrical potential distribution.

  5. The ThermalDiffusion class

    SciTech Connect

    Dolan, Daniel H.

    2014-10-01

    The ThermalDiffusion class was created to simulate one-dimensional thermal diffusion across one or more material layers. Each layer is assumed to have constant conductivity K and diffusivity κ . Interface conductance between layers may be specified. Internal heating as a function of position and time is also supported. The ThermalDiffusion class is included in the SMASH package [1] as part of the PDE (Partial Differential Equation) subpackage.

  6. Solute diffusion in liquid metals

    NASA Technical Reports Server (NTRS)

    Bhat, B. N.

    1973-01-01

    A gas model of diffusion in liquid metals is presented. In this model, ions of liquid metals are assumed to behave like the molecules in a dense gas. Diffusion coefficient of solute is discussed with reference to its mass, ionic size, and pair potential. The model is applied to the case of solute diffusion in liquid silver. An attempt was made to predict diffusion coefficients of solutes with reasonable accuracy.

  7. Double Diffusive Plumes

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Lee, Brace

    2008-11-01

    Sour gas flares attempt to dispose of deadly H2S gas through combustion. What does not burn rises as a buoyant plume. But the gas is heavier than air at room temperature, so as the rising gas cools eventually it becomes negatively buoyant and descends back to the ground. Ultimately, our intent is to predict the concentrations of the gas at ground level in realistic atmospheric conditions. As a first step towards this goal we have performed laboratory experiments examining the structure of a steady state plume of hot and salty water that rises buoyantly near the source and descends as a fountain after it has cooled sufficiently. We call this a double-diffusive plume because its evolution is dictated by the different (turbulent) diffusivities of heat and salt. A temperature and conductivity probe measures both the salinity and temperature along the centreline of the plume. The supposed axisymmetric structure of the salinity concentration as it changes with height is determined by light-attenuation methods. To help interpret the results, a theory has been successfully adapted from the work of Bloomfield and Kerr (2000), who developed coupled equations describing the structure of fountains. Introducing a new empirical parameter for the relative rates of turbulent heat and salt diffusion, the predictions are found to agree favourably with experimental results.

  8. P(1B)-ATPases--an ancient family of transition metal pumps with diverse functions in plants.

    PubMed

    Williams, Lorraine E; Mills, Rebecca F

    2005-10-01

    P(1B)-ATPases form a distinct evolutionary sub-family of P-type ATPases, transporting transition metals such as Cu, Zn, Cd, Pb and Co across membranes in a wide range of organisms, including plants. Structurally they are distinct from other P-types, possessing eight transmembrane helices, a CPx/SPC motif in transmembrane domain six, and putative transition metal-binding domains at the N- and/or C-termini. Arabidopsis has eight P(1B)-ATPases (AtHMA1-AtHMA8), which differ in their structure, function and regulation. They perform a variety of important physiological tasks relating to transition metal transport and homeostasis. The crucial roles of plant P(1B)-ATPases in micronutrient nutrition, delivery of essential metals to target proteins, and toxic metal detoxification are discussed.

  9. The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b

    NASA Astrophysics Data System (ADS)

    Winn, Joshua N.; Holman, Matthew J.; Bakos, Gaspar Á.; Pál, András; Johnson, John Asher; Williams, Peter K. G.; Shporer, Avi; Mazeh, Tsevi; Fernandez, José; Latham, David W.; Gillon, Michael

    2007-10-01

    We present photometry of the G0 star HAT-P-1 during six transits of its close-in giant planet, and we refine the estimates of the system parameters. Relative to Jupiter's properties, HAT-P-1b is 1.20 ± 0.05 times larger, and its surface gravity is 2.7 ± 0.2 times weaker. Although it remains the case that HAT-P-1b is among the least dense of the known sample of transiting exoplanets, its properties are in accord with previously published models of strongly irradiated, coreless, solar-composition giant planets. The times of the transits have a typical accuracy of 1 minute and do not depart significantly from a constant period.

  10. Uncovering the uncertainty: Risk factors and clinical relevance of P1 lesions on small bowel capsule endoscopy of anemic patients

    PubMed Central

    Cúrdia Gonçalves, Tiago; Barbosa, Mara; Rosa, Bruno; Moreira, Maria João; Cotter, José

    2016-01-01

    AIM To identify risk factors for P1 lesions on small bowel capsule endoscopy (SBCE) and to describe the natural history of anemic patients with such type of lesions. METHODS One hundred patients were consecutively selected for a case-control analysis performed between 37 cases with P1 lesions and 63 controls with negative SBCE. Age, gender, comorbidities and regular medication were collected. Rebleeding, further investigational studies and death were also analyzed during the follow-up. RESULTS No significant differences on gender, median age or Charlson index were found between groups. Although no differences were found on the use of proton pump inhibitors, acetylsalicylic acid, anticoagulants or antiplatelet agents, the use of non-steroidal anti-inflammatory drugs (NSAID) was associated with a higher risk of P1 lesions (OR = 12.00, 95%CI: 1.38-104.1). From the 87 patients followed at our center, 39 were submitted to additional studies for investigation of iron-deficiency anemia (IDA), and this was significantly more common in those patients with no findings on SBCE (53.7% vs 30.3%, P = 0.033). A total of 29 patients had at least one rebleeding or IDA recurrence episode and 9 patients died of non-anemia related causes but no differences were found between cases and controls. CONCLUSION P1 lesions are commonly found in patients with IDA submitted to SBCE. The use of NSAID seems to be a risk factor for P1 lesions. The outcomes of patients with P1 lesions do not differ significantly from those with P0 lesions or normal SBCE. PMID:27784969

  11. Structural differences between Saccharomyces cerevisiae ribosomal stalk proteins P1 and P2 support their functional diversity.

    PubMed

    Zurdo, J; González, C; Sanz, J M; Rico, M; Remacha, M; Ballesta, J P

    2000-08-01

    The eukaryotic acidic P1 and P2 proteins modulate the activity of the ribosomal stalk but playing distinct roles. The aim of this work was to analyze the structural features that are behind their different function. A structural characterization of Saccharomyces cerevisaie P1 alpha and P2 beta proteins was performed by circular dichroism, nuclear magnetic resonance, fluorescence spectroscopy, thermal denaturation, and protease sensitivity. The results confirm the low structure present in both proteins but reveal clear differences between them. P1 alpha shows a virtually unordered secondary structure with a residual helical content that disappears below 30 degrees C and a clear tendency to acquire secondary structure at low pH and in the presence of trifluoroethanol. In agreement with this higher disorder P1 alpha has a fully solvent-accessible tryptophan residue and, in contrast to P2 beta, is highly sensitive to protease degradation. An interaction between both proteins was observed, which induces an increase in the global secondary structure content of both proteins. Moreover, mixing of both proteins causes a shift of the P1 alpha tryptophan 40 signal, pointing to an involvement of this region in the interaction. This evidence directly proves an interaction between P1 alpha and P2 beta before ribosome binding and suggests a functional complementation between them. On a whole, the results provide structural support for the different functional roles played by the proteins of the two groups showing, at the same time, that relatively small structural differences between the two stalk acidic protein types can result in significant functional changes.

  12. Genetic rescue of segmentation defect in MesP2-deficient mice by MesP1 gene replacement.

    PubMed

    Saga, Y

    1998-07-01

    Gene knock-out and knock-in strategies are employed to investigate the function of MesP1. MesP1 belongs to the same family of bHLH transcription factors as MesP2. The early expression pattern observed in the early mesoderm at the onset of gastrulation is restricted to Mesp1, while the later expression pattern in the anterior presomitic mesoderm during somitogenesis is almost the same for Mesp1 as for Mesp2. Homozygous Mesp1 null mice exhibited growth retardation after 7.5 dpc and died before 10.5 dpc with many developmental defects. The function of MesP1 during somitogenesis was not clearly revealed because of their early death and the possible compensation by MesP2. In order to examine the functions of MesP1 during somitogenesis, we replaced the Mesp2 gene with Mesp1 cDNA, using a gene knock-in strategy. The introduced Mesp1 cDNA could rescue the defects caused by Mesp2 deficiency in a dosage-dependent manner. Mice which lacked Mesp2 expression but had four copies of the Mesp1 gene survived into the adulthood and were fertile. The skeletal defects and the reduction in expression of Notch1, Notch2 and FGFR-1 previously observed in Mesp2 null mice were almost completely rescued by the introduced MesP1. Thus, it is concluded that the functions of MesP1 during somitogenesis, like MesP2, are also mediated via notch-delta and FGF signaling systems.

  13. Dissolution kinetics of synthetic zeolite NaP1 and its implication to zeolite treatment of contaminated waters.

    PubMed

    Cama, Jordi; Ayora, Carles; Querol, Xavier; Ganor, Jiwchar

    2005-07-01

    The effect of pH on the dissolution kinetics of NaP1 zeolite, which was produced from the alkaline treatment of coal fly ash and may be used for decontamination of acid mine waters, is studied. The sample contains considerable amounts of accessory phases that partly dissolve during the experiment. Therefore, the dissolution rate was estimated during a stage in which the Al/Si ratio was equal to that of NaP1 (0.6). The release rate of these elements is controlled by the dissolution of the zeolite itself during this stage. The dissolution rate of NaP1 slows down with increasing pH in the acidic range, becomes constant at an intermediate pH, and increases with increasing pH in the basic range. The observed changes in rates were described using a rate law based on a surface speciation model. Using this rate law, we calculated the half-life of NaP1 to be about 2 years at near neutral pH and less than 10 days at pH below 3. For the utilization of NaP1 in the treatment of wastewaters or acid mine waters, these short half-lives bear two implications: (1) The treated waters must be kept at near neutral pH, and NaP1 should be added periodically to the treated waters in order to compensate for zeolite loss. (2) In water treatment applications that require a relatively short reaction time, the zeolite removed from the effluents should be kept dry in order to avoid its decomposition and the consequent release of the adsorbed metal to the environment.

  14. Evaluation of the Eological Management and Enhancement Alernative for Remediation of the K1007-P1 Pond

    SciTech Connect

    Peterson, M.J.

    2005-10-31

    An evaluation of the human and ecological risks associated with the P1 Pond and surrounding environs was conducted as part of the ETTP Site-Wide Remedial Investigation. The RI provides the basis for the focus on PCBs as the most important unacceptable risk to human and ecological health in the pond. Other P1 contaminants, media, or pathways of risk to receptors are identified in the RI, but are not addressed as a major risk reduction goal for the ETTP Site-Wide Feasibility Study. Therefore, the goal of the Ecological Management alternative is to reduce unacceptable risks associated with PCBs in fish. Many of the actions proposed for this alternative, however, are likely to reduce risks associated with other contaminants and their pathways. The high PCB concentrations in fish from the P1 Pond are most certainly due in part to the current ecological condition of the pond that maximizes PCB biomagnification. This basic assumption and the factors contributing to it were evaluated by conducting an intensive field study of the P1 Pond in the summer of 2004 (for a thorough presentation of current P1 Pond biological conditions, see Peterson et al. 2005). Major hypotheses regarding the P1 Pond's current fish community, PCB fate and transport processes, pond vegetation, and limnological conditions that contribute to the high PCB levels in fish were validated by the study (Appendix A), The results of the 2004 ecological assessment, in concert with long-term datasets obtained as part of the ETTP Biological Monitoring and Abatement Program (BMAP) and recent abiotic sampling for the RI, provide the basis for the assessment of current conditions.

  15. Discovery of oxazole and triazole derivatives as potent and selective S1P(1) agonists through pharmacophore-guided design.

    PubMed

    Tian, Yulin; Jin, Jing; Wang, Xiaojian; Hu, Jinping; Xiao, Qiong; Zhou, Wanqi; Chen, Xiaoguang; Yin, Dali

    2014-10-06

    We have discovered a series of triazole/oxazole-containing 2-substituted 2-aminopropane-1,3-diol derivatives as potent and selective S1P1 agonists (prodrugs) based on pharmacophore-guided rational design. Most compounds showed high affinity and selectivity for S1P1 receptor. Compounds 19b, 19d and 19p displayed clear dose responsiveness in the lymphocyte reduction model when administered orally at doses of 0.3, 1.0, 3.0 mg/kg with reduced effect on heart rate. These three compounds were also identified to have favorable pharmacokinetic properties.

  16. Tryptophan pyrolysis products, Trp-P-1 and Trp-P-2 induce apoptosis in primary cultured rat hepatocytes.

    PubMed

    Ashida, H; Shiotani, B; Adachi, H; Hashimoto, T; Kanazawa, K; Danno, G

    1998-11-01

    The cytotoxicity of heterocyclic amines, dietary carcinogens derived from cooked foods, to primary cultured rat hepatocytes was studied. A tryptophan pyrolysis product, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) was the most cytotoxic of 11 compounds tested. Trp-P-1 was found to induce apoptosis as measured by morphological changes in nuclear chromatin and internucleosomal DNA fragmentation. 3-Amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) showed a moderate apoptotic effect, and other compounds had a similar but weaker effect.

  17. Isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions

    NASA Astrophysics Data System (ADS)

    Zubova, N. A.; Malyshev, A. V.; Tupitsyn, I. I.; Shabaev, V. M.; Kozhedub, Y. S.; Plunien, G.; Brandau, C.; Stöhlker, Th.

    2016-05-01

    Isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions are evaluated for a wide range of the nuclear charge number: Z =8 -92 . The calculations of the relativistic nuclear recoil and nuclear size effects are performed using a large-scale configuration-interaction Dirac-Fock-Sturm method. The corresponding QED corrections are also taken into account. The results of the calculations are compared with the theoretical values obtained with other methods. The accuracy of the isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions is significantly improved.

  18. Configurational diffusion of coal macromolecules

    SciTech Connect

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.

    1990-01-01

    The objective of this project is to investigate the phenomenon of hindered diffusion of coal macromolecules in idealized porous media. Tasks towards this objective include: Construct a diffusion cell with ideal pore structure for determination of diffusion coefficients, prepare and characterize ideal porous membranes, perform model compound experiments to calibrate and test diffusion apparatus and methodology, prepare and characterize coal macromolecules, and analyze data to evaluate the diffusional behavior of coal macromolecules. This report describes work on the hindered diffusion of tetraphenylporphine and asphaltene. 18 refs., 3 figs., 4 tabs.

  19. Particle diffusion in a spheromak

    SciTech Connect

    Meyerhofer, D.D.; Levinton, F.M.; Yamada, M.

    1988-01-01

    The local carbon particle diffusion coefficient was measured in the Proto S-1/C spheromak using a test particle injection scheme. When the plasma was not in a force-free Taylor state, and when there were pressure gradients in the plasma, the particle diffusion was five times that predicted by Bohm and was consistent with collisional drift wave diffusion. The diffusion appears to be driven by correlations of the fluctuating electric field and density. During the decay phase of the discharge when the plasma was in the Taylor state, the diffusion coefficient of the carbon was classical. 23 refs., 4 figs.

  20. Beltrami-McKeon-Schubert Realizations of fraktur ofraktur sfraktur p(1|4) Algebra and Possible Supersymmetric Kinematics

    NASA Astrophysics Data System (ADS)

    Li, Lin; Huang, Chao-Guang

    2015-07-01

    The possible supersymmetric kinematics are presented by the contraction method in different limits from Beltrami-McKeon-Schubert realizations of fraktur ofraktur sfraktur p(1|4). The connections among the superalgebras are established. The comparison with the superalgebras contracted from Beltrami-Ivanov-Sorini realization is made. Supported by National Natural Science Foundation of China under Grant No. 11275207

  1. Chemical Properties of Electronically Excited Halogen Atoms X(2P1/2) (X=F,Cl,Br,I)

    NASA Astrophysics Data System (ADS)

    Chichinin, A. I.

    2006-06-01

    The experimental data on elementary processes (collisional deactivation, chemical reactions, photodissociation) involving spin-orbitally excited X(2P1/2) atoms (X=F,Cl,Br,I) published up to the middle of 2005 are summarized in the present compilation. Critical evaluation of the data and limited comparison to theoretical calculations are also presented.

  2. Wheat streak mosaic virus P1: Defining the minimal region required for the suppression of RNA silencing activity

    USDA-ARS?s Scientific Manuscript database

    Wheat streak mosaic virus (WSMV) is the most economically important wheat virus in the Great Plains region of USA. WSMV is the type species of the genus Tritimovirus in the family Potyviridae, and is transmitted by the wheat curl mite, Aceria tosichella Keifer. Previously, we reported that WSMV P1 f...

  3. Quality Control of Fungus-specific Glucosylceramide in Cryptococcus neoformans by Endoglycoceramidase-related Protein 1 (EGCrP1)*

    PubMed Central

    Ishibashi, Yohei; Ikeda, Kazutaka; Sakaguchi, Keishi; Okino, Nozomu; Taguchi, Ryo; Ito, Makoto

    2012-01-01

    A fungus-specific glucosylceramide (GlcCer), which contains a unique sphingoid base possessing two double bonds and a methyl substitution, is essential for pathogenicity in fungi. Although the biosynthetic pathway of the GlcCer has been well elucidated, little is known about GlcCer catabolism because a GlcCer-degrading enzyme (glucocerebrosidase) has yet to be identified in fungi. We found a homologue of endoglycoceramidase tentatively designated endoglycoceramidase-related protein 1 (EGCrP1) in several fungal genomic databases. The recombinant EGCrP1 hydrolyzed GlcCer but not other glycosphingolipids, whereas endoglycoceramidase hydrolyzed oligosaccharide-linked glycosphingolipids but not GlcCer. Disruption of egcrp1 in Cryptococcus neoformans, a typical pathogenic fungus causing cryptococcosis, resulted in the accumulation of fungus-specific GlcCer and immature GlcCer that possess sphingoid bases without a methyl substitution concomitant with a dysfunction of polysaccharide capsule formation. These results indicated that EGCrP1 participates in the catabolism of GlcCer and especially functions to eliminate immature GlcCer in vivo that are generated as by-products due to the broad specificity of GlcCer synthase. We conclude that EGCrP1, a glucocerebrosidase identified for the first time in fungi, controls the quality of GlcCer by eliminating immature GlcCer incorrectly generated in C. neoformans, leading to accurate processing of fungus-specific GlcCer. PMID:22072709

  4. Open-complex formation by the host initiator, DnaA, at the origin of P1 plasmid replication.

    PubMed Central

    Mukhopadhyay, G; Carr, K M; Kaguni, J M; Chattoraj, D K

    1993-01-01

    Replication of P1 plasmid requires both the plasmid-specific initiator, RepA, and the host initiator, DnaA. Here we show that DnaA can make the P1 origin reactive to the single-strand specific reagents KMnO4 and mung bean nuclease. Addition of RepA further increased the KMnO4 reactivity of the origin, although RepA alone did not influence the reaction. The increased reactivity implies that the two initiators interact in some way to alter the origin conformation. The KMnO4 reactivity was restricted to one strand of the origin. We suggest that the roles of DnaA in P1 plasmid and bacterial replication are similar: origin opening and loading of the DnaB helicase. The strand-bias in chemical reactivity at the P1 origin most likely indicates that only one of the strands is used for the loading of DnaB, a scenario consistent with the unidirectional replication of the plasmid. Images PMID:8223464

  5. Distribution of the carcinogenic tryptophan pyrolysis product Trp-P-1 in control, 9-hydroxyellipticine and. beta. -naphthoflavone pretreated mice

    SciTech Connect

    Brandt, I. . Dept. of Pharmacology); Gustafsson, J.A.; Rafter, J. )

    1983-10-01

    Autoradiograms obtained 1-4 h after i.v. injection of the /sup 14/C-labelled carcinogenic tryptophan pyrolysis product Trp-P-1 to albino and pigmented mice showed a pronounced uptake of radioactivity in the lymphatic system, in the endocrine system and in the liver, kidney medulla and brain. High radioactivity was present in the excretory pathways, predominantly in the bile/intestinal contents. At longer post-injection times most of the labelled substance had left the tissues, except for the liver. Trp-P-1 is known to be activated by cytochrome P-448. The uptake of radioactivity in the liver could be reduced by pretreatment with the cytochrome P-448 inhibitor 9-hydroxyellipticine suggesting that the observed accumulation of radioactivity in the liver was partly due to metabolites of Trp-P-1. After pretreatment with the cytochrome P-448 inducer ..beta..-naphthoflavone, the administration of Trp-P-1 resulted in a highly selective accumulation of radioactivity in the lung parenchyma, exceeding all other tissues. ..beta..-Naphthoflavone pretreatment also increased the uptake of radioactivity in the kidney cortex and small intestinal mucosa. As indicated by a high labelling of the pigmented tissues of the maternal and fetal eye, the carcinogen and/or its metabolites were accumulated in melanin.

  6. Sphingosine-1-phosphate promotes lymphangiogenesis by stimulating S1P1/Gi/PLC/Ca2+ signaling pathways.

    PubMed

    Yoon, Chang Min; Hong, Bok Sil; Moon, Hyung Geun; Lim, Seyoung; Suh, Pann-Ghill; Kim, Yoon-Keun; Chae, Chi-Bom; Gho, Yong Song

    2008-08-15

    The lymphatic system plays pivotal roles in mediating tissue fluid homeostasis and immunity, and excessive lymphatic vessel formation is implicated in many pathological conditions, which include inflammation and tumor metastasis. However, the molecular mechanisms that regulate lymphatic vessel formation remain poorly characterized. Sphingosine-1-phosphate (S1P) is a potent bioactive lipid that is implicated in a variety of biologic processes such as inflammatory responses and angiogenesis. Here, we first report that S1P acts as a lymphangiogenic mediator. S1P induced migration, capillary-like tube formation, and intracellular Ca(2+) mobilization, but not proliferation, in human lymphatic endothelial cells (HLECs) in vitro. Moreover, a Matrigel plug assay demonstrated that S1P promoted the outgrowth of new lymphatic vessels in vivo. HLECs expressed S1P1 and S1P3, and both RNA interference-mediated down-regulation of S1P1 and an S1P1 antagonist significantly blocked S1P-mediated lymphangiogenesis. Furthermore, pertussis toxin, U73122, and BAPTA-AM efficiently blocked S1P-induced in vitro lymphangiogenesis and intracellular Ca(2+) mobilization of HLECs, indicating that S1P promotes lymphangiogenesis by stimulating S1P1/G(i)/phospholipase C/Ca(2+) signaling pathways. Our results suggest that S1P is the first lymphangiogenic bioactive lipid to be identified, and that S1P and its receptors might serve as new therapeutic targets against inflammatory diseases and lymphatic metastasis in tumors.

  7. Construction of intergeneric hybrids using bacteriophage P1CM: transfer of the Klebsiella aerogenes ribitol dehydrogenase gene to Escherichia coli.

    PubMed

    Rigby, P W; Gething, M J; Hartley, B S

    1976-02-01

    Study of many of the interesting properties of Klebsiella aerogenes is limited by the lack of a well-characterized genetic system for this organism. Our investigations of the evolution of the enzyme ribitol dehydrogenase (EC 1.1.1.56) in K. aerogenes would be greatly facilitated by the availability of such a system, and we here report two approaches to developing one. We have isolated mutants sensitive to the coliphage P1, which will efficiently tranduce genetic markers between such sensitive strains and which will thus make detailed mapping studies possible. Derivatives of K. aerogenes lysogenic for P1 can be readily isolated by using the specialized transducing particle P1CMclr100. Bacteria lysogenic for this phage are chloramphenicol resistant and temperature sensitive. Phage particles produced by temperature induction of such lysogens can be used to transfer K. aerogenes genes to the natural host of P1 phage. Escherichia coli. We have used this method to prepare derivatives of E. coli K-12 carrying the K. aerogenes genes conferring the ability to metabolize the pentitols ribitol and D-arabitol. We have shown that these E. coli-K. aerogenes hybrids synthesize a ribitol dehydrogenase with the properties of the K. aerogenes enzyme and have mapped the position of the transferred gene on the E. coli chromosome. The ramifications of this methodology are discussed.

  8. Leek yellow stripe virus isolates from Brazil form a distant clade based on the P1 gene

    USDA-ARS?s Scientific Manuscript database

    The complete genomic sequence of a garlic isolate of Leek yellow stripe virus from Brazil (LYSV-MG) has been determined, and phylogenetic comparisons made to LYSV isolates from other parts of the world. In addition, the nucleotide sequence of the 5'UTR and part of the P1 gene of multiple LYSV isolat...

  9. Nonanaphylactic synthetic peptides derived from B cell epitopes of the major grass pollen allergen, Phl p 1, for allergy vaccination.

    PubMed

    Focke, M; Mahler, V; Ball, T; Sperr, W R; Majlesi, Y; Valent, P; Kraft, D; Valenta, R

    2001-09-01

    Worldwide more than 200 million individuals are allergic to group 1 grass pollen allergens. We have used the major timothy grass pollen allergen Phl p 1, which cross-reacts with most grass-, corn-, and monocot-derived group 1 allergens to develop a generally applicable strategy for the production of hypoallergenic allergy vaccines. On the basis of the experimentally determined B cell epitopes of Phl p 1, we have synthesized five synthetic peptides. These peptides are derived from the major Phl p 1 IgE epitopes and were between 28-32 amino acids long. We demonstrate by nuclear magnetic resonance that the peptides exhibit no secondary and tertiary structure and accordingly failed to bind IgE antibodies from grass pollen allergic patients. The five peptides, as well as an equimolar mixture thereof, lacked allergenic activity as demonstrated by basophil histamine release and skin test experiments in grass pollen allergic patients. When used as immunogens in mice and rabbits, the peptides induced protective IgG antibodies, which recognized the complete Phl p 1 wild-type allergen and group 1 allergens from other grass species. Moreover, peptide-induced antibodies inhibited the binding of grass pollen allergic patients IgE antibodies to the wild-type allergen. We thus demonstrate that synthetic hypoallergenic peptides derived from B cell epitopes of major allergens represent safe vaccine candidates for the treatment of IgE- mediated allergies.

  10. Comparative Polarimetry of Comets 103P/Hartley 2, 9P/Tempel 1, and C/2009 P1 (Garradd)

    NASA Astrophysics Data System (ADS)

    Kiselev, N. N.; Rosenbush, V. K.; Afanasiev, V. L.; Blinov, D. A.; Kolesnikov, S. V.; Zaitsev, S. V.

    2012-05-01

    The results of polarimetry of comets 103P/Hartley 2 and 9P/Tempel 1 obtained during the EPOXI mission encounter and DEEP IMPACT mission respectively and comet C/2009 P1 (Garradd) during its approach to the Earth in 2011-2012 are presented.

  11. Role of dorsal root ganglion K2P1.1 in peripheral nerve injury-induced neuropathic pain

    PubMed Central

    Mao, Qingxiang; Yuan, Jingjing; Xiong, Ming; Wu, Shaogen; Chen, Liyong; Bekker, Alex; Yang, Tiande

    2017-01-01

    Peripheral nerve injury-caused hyperexcitability and abnormal ectopic discharges in the primary sensory neurons of dorsal root ganglion (DRG) play a key role in neuropathic pain development and maintenance. The two-pore domain background potassium (K2P) channels have been identified as key determinants of the resting membrane potential and neuronal excitability. However, whether K2P channels contribute to neuropathic pain is still elusive. We reported here that K2P1.1, the first identified mammalian K2P channel, was highly expressed in mouse DRG and distributed in small-, medium-, and large-sized DRG neurons. Unilateral lumbar (L) 4 spinal nerve ligation led to a significant and time-dependent reduction of K2P1.1 mRNA and protein in the ipsilateral L4 DRG, but not in the contralateral L4 or ipsilateral L3 DRG. Rescuing this reduction through microinjection of adeno-associated virus-DJ expressing full-length K2P1.1 mRNA into the ipsilateral L4 DRG blocked spinal nerve ligation-induced mechanical, thermal, and cold pain hypersensitivities during the development and maintenance periods. This DRG viral microinjection did not affect acute pain and locomotor function. Our findings suggest that K2P1.1 participates in neuropathic pain development and maintenance and may be a potential target in the management of this disorder. PMID:28326939

  12. HST/STIS Transmission Spectral Survey: Probing the Atmospheres of HAT-P-1b and WASP-6b

    NASA Astrophysics Data System (ADS)

    Nikolov, N.; Sing, D. K.; Pont, F.; Burrows, A. S.; Fortney, J. J.; Ballester, G. E.; Evans, T. M.; Huitson, C. M.; Wakeford, H. R.; Wilson, P. A.; A. D., S.; Gibson, N. P.; Henry, G. W.; Knutson, H.; Etangs, A. L. d.; Showman, A. P.; Vidal-Madjar, A.; Zahnle, K.

    2014-03-01

    We present optical to near-infrared transmission spectra of HAT-P-1b and WASP-6b, part of a Large HST/STIS hot Jupiter transmission spectral survey (P.I. David Sing). The spectra for each target cover the regimes 2900-5700Å and 5240-10270Å, with resolving power of R = 500. The HAT-P-1b data is coupled with a recent HST/WFC3 transit, spanning the wavelength range 1.087-1.687microns (R=130), acquired in spatial scan mode. The WASP-6b data is complemented with Spritzer/IRAC 3.6 and 4.5 micron transit observations, part of a comparative exoplanetology program (P.I. Jean-Michel Desert). The transmission spectrum of HAT-P-1b shows a strong absorption signature shortward of 5500Å, with a strong blueward slope into the near-UV. We detect atmospheric sodium absorption at a 3.3s significance level, but see no evidence for the potassium feature. The red data implies a marginally flat spectrum with a tentative absorption enhancement at wavelength longer than ~8500Å. The combined STIS and WFC3 optical to NIR spectra differ significantly in absolute radius level (4.3+/-1.6 pressure scale heights), implying strong optical absorption in the atmosphere of HAT-P-1b. The optical to nearinfrared difference cannot be explained by stellar activity, as simultaneous stellar activity monitoring of the G0V HAT-P-1b host star and its identical companion show no significant activity that could explain the result. The red transmission spectrum of WASP-6b is flat with tentative detection of sodium and potassium. We compare both spectra with theoretical atmospheric models, which include haze, sodium and an extra optical absorber in the case of HAT-P-1b. We find that both an optical absorber and a super-solar sodium to water abundance ratio might be a scenario explaining the HAT-P-1b observations.

  13. Transferable antibiotic resistance plasmids from biogas plant digestates often belong to the IncP-1ε subgroup.

    PubMed

    Wolters, Birgit; Kyselková, Martina; Krögerrecklenfort, Ellen; Kreuzig, Robert; Smalla, Kornelia

    2014-01-01

    Manure is known to contain residues of antibiotics administered to farm animals as well as bacteria carrying antibiotic resistance genes (ARGs). These genes are often located on mobile genetic elements. In biogas plants (BGPs), organic substrates such as manure and plant material are mixed and fermented in order to provide energy, and resulting digestates are used for soil fertilization. The fate of plasmid carrying bacteria from manure during the fermentation process is unknown. The present study focused on transferable antibiotic resistance plasmids from digestates of seven BGPs, using manure as a co-substrate, and their phenotypic and genotypic characterization. Plasmids conferring resistance to either tetracycline or sulfadiazine were captured by means of exogenous plasmid isolation from digestates into Pseudomonas putida KT2442 and Escherichia coli CV601 recipients, at transfer frequencies ranging from 10(-5) to 10(-7). Transconjugants (n = 101) were screened by PCR-Southern blot hybridization and real-time PCR for the presence of IncP-1, IncP-1ε, IncW, IncN, IncP-7, IncP-9, LowGC, and IncQ plasmids. While 61 plasmids remained unassigned, 40 plasmids belonged to the IncP-1ε subgroup. All these IncP-1ε plasmids were shown to harbor the genes tet(A), sul1, qacEΔ1, intI1, and integron gene cassette amplicons of different size. Further analysis of 16 representative IncP-1ε plasmids showed that they conferred six different multiple antibiotic resistance patterns and their diversity seemed to be driven by the gene cassette arrays. IncP-1ε plasmids displaying similar restriction and antibiotic resistance patterns were captured from different BGPs, suggesting that they may be typical of this environment. Our study showed that BGP digestates are a potential source of transferable antibiotic resistance plasmids, and in particular the broad host range IncP-1ε plasmids might contribute to the spread of ARGs when digestates are used as fertilizer.

  14. Transferable antibiotic resistance plasmids from biogas plant digestates often belong to the IncP-1ε subgroup

    PubMed Central

    Wolters, Birgit; Kyselková, Martina; Krögerrecklenfort, Ellen; Kreuzig, Robert; Smalla, Kornelia

    2015-01-01

    Manure is known to contain residues of antibiotics administered to farm animals as well as bacteria carrying antibiotic resistance genes (ARGs). These genes are often located on mobile genetic elements. In biogas plants (BGPs), organic substrates such as manure and plant material are mixed and fermented in order to provide energy, and resulting digestates are used for soil fertilization. The fate of plasmid carrying bacteria from manure during the fermentation process is unknown. The present study focused on transferable antibiotic resistance plasmids from digestates of seven BGPs, using manure as a co-substrate, and their phenotypic and genotypic characterization. Plasmids conferring resistance to either tetracycline or sulfadiazine were captured by means of exogenous plasmid isolation from digestates into Pseudomonas putida KT2442 and Escherichia coli CV601 recipients, at transfer frequencies ranging from 10-5 to 10-7. Transconjugants (n = 101) were screened by PCR-Southern blot hybridization and real-time PCR for the presence of IncP-1, IncP-1ε, IncW, IncN, IncP-7, IncP-9, LowGC, and IncQ plasmids. While 61 plasmids remained unassigned, 40 plasmids belonged to the IncP-1ε subgroup. All these IncP-1ε plasmids were shown to harbor the genes tet(A), sul1, qacEΔ1, intI1, and integron gene cassette amplicons of different size. Further analysis of 16 representative IncP-1ε plasmids showed that they conferred six different multiple antibiotic resistance patterns and their diversity seemed to be driven by the gene cassette arrays. IncP-1ε plasmids displaying similar restriction and antibiotic resistance patterns were captured from different BGPs, suggesting that they may be typical of this environment. Our study showed that BGP digestates are a potential source of transferable antibiotic resistance plasmids, and in particular the broad host range IncP-1ε plasmids might contribute to the spread of ARGs when digestates are used as fertilizer. PMID:25653641

  15. Diffusion in silicon isotope heterostructures

    SciTech Connect

    Silvestri, Hughes Howland

    2004-01-01

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and 28Si enriched layers, enables the observation of 30Si self-diffusion from the natural layers into the 28Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly

  16. Vapor Diffusion Apparatus

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Vapor Diffusion Apparatus (VDA and VDA-2) was developed by the University of Alabama in Birmingham for NASA's Marshall Space Flight Center. In the original VDA, a protein solution and a precipitant are extruded by two plungers onto the tip of a small syringe and allowed to evaporate, raising the concentration and prompting protein molecules to crystallize. In the VDA-2 version, a third plunger was added to mix the two solutions before returning the mix to the syringe tip. The principal investigator is Dr. Larry Delucas of the University of Alabama in Birmingham

  17. Vapor Diffusion Apparatus

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Vapor Diffusion Apparatus (VDA-2) was developed by the University of Alabama in Birmingham for NASA's Marshall Space Flight Center. In the original VDA, a protein solution and a precipitant are extruded by two plungers onto the tip of a small syringe and allowed to evaporate, raising the concentration and prompting protein molecules to crystallize. In the VDA-2 version, a third plunger was added to mix the two solutions before returning the mix to the syringe tip. The principal investigator is Dr. Larry Delucas of the University of Alabama in Birmingham.

  18. Diffusion in quantum geometry

    NASA Astrophysics Data System (ADS)

    Calcagni, Gianluca

    2012-08-01

    The change of the effective dimension of spacetime with the probed scale is a universal phenomenon shared by independent models of quantum gravity. Using tools of probability theory and multifractal geometry, we show how dimensional flow is controlled by a multiscale fractional diffusion equation, and physically interpreted as a composite stochastic process. The simplest example is a fractional telegraph process, describing quantum spacetimes with a spectral dimension equal to 2 in the ultraviolet and monotonically rising to 4 towards the infrared. The general profile of the spectral dimension of the recently introduced multifractional spaces is constructed for the first time.

  19. Cation diffusion in titanomagnetites

    NASA Astrophysics Data System (ADS)

    Aragon, R.; McCallister, R. H.; Harrison, H. R.

    1984-02-01

    Interdiffusion couple experiments were performed with titanomagnetite single crystals at 1,000°C, 1,100° C and 1,200° C in various buffered atmospheres. The dependence of the interdiffusion coefficient on oxygen fugacity, composition and temperature was interpreted in terms of point defect structure. Estimates of the cation tracer diffusivities indicate that Fe migrates via a point defect mechanism, involving mixed tetrahedral-octahedral site jumps, with an activation energy of 33 Kcal/mole; whereas Ti migration is one to two orders of magnitude slower, is restricted to octahedral sites and has an activation energy of 60 Kcal/mole.

  20. Accelerated stochastic diffusion processes

    NASA Astrophysics Data System (ADS)

    Garbaczewski, Piotr

    1990-07-01

    We give a purely probabilistic demonstration that all effects of non-random (external, conservative) forces on the diffusion process can be encoded in the Nelson ansatz for the second Newton law. Each random path of the process together with a probabilistic weight carries a phase accumulation (complex valued) weight. Random path summation (integration) of these weights leads to the transition probability density and transition amplitude respectively between two spatial points in a given time interval. The Bohm-Vigier, Fenyes-Nelson-Guerra and Feynman descriptions of the quantum particle behaviours are in fact equivalent.

  1. Metabolism of 2-Chloro-4-Nitroaniline via Novel Aerobic Degradation Pathway by Rhodococcus sp. Strain MB-P1

    PubMed Central

    Khan, Fazlurrahman; Pal, Deepika; Vikram, Surendra; Cameotra, Swaranjit Singh

    2013-01-01

    2-chloro-4-nitroaniline (2-C-4-NA) is used as an intermediate in the manufacture of dyes, pharmaceuticals, corrosion inhibitor and also used in the synthesis of niclosamide, a molluscicide. It is marked as a black-listed substance due to its poor biodegradability. We report biodegradation of 2-C-4-NA and its pathway characterization by Rhodococcus sp. strain MB-P1 under aerobic conditions. The strain MB-P1 utilizes 2-C-4-NA as the sole carbon, nitrogen, and energy source. In the growth medium, the degradation of 2-C-4-NA occurs with the release of nitrite ions, chloride ions, and ammonia. During the resting cell studies, the 2-C-4-NA-induced cells of strain MB-P1 transformed 2-C-4-NA stoichiometrically to 4-amino-3-chlorophenol (4-A-3-CP), which subsequently gets transformed to 6-chlorohydroxyquinol (6-CHQ) metabolite. Enzyme assays by cell-free lysates prepared from 2-C-4-NA-induced MB-P1 cells, demonstrated that the first enzyme in the 2-C-4-NA degradation pathway is a flavin-dependent monooxygenase that catalyzes the stoichiometric removal of nitro group and production of 4-A-3-CP. Oxygen uptake studies on 4-A-3-CP and related anilines by 2-C-4-NA-induced MB-P1 cells demonstrated the involvement of aniline dioxygenase in the second step of 2-C-4-NA degradation. This is the first report showing 2-C-4-NA degradation and elucidation of corresponding metabolic pathway by an aerobic bacterium. PMID:23614030

  2. Developmental changes in P1 and N1 central auditory responses elicited by consonant-vowel syllables.

    PubMed

    Sharma, A; Kraus, N; McGee, T J; Nicol, T G

    1997-11-01

    Normal maturation and functioning of the central auditory system affects the development of speech perception and oral language capabilities. This study examined maturation of central auditory pathways as reflected by age-related changes in the P1/N1 components of the auditory evoked potential (AEP). A synthesized consonant-vowel syllable (ba) was used to elicit cortical AEPs in 86 normal children ranging in age from 6 to 15 years and ten normal adults. Distinct age-related changes were observed in the morphology of the AEP waveform. The adult response consists of a prominent negativity (N1) at about 100 ms, preceded by a smaller P1 component at about 50 ms. In contrast, the child response is characterized by a large P1 response at about 100 ms. This wave decreases significantly in latency and amplitude up to about 20 years of age. In children, P1 is followed by a broad negativity at about 200 ms which we term N1b. Many subjects (especially older children) also show an earlier negativity (N1a). Both N1a and N1b latencies decrease significantly with age. Amplitudes of N1a and N1b do not show significant age-related changes. All children have the N1b; however, the frequency of occurrence of N1a increases with age. Data indicate that the child P1 develops systematically into the adult response; however, the relationship of N1a and N1b to the adult N1 is unclear. These results indicate that maturational changes in the central auditory system are complex and extend well into the second decade of life.

  3. Rapid Auditory Processing and Learning Deficits in Rats With P1 versus P7 Neonatal Hypoxic-Ischemic Injury

    PubMed Central

    McClure, Melissa M.; Threlkeld, Steven W.; Rosen, Glenn D.; Fitch, R. Holly

    2014-01-01

    Hypoxia-ischemia (HI) is associated with premature birth, and injury during term birth. Many infants experiencing HI later show disruptions of language, with research suggesting that rapid auditory processing (RAP) deficits, or impairments in the ability to discriminate rapidly changing acoustic signals, play a causal role in emergent language problems. We recently bridged these lines of research by showing RAP deficits in rats with unilateral-HI injury induced on postnatal day 1, 7, or 10 (P1, P7, or P10; 23). While robust RAP deficits were found in HI animals, it was suggested that our within-age sample size did not provide us with sufficient power to detect Age-at-injury differences within HI groups. The current study sought to examine differences in neuropathology and behavior following unilateral-HI injury in P1 vs. P7 pups. Ages chosen for HI induction reflect differential stages of neurodevelopmental maturity, and subsequent regional differences in vulnerability to reduced blood flow/oxygen (modeling premature/term HI injury). Results showed that during the juvenile period, both P1 and P7 HI groups exhibited significant RAP deficits, but the deficit in the P1 HI group resolved with repeated testing (compared to shams). However, P7 HI animals showed lasting deficits in RAP and spatial learning/memory through adulthood. The current findings are in accord with evidence that HI injury during different stages of developmental maturity (Age-at-injury) leads to differential neuropathologies, and provide the novel observation that in rats, P1 vs. P7 induced pathologies are associated with different patterns of auditory processing and learning/memory deficits across the lifespan. PMID:16765458

  4. Differential FoxP2 and FoxP1 expression in a vocal learning nucleus of the developing budgerigar.

    PubMed

    Whitney, Osceola; Voyles, Tawni; Hara, Erina; Chen, Qianqian; White, Stephanie A; Wright, Timothy F

    2015-07-01

    The forkhead domain FOXP2 and FOXP1 transcription factors are implicated in several cognitive disorders with language deficits, notably autism, and thus play a central role in learned vocal motor behavior in humans. Although a similar role for FoxP2 and FoxP1 is proposed for other vertebrate species, including songbirds, the neurodevelopmental expression of these genes are unknown in a species with lifelong vocal learning abilities. Like humans, budgerigars (Melopsittacus undulatus) learn new vocalizations throughout their entire lifetime. Like songbirds, budgerigars have distinct brain nuclei for vocal learning, which include the magnocellular nucleus of the medial striatum (MMSt), a basal ganglia region that is considered developmentally and functionally analogous to Area X in songbirds. Here, we used in situ hybridization and immunohistochemistry to investigate FoxP2 and FoxP1 expression in the MMSt of juvenile and adult budgerigars. We found FoxP2 mRNA and protein expression levels in the MMSt that were lower than the surrounding striatum throughout development and adulthood. In contrast, FoxP1 mRNA and protein had an elevated MMSt/striatum expression ratio as birds matured, regardless of their sex. These results show that life-long vocal plasticity in budgerigars is associated with persistent low-level FoxP2 expression in the budgerigar MMSt, and suggests the possibility that FoxP1 plays an organizational role in the neurodevelopment of vocal motor circuitry. Thus, developmental regulation of the FoxP2 and FoxP1 genes in the basal ganglia appears essential for vocal mimicry in a range of species that possess this relatively rare trait.

  5. Enterohemorrhagic Escherichia coli O157:H7 gal Mutants Are Sensitive to Bacteriophage P1 and Defective in Intestinal Colonization▿

    PubMed Central

    Ho, Theresa Deland; Waldor, Matthew K.

    2007-01-01

    Enterohemorrhagic Escherichia coli (EHEC), especially E. coli O157:H7, is an emerging cause of food-borne illness. Unfortunately, E. coli O157 cannot be genetically manipulated using the generalized transducing phage P1, presumably because its extensive O antigen obscures the P1 receptor, the lipopolysaccharide (LPS) core subunit. The GalE, GalT, GalK, and GalU proteins are necessary for modifying galactose before it can be assembled into the repeating subunit of the O antigen. Here, we constructed E. coli O157:H7 gal mutants which presumably have little or no O antigen. These strains were able to adsorb P1. P1 lysates grown on the gal mutant strains could be used to move chromosomal markers between EHEC strains, thereby facilitating genetic manipulation of E. coli O157:H7. The gal mutants could easily be reverted to a wild-type Gal+ strain using P1 transduction. We found that the O157:H7 galETKM::aad-7 deletion strain was 500-fold less able to colonize the infant rabbit intestine than the isogenic Gal+ parent, although it displayed no growth defect in vitro. Furthermore, in vivo a Gal+ revertant of this mutant outcompeted the galETKM deletion strain to an extent similar to that of the wild type. This suggests that the O157 O antigen is an important intestinal colonization factor. Compared to the wild type, EHEC gal mutants were 100-fold more sensitive to a peptide derived from bactericidal permeability-increasing protein, a bactericidal protein found on the surface of intestinal epithelial cells. Thus, one way in which the O157 O antigen may contribute to EHEC intestinal colonization is to promote resistance to host-derived antimicrobial polypeptides. PMID:17158899

  6. Differential FoxP2 and FoxP1 expression in a vocal learning nucleus of the developing budgerigar

    PubMed Central

    Whitney, Osceola; Voyles, Tawni; Hara, Erina; Chen, Qianqian; White, Stephanie A.; Wright, Timothy F.

    2014-01-01

    The forkhead domain FOXP2 and FOXP1 transcription factors are implicated in several cognitive disorders with language deficits, notably autism, and thus play a central role in learned vocal motor behavior in humans. Although a similar role for FoxP2 and FoxP1 is proposed for other vertebrate species, including songbirds, the neurodevelopmental expression of these genes are unknown in a species with lifelong vocal learning abilities. Like humans, budgerigars (Melopsittacus undulatus) learn new vocalizations throughout their entire lifetime. Like songbirds, budgerigars have distinct brain nuclei for vocal learning, which include the magnocellular nucleus of the medial striatum (MMSt), a basal ganglia region that is considered developmentally and functionally analogous to Area X in songbirds. Here we used in situ hybridization and immunohistochemistry to investigate FoxP2 and FoxP1 expression in the MMSt of juvenile and adult budgerigars. We found FoxP2 mRNA and protein expression levels in the MMSt that were lower than the surrounding striatum throughout development and adulthood. In contrast, FoxP1 mRNA and protein had an elevated MMSt/striatum expression ratio as birds matured, regardless of their sex. These results show that life-long vocal plasticity in budgerigars is associated with persistent low-level FoxP2 expression in the budgerigar MMSt, and suggests the possibility that FoxP1 plays an organizational role in the neurodevelopment of vocal motor circuitry. Thus, developmental regulation of the FoxP2 and FoxP1 genes in the basal ganglia appears essential for vocal mimicry in a range of species that possess this relatively rare trait. PMID:25407828

  7. Broad-Host-Range Plasmids from Agricultural Soils Have IncP-1 Backbones with Diverse Accessory Genes▿

    PubMed Central

    Sen, Diya; Van der Auwera, Geraldine A.; Rogers, Linda M.; Thomas, Christopher M.; Brown, Celeste J.; Top, Eva M.

    2011-01-01

    Broad-host-range plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to antibiotics and heavy metals or degradation of pollutants. Although some broad-host-range plasmids have been extensively studied, their evolutionary history and genetic diversity remain largely unknown. The goal of this study was to analyze and compare the genomes of 12 broad-host-range plasmids that were previously isolated from Norwegian soils by exogenous plasmid isolation and that encode mercury resistance. Complete nucleotide sequencing followed by phylogenetic analyses based on the relaxase gene traI showed that all the plasmids belong to one of two subgroups (β and ε) of the well-studied incompatibility group IncP-1. A diverse array of accessory genes was found to be involved in resistance to antimicrobials (streptomycin, spectinomycin, and sulfonamides), degradation of herbicides (2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenoxypropionic acid), and a putative new catabolic pathway. Intramolecular transposition of insertion sequences followed by deletion was found to contribute to the diversity of some of these plasmids. The previous observation that the insertion sites of a Tn501-related element are identical in four IncP-1β plasmids (pJP4, pB10, R906, and R772) was further extended to three more IncP-1β plasmids (pAKD15, pAKD18, and pAKD29). We proposed a hypothesis for the evolution of these Tn501-bearing IncP-1β plasmids that predicts recent diversification followed by worldwide spread. Our study increases the available collection of complete IncP-1 plasmid genome sequences by 50% and will aid future studies to enhance our understanding of the evolution and function of this important plasmid family. PMID:21948829

  8. Toxoid construction of AsaP1, a lethal toxic aspzincin metalloendopeptidase of Aeromonas salmonicida subsp. achromogenes, and studies of its activity and processing.

    PubMed

    Schwenteit, Johanna; Bogdanović, Xenia; Fridjonsson, Olafur H; Aevarsson, Arnthor; Bornscheuer, Uwe T; Hinrichs, Winfried; Gudmundsdottir, Bjarnheidur K

    2013-03-23

    AsaP1 is a toxic aspzincin metalloendopeptidase secreted by the fish pathogen Aeromonas salmonicida subsp. achromogenes. The protease is highly immunogenic and antibodies against AsaP1 evoke a passive protection against infection with A. salmonicida subsp. achromogenes. The protease is expressed as 37 kDa pre-pro-protein and processed to an active enzyme of 19kDa in A. salmonicida subsp. achromogenes. Recombinant expression of AsaP1(rec) in E. coli results in a protease of 22 kDa that is not secreted. AsaP1(rec) induces comparable pathological changes in Atlantic salmon (Salmo salar L.) to native AsaP1(wt). The aim of the study was to construct AsaP1 toxoids by exchanging catalytically important amino acids in the active site region of the protease. Four different AsaP1 mutants (AsaP1(E294A), AsaP1(E294Q), AsaP1(Y309A), and AsaP1(Y309F)) were successfully constructed by one step site directed mutagenesis, expressed in E. coli BL21 C43 as pre-pro-proteins and purified by His-tag affinity chromatography and gel filtration. Three of the resulting mutants (AsaP1(E294A), AsaP1(E294Q), and AsaP1(Y309A)) were not caseinolytic active and are detected as unprocessed pre-pro-proteins of 37 kDa. Caseinolytic active AsaP1(rec) and a mutant with reduced activity, AsaP1(Y309F), were processed to a size of 22 kDa. Furthermore, AsaP1(rec) is able to process the inactive mutants to the mature size of 22 kDa, allowing the conclusion that AsaP1 is autocatalytically processed. All four mutants AsaP1(E294A), AsaP1(E294Q), AsaP1(Y309A) and AsaP1(Y309F) are non-toxic in fish but induce a specific anti-AsaP1 antibody response in Arctic charr (Salvelinus alpinus L.) and are therefore true toxoids and possible vaccine additives. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. A simple flow analysis of diffuser-getter-diffuser systems

    SciTech Connect

    Klein, J. E.; Howard, D. W.

    2008-07-15

    Tritium clean-up systems typically deploy gas processing technologies between stages of palladium-silver (Pd/Ag) diffusers/permeators. The number of diffusers positioned before and after a gas clean-up process to obtain optimal system performance will vary with feed gas inert composition. A simple method to analyze optimal diffuser configuration is presented. The method assumes equilibrium across the Pd/Ag tubes and system flows are limited by diffuser vacuum pump speeds preceding or following the clean-up process. A plot of system feed as a function of inert feed gas composition for various diffuser configuration allows selection of a diffuser configuration for maximum throughput based on feed gas composition. (authors)

  10. FLOW ANALYSIS OF DIFFUSER-GETTER-DIFFUSER SYSTEMS

    SciTech Connect

    Klein, J; Dave W. Howard, D

    2007-07-24

    Tritium clean-up systems typically deploy gas processing technologies between stages of palladium-silver (Pd/Ag) diffusers/permeators. The number of diffusers positioned before and after a gas clean-up process to obtain optimal system performance will vary with feed gas inert composition. A simple method to analyze optimal diffuser configuration is presented. The method assumes equilibrium across the Pd/Ag tubes and system flows are limited by diffuser vacuum pump speeds preceding or following the clean-up process. A plot of system feed as a function of inert feed gas composition for various diffuser configuration allows selection of a diffuser configuration for maximum throughput based on feed gas composition.

  11. Apparatus for diffusion separation

    DOEpatents

    Nierenberg, William A.

    1976-08-10

    1. A diffuser separator apparatus which comprises a plurality of flow channels in a single stage, each of said channels having an inlet port and an outlet port and a constant cross sectional area between said ports, at least a portion of the defining surface of each of said channels being a diffusion separation membrane, and each of said channels having a different cross sectional area, means for connecting said channels in series so that each successive channel of said series has a smaller cross sectional area than the previous channel of said series, a source of gaseous mixture, individual means for flowing said gaseous mixture to the inlet port of each of said channels, gas receiving and analyzing means, individual means for flowing gas passing from each of said outlet ports and means for flowing gas passing through said membranes to said receiving and analyzing means, and individual means for connecting the outlet port of each channel with the inlet port of the channel having the next smaller cross sectional area.

  12. Sampling diffusive transition paths

    SciTech Connect

    F. Miller III, Thomas; Predescu, Cristian

    2006-10-12

    We address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with sampling infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with sampling the coarse features of long paths. The fine-features sampling stiffness is eliminated with the use of the fast sampling algorithm (FSA), and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. We use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature.

  13. Cosmic Diffuse Analysis

    NASA Technical Reports Server (NTRS)

    Ryan, James M.

    1999-01-01

    The final analysis of the COMPTEL cosmic diffuse flux analysis is summarized in the accompanying figure. It shows the intensity of the cosmic diffuse flux spectrum measured jointly between the Virgo region and the South Galactic pole. This spectrum represents flux per unit solid angle over the range of 0.8 to 30 MeV. It contains the first positive measurement of the flux above 10 MeV. The spectrum merges smoothly with that measured with the EGRET instrument, starting at 30 MeV. It also merges smoothly with the latest results of the HEAO-1 measurements. However, the spectrum below is softer than the spectrum above the COMPTEL energy band. In the COMPTEL energy band there must exist a change in spectral shape as the source objects or processes change from the lower energy regime to the higher energy regime. The details of the analysis and the implications and meanings of the results are spelled out in the thesis of Dr. Cheenu Kappadath which is enclosed.

  14. Diffuse Alveolar Hemorrhage

    PubMed Central

    2013-01-01

    Diffuse alveolar hemorrhage (DAH) is a life-threatening and medical emergency that can be caused by numerous disorders and presents with hemoptysis, anemia, and diffuse alveolar infiltrates. Early bronchoscopy with bronchoalveolar lavage is usually required to confirm the diagnosis and rule out infection. Most cases of DAH are caused by capillaritis associated with systemic autoimmune diseases such as anti-neutrophil cytoplasmic antibody-associated vasculitis, anti-glomerular basement membrane disease, and systemic lupus erythematosus, but DAH may also result from coagulation disorders, drugs, inhaled toxins, or transplantation. The diagnosis of DAH relies on clinical suspicion combined with laboratory, radiologic, and pathologic findings. Early recognition is crucial, because prompt diagnosis and treatment is necessary for survival. Corticosteroids and immunosuppressive agents remain the gold standard. In patients with DAH, biopsy of involved sites can help to identify the cause and to direct therapy. This article aims to provide a general review of the causes and clinical presentation of DAH and to recommend a diagnostic approach and a management plan for the most common causes. PMID:23678356

  15. Cosmic Diffuse Analysis

    NASA Technical Reports Server (NTRS)

    Ryan, James M.

    1999-01-01

    The final analysis of the COMPTEL cosmic diffuse flux analysis is summarized in the accompanying figure. It shows the intensity of the cosmic diffuse flux spectrum measured jointly between the Virgo region and the South Galactic pole. This spectrum represents flux per unit solid angle over the range of 0.8 to 30 MeV. It contains the first positive measurement of the flux above 10 MeV. The spectrum merges smoothly with that measured with the EGRET instrument, starting at 30 MeV. It also merges smoothly with the latest results of the HEAO-1 measurements. However, the spectrum below is softer than the spectrum above the COMPTEL energy band. In the COMPTEL energy band there must exist a change in spectral shape as the source objects or processes change from the lower energy regime to the higher energy regime. The details of the analysis and the implications and meanings of the results are spelled out in the thesis of Dr. Cheenu Kappadath which is enclosed.

  16. The diffusion of microfinance.

    PubMed

    Banerjee, Abhijit; Chandrasekhar, Arun G; Duflo, Esther; Jackson, Matthew O

    2013-07-26

    To study the impact of the choice of injection points in the diffusion of a new product in a society, we developed a model of word-of-mouth diffusion and then applied it to data on social networks and participation in a newly available microfinance loan program in 43 Indian villages. Our model allows us to distinguish information passing among neighbors from direct influence of neighbors' participation decisions, as well as information passing by participants versus nonparticipants. The model estimates suggest that participants are seven times as likely to pass information compared to informed nonparticipants, but information passed by nonparticipants still accounts for roughly one-third of eventual participation. An informed household is not more likely to participate if its informed friends participate. We then propose two new measures of how effective a given household would be as an injection point. We show that the centrality of the injection points according to these measures constitutes a strong and significant predictor of eventual village-level participation.

  17. Diffusing obesity myths.

    PubMed

    Ramos Salas, X; Forhan, M; Sharma, A M

    2014-06-01

    Misinformation or myths about obesity can lead to weight bias and obesity stigma. Counteracting myths with facts and evidence has been shown to be effective educational tools to increase an individuals' knowledge about a certain condition and to reduce stigma.The purpose of this study was to identify common obesity myths within the healthcare and public domains and to develop evidence-based counterarguments to diffuse them. An online search of grey literature, media and public health information sources was conducted to identify common obesity myths. A list of 10 obesity myths was developed and reviewed by obesity experts and key opinion leaders. Counterarguments were developed using current research evidence and validated by obesity experts. A survey of obesity experts and health professionals was conducted to determine the usability and potential effectiveness of the myth-fact messages to reduce weight bias. A total of 754 individuals responded to the request to complete the survey. Of those who responded, 464 (61.5%) completed the survey. All 10 obesity myths were identified to be deeply pervasive within Canadian healthcare and public domains. Although the myth-fact messages were endorsed, respondents also indicated that they would likely not be sufficient to reduce weight bias. Diffusing deeply pervasive obesity myths will require multilevel approaches.

  18. Diffuse Optical Tomography

    NASA Astrophysics Data System (ADS)

    Yodh, Arjun

    2000-03-01

    Application of diffuse near-infrared (NIR) optical methods for imaging and spectroscopy of tissues is attractive for several reasons. The techniques utilize non-ionizing radiation, are non-invasive, and are often technologically simple and fast. The optical method also has several unique measurable parameters with potential to enhance tumor sensitivity and specificity. For example, blood dynamics, blood volume, blood oxygen saturation, and water content are often substantially different in the rapidly growing tumor, and will alter tissue optical absorption coefficients. An increase in organelle population, particularly mitochondria, accompanies the higher metabolic activity of the rapidly growing tumor, and leads to an increasing scattering coefficient for the tumor. Similarly the optical absorption, fluorescence, and scattering of contrast agents such as Indocyanine green (ICG) that occupy vascular and extravascular space provide useful forms of sensitization. In this paper I will discuss our work exploring the tumor contrasts accessible to the diffuse optical method, and I will describe how we extract this optical information using state-of-the-art theoretical, computational, and experimental technologies.

  19. Sucrose diffusion in aqueous solution

    PubMed Central

    Murray, Benjamin J.

    2016-01-01

    The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes–Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle. PMID:27364512

  20. Kir2.1 and K2P1 channels reconstitute two levels of resting membrane potential in cardiomyocytes.

    PubMed

    Zuo, Dongchuan; Chen, Kuihao; Zhou, Min; Liu, Zheng; Chen, Haijun

    2017-08-01

    Outward and inward background currents across the cell membrane balance, determining resting membrane potential. Inward rectifier K(+) channel subfamily 2 (Kir2) channels primarily maintain the resting membrane potential of cardiomyocytes. Human cardiomyocytes exhibit two levels of resting membrane potential at subphysiological extracellular K(+) concentrations or pathological hypokalaemia, however, the underlying mechanism is unclear. In the present study, we show that human cardiomyocytes derived from induced pluripotent stem cells with enhanced expression of isoform 1 of Kir2 (Kir2.1) channels and mouse HL-1 cardiomyocytes with ectopic expression of two pore-domain K(+) channel isoform 1 (K2P1) recapitulate two levels of resting membrane potential, indicating the contributions of Kir2.1 and K2P1 channels to the phenomenon. In Chinese hamster ovary cells that express the channels, Kir2.1 currents non-linearly counterbalance hypokalaemia-induced K2P1 leak cation currents, reconstituting two levels of resting membrane potential. These findings support the hypothesis that Kir2 currents non-linearly counterbalance inward background cation currents, such as K2P1 currents, accounting for two levels of resting membrane potential in human cardiomyocytes and demonstrating a novel mechanism that regulates excitability. Inward rectifier K(+) channel subfamily 2 (Kir2) channels primarily maintain the normal resting membrane potential of cardiomyocytes. At subphysiological extracellular K(+) concentrations or pathological hypokalaemia, human cardiomyocytes show both hyperpolarized and depolarized resting membrane potentials; these depolarized potentials cause cardiac arrhythmia; however, the underlying mechanism is unknown. In the present study, we show that inward rectifier K(+) channel subfamily 2 isoform 1 (Kir2.1) currents non-linearly counterbalance hypokalaemia-induced two pore-domain K(+) channel isoform 1 (K2P1) leak cation currents, reconstituting two levels of

  1. Immunogenicity and Safety of Three Doses of a Bivalent (B:4:P1.19,15 and B:4:P1.7-2,4) Meningococcal Outer Membrane Vesicle Vaccine in Healthy Adolescents▿

    PubMed Central

    Boutriau, Dominique; Poolman, Jan; Borrow, Ray; Findlow, Jamie; Domingo, Javier Diez; Puig-Barbera, Joan; Baldó, José María; Planelles, Victoria; Jubert, Angels; Colomer, Julia; Gil, Angel; Levie, Karin; Kervyn, Anne-Diane; Weynants, Vincent; Dominguez, Francisco; Barberá, Ramon; Sotolongo, Franklin

    2007-01-01

    An experimental bivalent meningococcal outer membrane vesicle (OMV) vaccine (B:4:P1.19,15 and B:4:P1.7-2,4) has been developed to provide wide vaccine coverage particularly of the circulating strains in Europe. A randomized, controlled phase II study (study identification number, 710158/002; ClinicalTrials.gov identifier number, NCT00137917) to evaluate the immunogenicity and safety of three doses of the OMV vaccine when given to healthy 12- to 18-year-olds on a 0-2-4 month (n = 162) or 0-1-6 month schedule (n = 159). A control group received two doses of hepatitis A and one of conjugated meningococcal serogroup C vaccine on a 0-1-6 month schedule (n = 157). Immune response, defined as a fourfold increase in serum bactericidal titer using a range of vaccine-homologous or PorA-related and heterologous strains, was determined for samples taken before and 1 month after vaccination; assays were performed at two laboratories. As measured at the GlaxoSmithKline (GSK) laboratory, the OMV vaccine induced an immune response against homologous or PorA-related strains (in at least 51% of subjects against strains of serosubtype P1.19,15 and at least 66% against strains of serosubtype P1.7-2,4) and against a set of three heterologous strains (in 28% to 46% of subjects). Both laboratories showed consistent results for immune response rates. The OMV vaccine had a similar reactogenicity profile for each schedule. Pain preventing normal activities occurred in approximately one-fifth of the subjects; this was significantly higher than in the control group. The immune responses induced by the bivalent OMV vaccine demonstrated the induction of bactericidal antibodies against the vaccine-homologous/PorA-related strains but also against heterologous strains, indicating the presence of protective antigens in OMVs and confirming the potential of clinical cross-protection. PMID:17065257

  2. Diffusion limited aggregation. The role of surface diffusion

    NASA Astrophysics Data System (ADS)

    García-Ruiz, Juan M.; Otálora, Fermín

    1991-11-01

    We present a growth model in which the hitting particles are able to diffuse to more stable growth sites in the perimeter of a cluster growing by diffusion limited aggregation. By tuning the diffusion path Ls, the morphological output - from disordered fractal to perfect single crystals - can be controlled. Instabilities appear when the mean length of the crystal faces Lf are greater than 2 Ls.

  3. A rarely seen diffuse parenchymal lung disease: diffuse pulmonary meningotheliomatosis.

    PubMed

    Şen, Nazan; Canpolat, Emine Tuba; Koç, Zafer

    2015-01-01

    Pulmonary meningothelial-like nodules (MLNs) are usually detected incidentally during pathologic evaluation of resected pulmonary parenchymal specimens and autopsies. These nodules are generally asymptomatic and most often single. Diffuse pulmonary involvement by MLNs is less frequently described. MLNs are benign lesions and have been associated with neoplastic and non-neoplastic pulmonary conditions and occasionally with extrapulmonary diseases. We report a case of a female patient presenting with multiple and bilateral pulmonary nodules diagnosed with "diffuse pulmonary meningotheliomatosis" by video-assisted thoracoscopic surgery (VATS). Diffuse pulmonary meningotheliomatosis should be included in the differential diagnosis of diffuse bilateral lung nodules in the radiologic studies.

  4. Characterizing non-Gaussian diffusion by using generalized diffusion tensors.

    PubMed

    Liu, Chunlei; Bammer, Roland; Acar, Burak; Moseley, Michael E

    2004-05-01

    Diffusion tensor imaging (DTI) is known to have a limited capability of resolving multiple fiber orientations within one voxel. This is mainly because the probability density function (PDF) for random spin displacement is non-Gaussian in the confining environment of biological tissues and, thus, the modeling of self-diffusion by a second-order tensor breaks down. The statistical property of a non-Gaussian diffusion process is characterized via the higher-order tensor (HOT) coefficients by reconstructing the PDF of the random spin displacement. Those HOT coefficients can be determined by combining a series of complex diffusion-weighted measurements. The signal equation for an MR diffusion experiment was investigated theoretically by generalizing Fick's law to a higher-order partial differential equation (PDE) obtained via Kramers-Moyal expansion. A relationship has been derived between the HOT coefficients of the PDE and the higher-order cumulants of the random spin displacement. Monte-Carlo simulations of diffusion in a restricted environment with different geometrical shapes were performed, and the strengths and weaknesses of both HOT and established diffusion analysis techniques were investigated. The generalized diffusion tensor formalism is capable of accurately resolving the underlying spin displacement for complex geometrical structures, of which neither conventional DTI nor diffusion-weighted imaging at high angular resolution (HARD) is capable. The HOT method helps illuminate some of the restrictions that are characteristic of these other methods. Furthermore, a direct relationship between HOT and q-space is also established.

  5. Apparent diffusion profile estimation from high angular resolution diffusion images

    NASA Astrophysics Data System (ADS)

    Descoteaux, Maxime; Angelino, Elaine; Fitzgibbons, Shaun; Deriche, Rachid

    2006-03-01

    High angular resolution diffusion imaging (HARDI) has recently been of great interest to characterize non-Gaussian diffusion process. In the white matter of the brain, this occurs when fiber bundles cross, kiss or diverge within the same voxel. One of the important goal is to better describe the apparent diffusion process in these multiple fiber regions, thus overcoming the limitations of classical diffusion tensor imaging (DTI). In this paper, we design the appropriate mathematical tools to describe noisy HARDI data. Using a meaningful modified spherical harmonics basis to capture the physical constraints of the problem, we propose a new regularization algorithm to estimate a smoother and closer diffusivity profile to the true diffusivities without noise. We exploit properties of the spherical harmonics to define a smoothing term based on the Laplace-Beltrami for functions defined on the unit sphere. An additional contribution of the paper is the derivation of the general transformation taking the spherical harmonics coefficients to the high order tensor independent elements. This allows the careful study of the state of the art high order anisotropy measures computed from either spherical harmonics or tensor coefficients. We analyze their ability to characterize the underlying diffusion process. We are able to recover voxels with isotropic, single fiber anisotropic and multiple fiber anisotropic diffusion. We test and validate the approach on diffusion profiles from synthetic data and from a biological rat phantom.

  6. Complementation of a poliovirus defective genome by a recombinant vaccinia virus which provides poliovirus P1 capsid precursor in trans.

    PubMed Central

    Ansardi, D C; Porter, D C; Morrow, C D

    1993-01-01

    Defective interfering (DI) RNA genomes of poliovirus which contain in-frame deletions in the P1 capsid protein-encoding region have been described. DI genomes are capable of replication and can be encapsidated by capsid proteins provided in trans from wild-type poliovirus. In this report, we demonstrate that a previously described poliovirus DI genome (K. Hagino-Yamagishi and A. Nomoto, J. Virol. 63:5386-5392, 1989) can be complemented by a recombinant vaccinia virus, VVP1 (D. C. Ansardi, D. C. Porter, and C. D. Morrow, J. Virol. 65:2088-2092, 1991), which expresses the poliovirus capsid precursor polyprotein, P1. Stocks of defective polioviruses were generated by transfecting in vitro-transcribed defective genome RNA derived from plasmid pSM1(T7)1 into HeLa cells infected with VVP1 and were maintained by serial passage in the presence of VVP1. Encapsidation of the defective poliovirus genome was demonstrated by characterizing poliovirus-specific protein expression in cells infected with preparations of defective poliovirus and by Northern (RNA) blot analysis of poliovirus-specific RNA incorporated into defective poliovirus particles. Cells infected with preparations of defective poliovirus expressed poliovirus protein 3CD but did not express capsid proteins derived from a full-length P1 precursor. Poliovirus-specific RNA encapsidated in viral particles generated in cells coinfected with VVP1 and defective poliovirus migrated slightly faster on formaldehyde-agarose gels than wild-type poliovirus RNA, demonstrating maintenance of the genomic deletion. By metabolic radiolabeling with [35S]methionine-cysteine, the defective poliovirus particles were shown to contain appropriate mature-virion proteins. This is the first report of the generation of a pure population of defective polioviruses free of contaminating wild-type poliovirus. We demonstrate the use of this recombinant vaccinia virus-defective poliovirus genome complementation system for studying the effects of

  7. The activation of P1- and P2-purinoceptors in the guinea-pig left atrium by diadenosine polyphosphates.

    PubMed Central

    Hoyle, C. H.; Ziganshin, A. U.; Pintor, J.; Burnstock, G.

    1996-01-01

    1. The effects of P1, P2-di(adenosine) pyrophosphate (AP2A), P1, P3-di(adenosine) triphosphate (AP3A), P1,P4-di(adenosine) tetraphosphate (AP4A), P1,P5-di(adenosine) pentaphosphate (AP5A), ATP, alpha, beta-methylene ADP and 2-chloroadenosine (2-ClAd) were examined in the guinea-pig driven left atrium. 2. All these purine compounds except alpha, beta-methylene ADP produced a negative inotropic response with a rank order of potency of: 2-ClAd > > AP2A > or = ATP > or = AP4A = AP3A = AP5A. The EC50 value for 2-ClAd was approximately 1 microM, while those for the remaining compounds were in the range 10 microM-100 microM, alpha, beta-Methylene ADP (10-300 microM), a selective P2Y-purinoceptor agonist, produced a small positive inotropism. 3. The P1-purinoceptor antagonist, 8-para-sulphophenyltheophylline (8-pSPT, 20 microM) caused a right-ward shift in the concentration-response curves for 2-ClAd, ATP and AP2A, but converted the responses of AP3A, AP4A, and AP5A into positive inotropisms. 4. The non-selective P2-purinoceptor antagonist, suramin (300 microM), had no significant effect on the concentration-response curves for 2-ClAd, ATP or AP2A, but significantly antagonized inhibitory responses to AP3A, AP4A and AP5A, and excitatory responses to alpha, beta-methylene ADP. 5. In the presence of 8-pSPT (20 microM), suramin (300 microM) abolished the positive inotropic responses evoked by the dinucleotides. 6. ATP was degraded far more rapidly than any of the dinucleotides, and AP3A was the least stable of the diadenosine compounds. The relative order of stability was AP2A > AP4A = AP5A > AP3A > > ATP. Suramin (300 microM) reduced the rate of degradation of ATP and AP3A by approximately 30%. Suramin had no significant effect on the degradation of AP2A, AP4A or AP5A. 7. It is concluded that the diadenosine polyphosphates cause negative inotropic responses via P1-purinoceptors and a hitherto undefined suramin-sensitive P2-purinoceptor, and that they appear to have positive

  8. Intracellular Signaling and Desmoglein 2 Shedding Triggered by Human Adenoviruses Ad3, Ad14, and Ad14P1

    PubMed Central

    Wang, Hongjie; Ducournau, Corinne; Saydaminova, Kamola; Richter, Maximilian; Yumul, Roma; Ho, Martin; Carter, Darrick; Zubieta, Chloé

    2015-01-01

    ABSTRACT We recently discovered that desmoglein 2 (DSG2) is a receptor for human adenovirus species B serotypes Ad3, Ad7, Ad11, and Ad14. Ad3 is considered to be a widely distributed human pathogen. Ad3 binding to DSG2 triggers the transient opening of epithelial junctions. Here, we further delineate the mechanism that leads to DSG2-mediated epithelial junction opening in cells exposed to Ad3 and recombinant Ad3 fiber proteins. We identified an Ad3 fiber knob-dependent pathway that involves the phosphorylation of mitogen-activated protein (MAP) kinases triggering the activation of the matrix-metalloproteinase ADAM17. ADAM17, in turn, cleaves the extracellular domain of DSG2 that links epithelial cells together. The shed DSG2 domain can be detected in cell culture supernatant and also in serum of mice with established human xenograft tumors. We then extended our studies to Ad14 and Ad14P1. Ad14 is an important research and clinical object because of the recent appearance of a new, more pathogenic strain (Ad14P1). In a human epithelial cancer xenograft model, Ad14P1 showed more efficient viral spread and oncolysis than Ad14. Here, we tested the hypothesis that a mutation in the Ad14P1 fiber knob could account for the differences between the two strains. While our X-ray crystallography studies suggested an altered three-dimensional (3D) structure of the Ad14P1 fiber knob in the F-G loop region, this did not significantly change the fiber knob affinity to DSG2 or the intracellular signaling and DSG2 shedding in epithelial cancer cells. IMPORTANCE A number of widely distributed adenoviruses use the epithelial junction protein DSG2 as a receptor for infection and lateral spread. Interaction with DSG2 allows the virus not only to enter cells but also to open epithelial junctions which form a physical barrier to virus spread. Our study elucidates the mechanism beyond virus-triggered junction opening with a focus on adenovirus serotype 3. Ad3 binds to DSG2 with its fiber

  9. Coupling p-multigrid to geometric multigrid for discontinuous Galerkin formulations of the convection-diffusion equation

    NASA Astrophysics Data System (ADS)

    Mascarenhas, Brendan S.; Helenbrook, Brian T.; Atkins, Harold L.

    2010-05-01

    An improved p-multigrid algorithm for discontinuous Galerkin (DG) discretizations of convection-diffusion problems is presented. The general p-multigrid algorithm for DG discretizations involves a restriction from the p=1 to p=0 discontinuous polynomial solution spaces. This restriction is problematic and has limited the efficiency of the p-multigrid method. For purely diffusive problems, Helenbrook and Atkins have demonstrated rapid convergence using a method that restricts from a discontinuous to continuous polynomial solution space at p=1. It is shown that this method is not directly applicable to the convection-diffusion (CD) equation because it results in a central-difference discretization for the convective term. To remedy this, ideas from the streamwise upwind Petrov-Galerkin (SUPG) formulation are used to devise a transition from the discontinuous to continuous space at p=1 that yields an upwind discretization. The results show that the new method converges rapidly for all Peclet numbers.

  10. Apoplastic Diffusion Barriers in Arabidopsis

    PubMed Central

    Schreiber, Lukas; Franke, Rochus Benni; Geldner, Niko; Reina-Pinto, José J.; Kunst, Ljerka

    2013-01-01

    During the development of Arabidopsis and other land plants, diffusion barriers are formed in the apoplast of specialized tissues within a variety of plant organs. While the cuticle of the epidermis is the primary diffusion barrier in the shoot, the Casparian strips and suberin lamellae of the endodermis and the periderm represent the diffusion barriers in the root. Different classes of molecules contribute to the formation of extracellular diffusion barriers in an organ- and tissue-specific manner. Cutin and wax are the major components of the cuticle, lignin forms the early Casparian strip, and suberin is deposited in the stage II endodermis and the periderm. The current status of our understanding of the relationships between the chemical structure, ultrastructure and physiological functions of plant diffusion barriers is discussed. Specific aspects of the synthesis of diffusion barrier components and protocols that can be used for the assessment of barrier function and important barrier properties are also presented. PMID:24465172

  11. Osmosis and diffusion conceptual assessment.

    PubMed

    Fisher, Kathleen M; Williams, Kathy S; Lineback, Jennifer Evarts

    2011-01-01

    Biology student mastery regarding the mechanisms of diffusion and osmosis is difficult to achieve. To monitor comprehension of these processes among students at a large public university, we developed and validated an 18-item Osmosis and Diffusion Conceptual Assessment (ODCA). This assessment includes two-tiered items, some adopted or modified from the previously published Diffusion and Osmosis Diagnostic Test (DODT) and some newly developed items. The ODCA, a validated instrument containing fewer items than the DODT and emphasizing different content areas within the realm of osmosis and diffusion, better aligns with our curriculum. Creation of the ODCA involved removal of six DODT item pairs, modification of another six DODT item pairs, and development of three new item pairs addressing basic osmosis and diffusion concepts. Responses to ODCA items testing the same concepts as the DODT were remarkably similar to responses to the DODT collected from students 15 yr earlier, suggesting that student mastery regarding the mechanisms of diffusion and osmosis remains elusive.

  12. Facilitated diffusion on confined DNA.

    PubMed

    Foffano, G; Marenduzzo, D; Orlandini, E

    2012-02-01

    In living cells, proteins combine three-dimensional bulk diffusion and one-dimensional sliding along the DNA to reach a target faster. This process is known as facilitated diffusion and we investigate its dynamics in the physiologically relevant case of confined DNA. The confining geometry and DNA elasticity are key parameters: We find that facilitated diffusion is most efficient inside an isotropic volume and on a flexible polymer. By considering the typical copy numbers of proteins in vivo, we show that the speedup due to sliding becomes insensitive to fine tuning of parameters, rendering facilitated diffusion a robust mechanism to speed up intracellular diffusion-limited reactions. The parameter range we focus on is relevant for in vitro systems and for facilitated diffusion on yeast chromatin. © 2012 American Physical Society

  13. Is anomalous transport diffusive

    SciTech Connect

    Rewoldt, G.

    1989-09-01

    It has often been assumed that the anomalous transport from saturated plasma instabilities is diffusive'' in the sense that the particle flux, {Gamma}, the electron energy flux, q{sub e}, and the ion energy flux, q{sub i}, can be written in forms that are linear in the density gradient, dn/dr, the electron temperature gradient, dT{sub e}/dr, and the ion temperature gradient dT{sub i}/dr. In the simplest form, {Gamma} = {minus} D{sub n}{sup n}(dn/dr), q{sub e} = {minus} D{sub e}{sup e}n(dT{sub e}/dr), and q{sub i} = {minus}D{sub i}{sup i}n(dT{sub i}/dr). A possible generalization of this is to include so-called off-diagonal'' terms, with {Gamma} = nV{sub n} {minus} D{sub n}{sup n}(dn/dr) {minus} D{sub n}{sup e}(n/T{sub e})(dT{sub e}/dr) {minus} D{sub n}{sup i}(n/T{sub i})(dT{sub i}/dr), with corresponding forms for the energy fluxes. Here, general results for the quasilinear particle and energy fluxes, resulting from tokamak linear microinstabilities, are evaluated to assess the relative importance of the diagonal and the off-diagonal terms. A further possible generatlization is to include also contributions to the fluxes from higher powers of the gradients, specifically quadratic'' contributions proportional to (dn/dr){sup 2}, (dn/dr)(dT{sub e}/dr), and so on. A procedure is described for evaluating the corresponding coefficients, and results are presented for illustrative realistic tokamak cases. Qualitatively, it is found that the off-diagonal diffusion coefficients can be as big as the diagonal ones, and that the quadratic terms can be larger than the linear ones. The results thus strongly suggest that the commonly used diffusive'' approximation with only diagonal terms, {Gamma} = {minus}D{sub n}{sup n}(dn/dr), and correspondingly for the energy fluxes, is not adequate in practice. 9 refs., 1 tabs.

  14. Bacteriophage P1 pac sites inserted into the chromosome greatly increase packaging and transduction of Escherichia coli genomic DNA.

    PubMed

    Huang, Haomin; Masters, Millicent

    2014-11-01

    The Escherichia coli bacteriophage P1 packages host chromosome separately from phage DNA, and transfers it to recipient cells at low frequency in a process called generalized transduction. Phage genomes are packaged from concatemers beginning at a specific site, pac. To increase transduction rate, we have inserted pac into the chromosome at up to five equally spaced positions; at least this many are fully tolerated in the absence of P1 infection. A single chromosomal pac greatly increases transduction of downstream markers without decreasing phage yields; 3.5 × as much total chromosomal DNA is packaged. Additional insertions decrease phage yield by > 90% and also decrease phage DNA synthesis, although less dramatically. Packaging of chromosomal markers near to and downstream of each inserted pac site is, at the same time, increased by greater than 10 fold. Transduction of markers near an inserted pac site can be increased by over 1000-fold, potentially allowing identification of such transductants by screening.

  15. Origin pairing (‘handcuffing’) as a mode of negative control of P1 plasmid copy number

    PubMed Central

    Park, Kyusung; Han, Ernest; Paulsson, Johan; Chattoraj, Dhruba K.

    2001-01-01

    In one family of bacterial plasmids, multiple initiator binding sites, called iterons, are used for initiation of plasmid replication as well as for the control of plasmid copy number. Iterons can also pair in vitro via the bound initiators. This pairing, called handcuffing, has been suggested to cause steric hindrance to initiation and thereby control the copy number. To test this hypothesis, we have compared copy numbers of isogenic miniP1 plasmid monomer and dimer. The dimer copy number was only one-quarter that of the monomer, suggesting that the higher local concentration of origins in the dimer facilitated their pairing. Physical evidence consistent with iteron-mediated pairing of origins preferentially in the dimer was obtained in vivo. Thus, origin handcuffing can be a mechanism to control P1 plasmid replication. PMID:11743008

  16. Suppression of the lexC (ssbA) mutation of Escherichia coli by a mutant of bacteriophage P1.

    PubMed

    Johnson, B F

    1982-01-01

    A new mutant of bacteriophage P1 designated lxc that suppresses the phenotype of lexC and ssbA mutants of Escherichia coli was isolated and characterized. The properties of lexC mutants suppressed by the lxc mutation include temperature sensitive growth at 42 degrees C, sensitivity to ultraviolet light and alkylating agents, and a nonmutagenic response following exposure to ultraviolet irradiation. A bac mutant of bacteriophage P1 that suppresses the temperature sensitivity of dnaB mutants does not affect the phenotype of lexC or ssbA mutants. Neither the lxc or bac mutations affect the ultraviolet light sensitivity of strains with the mutations uvrA155, lexA102, or recA56.

  17. A comprehensive study of the vibrationally resolved S 2p(-1) Auger electron spectrum of carbonyl sulfide.

    PubMed

    Sekushin, V; Püttner, R; Fink, R F; Martins, M; Jiang, Y H; Aksela, H; Aksela, S; Kaindl, G

    2012-07-28

    High-resolution normal Auger-electron spectra of carbonyl sulfide subsequent to S 2p(-1) photoionization at photon energies of 200, 220, and 240 eV are reported along with corresponding photoelectron spectra. In addition, theoretical results are presented that take the core-hole orientation of the various spin-orbit-split and molecular-field-split S 2p(-1) states into account. Auger transitions to eight metastable dicationic final states are observed and assigned on the basis of the theoretical results. From Franck-Condon analysis, assuming Morse potentials along the normal coordinates for seven of the observed quasi-stable dicationic final states, information on the potential-energy surfaces is derived and compared with theoretical results from the literature.

  18. Structure elucidation of DNA interstrand cross-link by a combination of nuclease P1 digestion with mass spectrometry.

    PubMed

    Wang, Yuesong; Wang, Yinsheng

    2003-11-15

    DNA interstrand cross-link reagents are among the most powerful agents for cancer treatment. Here we report a combined nuclease P1 digestion/mass spectrometry method for the structure elucidation of duplex oligodeoxynucleotides (ODNs) containing an interstrand cross-link. Our results demonstrate that nuclease P1 digestion of a double-stranded ODN containing an interstrand cross-link (ICL) of 4,5',8-trimethylpsoralen or mitomycin C gives a tetranucleotide bearing the cross-linked nucleobase moiety. Product ion spectra of the deprotonated ions of the tetranucleotides provide information about the structure of the cross-link. Furthermore, product-ion spectra of tetranucleotides containing two orientation isomers of mitomycin C interstrand cross-link are distinctive. We believe that the method described in this paper can be generally applicable for investigating the structures of other DNA ICLs.

  19. Light diffusing fiber optic chamber

    DOEpatents

    Maitland, Duncan J.

    2002-01-01

    A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

  20. Dislocation Diffusion in Metallic Materials

    DTIC Science & Technology

    2011-09-08

    DATES COVERED (From - To) April 1,2007-March 31, 2010 4. TITLE AND SUBTITLE Dislocation Diffusion in Metallic Materials 5a. CONTRACT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT The goals of this project were: (1) perform a fundamental study of atomic diffusion along dislocation cores in metals and...alloys, (2) develop new methods for the calculation of dislocation diffusion coefficients as functions of temperature and chemical composition and (3

  1. The period ratio P1/P2 of torsional Alfvén waves with steady flows in spicules

    NASA Astrophysics Data System (ADS)

    Ebadi, H.; Shahmorad, S.; Vasheghani Farahani, S.

    2016-04-01

    The aim here is to model the standing torsional oscillations in solar spicules in the presence of density stratification, magnetic field expansion, and steady flows. By implementing cylindrical geometry, the eigenfrequencies, eigenfunctions, and the period ratio P1/P2 of these waves is obtained for finite plasma-β. The shifts created by the steady flow justifies the divergence of the observed period ratio for the first and second periods from the number 2.

  2. Characterization of the human T cell response to rye grass pollen allergens Lol p 1 and Lol p 5.

    PubMed

    Burton, M D; Papalia, L; Eusebius, N P; O'Hehir, R E; Rolland, J M

    2002-12-01

    Knowledge of dominant T cell epitopes of major allergens recognized by allergic individuals is required to improve efficacy and safety of allergen immunotherapy. Rye grass pollen (RGP) is the most important source of seasonal aeroallergens in temperate climates and Lol p 1 and Lol p 5 are the two major IgE-reactive allergens. This study aimed to characterize the T cell response to these allergens using a large panel of RGP-sensitive individuals. Short-term RGP-specific T cell lines (TCL) were generated from 38 RGP-sensitive subjects and stimulated with Lol p 1 and/or Lol p 5 allergens and synthetic 20-mer peptides. Proliferative responses were determined by 3H-thymidine uptake and IL-5 and IFN-gamma in culture supernatants analysed by ELISA. Of 17 subjects tested for reactivity to both allergens 16 (94%) responded to Lol p 1 and/or Lol p 5, establishing these as major T cell-reactive allergens. Sites of T cell reactivity were spread throughout the allergen molecules but regions of high reactivity were found. For Lol p 1 these spanned residues 19-38, 109-128, 154-173, 190-209, and for Lol p 5 37-56, 100-119, 145-164, 154-173, 190-209, 217-236 and 226-245. IL-5 and IFN-gamma were produced by T cells cultured with proliferation-inducing peptides. T cell responses to RGP major allergens have been extensively characterized, providing fundamental information for developing T cell-targeted immunotherapy for RGP allergy.

  3. B:2a:p1.5 meningococcal strains likely arisen from capsular switching event still spreading in Spain.

    PubMed

    Castilla, Jesús; Vázquez, Julio A; Salcedo, Celia; García Cenoz, Manuel; García Irure, José Javier; Torroba, Luis; Beristain, Xabier; Abad, Raquel; Barricarte, Aurelio

    2009-02-01

    Eighteen clustered cases of meningococcal disease associated with B:2a:P1.5 strains doubled the annual incidence up to 4.3 x 10(5) in Navarra, Spain, in 2007. Eleven percent of cases were fatalities, and 74% of cases were individuals 10 to 24 years old. This is the third cluster associated with this strain in northern Spain since 2001.

  4. Filled and empty states of Zn-TPP films deposited on Fe(001)-p(1×1)O

    PubMed Central

    Calloni, Alberto; Yivlialin, Rossella; Picone, Andrea; Bottegoni, Federico; Finazzi, Marco

    2016-01-01

    Zn-tetraphenylporphyrin (Zn-TPP) was deposited on a single layer of metal oxide, namely an Fe(001)-p(1×1)O surface. The filled and empty electronic states were measured by means of UV photoemission and inverse photoemission spectroscopy on a single monolayer and a 20 monolayer thick film. The ionization energy and the electron affinity of the organic film were deduced and the interface dipole was determined and compared with data available in the literature. PMID:28144503

  5. A designed P1 cysteine mimetic for covalent and non-covalent inhibitors of HCV NS3 protease.

    PubMed

    Narjes, Frank; Koehler, Konrad F; Koch, Uwe; Gerlach, Benjamin; Colarusso, Stefania; Steinkühler, Christian; Brunetti, Mirko; Altamura, Sergio; De Francesco, Raffaele; Matassa, Victor G

    2002-02-25

    The difluoromethyl group was designed by computational chemistry methods as a mimetic of the canonical P1 cysteine thiol for inhibitors of the hepatitis C virus NS3 protease. This modification led to the development of competitive, non-covalent inhibitor 4 (K(i) 30 nM) and reversible covalent inhibitors (6, K(i) 0.5 nM; and 8 K*(i) 10 pM).

  6. Synthesis of Zeolites Na-P1 from South African Coal Fly Ash: Effect of Impeller Design and Agitation

    PubMed Central

    Mainganye, Dakalo; Ojumu, Tunde Victor; Petrik, Leslie

    2013-01-01

    South African fly ash has been shown to be a useful feedstock for the synthesis of some zeolites. The present study focuses on the effect of impeller design and agitation rates on the synthesis of zeolite Na-P1 which are critical to the commercialization of this product. The effects of three impeller designs (4-flat blade, Anchor and Archimedes screw impellers) and three agitation speeds (150, 200 and 300 rpm) were investigated using a modified previously reported synthesis conditions; 48 hours of ageing at 47 °C and static hydrothermal treatment at 140 °C for 48 hours. The experimental results demonstrated that the phase purity of zeolite Na-P1 was strongly affected by the agitation rate and the type of impeller used during the ageing step of the synthesis process. Although zeolite Na-P1 was synthesized with a space time yield (STY) of 15 ± 0.4 kg d−1m−3 and a product yield of 0.98±0.05 g zeolites/g fly ash for each impeller at different agitation speeds, zeolite formation was assessed to be fairly unsuccessful in some cases due the occurrence of undissolved mullite and/or the formation of impurities such as hydroxysodalite with the zeolitic product. This study also showed that a high crystalline zeolite Na-P1 can be synthesized from South African coal fly ash using a 4-flat blade impeller at an agitation rate of 200 rpm during the ageing step at 47 °C for 48 hours followed by static hydrothermal treatment at 140 °C for 48 hours. PMID:28809261

  7. Climatic and lake temperature data for Wetland P1, Cottonwood Lake Area, Stutsman County, North Dakota, 1982-87

    USGS Publications Warehouse

    Parkhurst, Renee S.; Sturrock, A.M.; Rosenberry, D.O.; Winter, T.C.

    1995-01-01

    Research on the hydrology of Wetland P1 and the Cottonwood Lake Area includes the study of evaporation. Presented here in a graphical format are those data collected during the open-water seasons of 1982-87 that were needed for energy- budget and mass-transfer evaporation studies. The data include air temperatures, water surface and lake-bottom temperatures, windspeed, radiation, humidity, and precipitation. Data were collected at a raft station and two land stations.

  8. Multilane driven diffusive systems

    NASA Astrophysics Data System (ADS)

    Curatolo, A. I.; Evans, M. R.; Kafri, Y.; Tailleur, J.

    2016-03-01

    We consider networks made of parallel lanes along which particles hop according to driven diffusive dynamics. The particles also hop transversely from lane to lane, hence indirectly coupling their longitudinal dynamics. We present a general method for constructing the phase diagram of these systems which reveals that in many cases their physics reduce to that of single-lane systems. The reduction to an effective single-lane description legitimizes, for instance, the use of a single TASEP to model the hopping of molecular motors along the many tracks of a single microtubule. Then, we show how, in quasi-2D settings, new phenomena emerge due to the presence of non-zero transverse currents, leading, for instance, to strong ‘shear localization’ along the network.

  9. Anomalous ballistic diffusion

    NASA Astrophysics Data System (ADS)

    Havlin, Shlomo; Bunde, Armin; Stanley, H. Eugene

    1986-07-01

    We introduce a novel two-component random network. Unit resistors are placed at random along the bonds of a pure superconducting linear chain, with the distance l between successive resistors being chosen from the distribution P(l)~l-(α+1) where α>0 is a tunable parameter. We study the transport exponents dw and ζ~ defined by ~t2/dw and ρ~Lζ~, where is the mean-square displacement, ρ the resistivity, and L the system size. We find that for α>=1 both dw and ζ~ stick at their value for a nonzero concentration of resistors. For α<1 they vary continuously with α: dw=2α and ζ~=α. In the presence of a bias field, we find dw=α. This is the first exactly soluble model displaying ``anomalous ballistic diffusion,'' which we interpret physically in terms of a Lévy-flight random walk on a linear chain lattice.

  10. Fractional chemotaxis diffusion equations.

    PubMed

    Langlands, T A M; Henry, B I

    2010-05-01

    We introduce mesoscopic and macroscopic model equations of chemotaxis with anomalous subdiffusion for modeling chemically directed transport of biological organisms in changing chemical environments with diffusion hindered by traps or macromolecular crowding. The mesoscopic models are formulated using continuous time random walk equations and the macroscopic models are formulated with fractional order differential equations. Different models are proposed depending on the timing of the chemotactic forcing. Generalizations of the models to include linear reaction dynamics are also derived. Finally a Monte Carlo method for simulating anomalous subdiffusion with chemotaxis is introduced and simulation results are compared with numerical solutions of the model equations. The model equations developed here could be used to replace Keller-Segel type equations in biological systems with transport hindered by traps, macromolecular crowding or other obstacles.

  11. Parallel FoxP1 and FoxP2 expression in songbird and human brain predicts functional interaction.

    PubMed

    Teramitsu, Ikuko; Kudo, Lili C; London, Sarah E; Geschwind, Daniel H; White, Stephanie A

    2004-03-31

    Humans and songbirds are two of the rare animal groups that modify their innate vocalizations. The identification of FOXP2 as the monogenetic locus of a human speech disorder exhibited by members of the family referred to as KE enables the first examination of whether molecular mechanisms for vocal learning are shared between humans and songbirds. Here, in situ hybridization analyses for FoxP1 and FoxP2 in a songbird reveal a corticostriatal expression pattern congruent with the abnormalities in brain structures of affected KE family members. The overlap in FoxP1 and FoxP2 expression observed in the songbird suggests that combinatorial regulation by these molecules during neural development and within vocal control structures may occur. In support of this idea, we find that FOXP1 and FOXP2 expression patterns in human fetal brain are strikingly similar to those in the songbird, including localization to subcortical structures that function in sensorimotor integration and the control of skilled, coordinated movement. The specific colocalization of FoxP1 and FoxP2 found in several structures in the bird and human brain predicts that mutations in FOXP1 could also be related to speech disorders.

  12. The viral capping enzyme nsP1: a novel target for the inhibition of chikungunya virus infection

    PubMed Central

    Delang, L.; Li, C.; Tas, A.; Quérat, G.; Albulescu, I. C.; De Burghgraeve, T.; Guerrero, N. A. Segura; Gigante, A.; Piorkowski, G.; Decroly, E.; Jochmans, D.; Canard, B.; Snijder, E. J.; Pérez-Pérez, M. J.; van Hemert, M. J.; Coutard, B.; Leyssen, P.; Neyts, J.

    2016-01-01

    The chikungunya virus (CHIKV) has become a substantial global health threat due to its massive re-emergence, the considerable disease burden and the lack of vaccines or therapeutics. We discovered a novel class of small molecules ([1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones) with potent in vitro activity against CHIKV isolates from different geographical regions. Drug-resistant variants were selected and these carried a P34S substitution in non-structural protein 1 (nsP1), the main enzyme involved in alphavirus RNA capping. Biochemical assays using nsP1 of the related Venezuelan equine encephalitis virus revealed that the compounds specifically inhibit the guanylylation of nsP1. This is, to the best of our knowledge, the first report demonstrating that the alphavirus capping machinery is an excellent antiviral drug target. Considering the lack of options to treat CHIKV infections, this series of compounds with their unique (alphavirus-specific) target offers promise for the development of therapy for CHIKV infections. PMID:27545976

  13. A 1.6-Mb P1-based physical map of the Down syndrome region on chromosome 21

    SciTech Connect

    Ohira, Miki; Suzuki, Kazunobu |; Ichikawa, Hitoshi

    1996-04-01

    The Down Syndrome (DS) region on chromosome 21, which is responsible for the main features of DS such as characteristic facial features, a congenital heart defect, and mental retardation, has been defined by molecular analysis of DS patients with partial trisomy 21. The 2.5-Mb region around the marker D21S55 between D21S17 and ERG in 21q22 is thought to be important, although contributions of other regions cannot be excluded. In this region, we focused on a 1.6-Mb region between a NotI site, LA68 (D21S396, which is mapped distal to D21S17) and ERG, because analysis of a Japanese DS family with partial trisomy 21 revealed that the proximal border of its triplicated region was distal to LA68. We constructed P1 contigs with 46 P1 clones covering more than 95% of the 1.6-Mb region. A high-resolution restriction map using BamHI was also constructed for more details analysis. Our P1 contig map supplements other physical maps previously reported and provides useful materials for further analysis including isolation and sequencing of the DS region. 31 refs., 7 figs., 1 tab.

  14. Genome sequence of the phage clP1, which infects the beer spoilage bacterium Pediococcus damnosus.

    PubMed

    Kelly, David; O'Sullivan, Orla; Mills, Susan; McAuliffe, Olivia; Ross, R Paul; Neve, Horst; Coffey, Aidan

    2012-08-01

    Pediococcus damnosus (P. damnosus) bacteriophage (phage) clP1 is a novel virulent phage isolated from a municipal sewage sample collected in Southern Ireland. This phage infects the beer spoilage strain P. damnosus P82 which was isolated from German breweries. Sequencing of the phage has revealed a linear double stranded DNA genome of 38,013 base pairs (bp) with an overall GC content of 47.6%. Fifty seven open reading frames (ORFs) were identified of which 30 showed homology to previously sequenced proteins, and as a consequence 20 of these were assigned predicted functions. The majority of genes displayed homology with genes from the Lactobacillus plantarum phage phiJL-1. All genes were located on the same coding strand and in the same orientation. Morphological characterisation placed phage clP1 as a member of the Siphoviridae family with an isometric head (59 nm diameter) and non-contractile tail (length 175 nm; diameter 10nm. Interestingly, the phage clP1 genome was found to share very limited identity with other phage genome sequences in the database, and was hence considered unique. This was highlighted by the genome organisation which differed slightly to the consensus pattern of genomic organisation usually found in Siphoviridae phages. With the genetic machinery present for a lytic lifecycle and the absence of potential endotoxin factors, this phage may have applications in the biocontrol of beer spoilage bacteria. To our knowledge, this study represents the first reported P. damnosus phage genome sequence.

  15. Global ocean tides. Part VII. The diurnal principal solar tide (P1), atlas of tidal charts and maps. Final report

    SciTech Connect

    Schwiderski, E.W.

    1981-05-01

    In Part I (Schwiderski, 1978a) of this report, a unique hydrodynamical interpolation technique was introduced, extensively tested, and evaluated in order to compute partial global ocean tides in great detail and with a high degree of accuracy. This novel method has been applied to construct the diurnal principal solar (P1) ocean tide with a relative accuracy of better than 5 cm anywhere in the open oceans. The resulting tidal amplitudes and phases are tabulated on a 1 deg X 1 deg grid system in an atlas of 42 deg X 71 deg overlapping charts covering the whole oceanic globe. A corresponding atlas of global corange and cotidal maps is included to provide the reader with a quick general overview of the major tidal phenomena. The specifying hydrodynamical parameters of the model are listed along with quoted sources of empirical tide data, and significant tidal features are explained and discussed. As expected, since the periods of the diurnal tides P1 (24.07h) and K1 (23.93 h) differ by only 0.14 h, these two tides resemble very closely each other (compare Part IV). Significant differences occur only in regions of rapid tidal variations. Of course, P1 resembles also the diurnal 01 tide but to a visibly lesser degree (see Part V).

  16. The viral capping enzyme nsP1: a novel target for the inhibition of chikungunya virus infection.

    PubMed

    Delang, L; Li, C; Tas, A; Quérat, G; Albulescu, I C; De Burghgraeve, T; Guerrero, N A Segura; Gigante, A; Piorkowski, G; Decroly, E; Jochmans, D; Canard, B; Snijder, E J; Pérez-Pérez, M J; van Hemert, M J; Coutard, B; Leyssen, P; Neyts, J

    2016-08-22

    The chikungunya virus (CHIKV) has become a substantial global health threat due to its massive re-emergence, the considerable disease burden and the lack of vaccines or therapeutics. We discovered a novel class of small molecules ([1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones) with potent in vitro activity against CHIKV isolates from different geographical regions. Drug-resistant variants were selected and these carried a P34S substitution in non-structural protein 1 (nsP1), the main enzyme involved in alphavirus RNA capping. Biochemical assays using nsP1 of the related Venezuelan equine encephalitis virus revealed that the compounds specifically inhibit the guanylylation of nsP1. This is, to the best of our knowledge, the first report demonstrating that the alphavirus capping machinery is an excellent antiviral drug target. Considering the lack of options to treat CHIKV infections, this series of compounds with their unique (alphavirus-specific) target offers promise for the development of therapy for CHIKV infections.

  17. Positively Selected Codons in Immune-Exposed Loops of the Vaccine Candidate OMP-P1 of Haemophilus influenzae

    PubMed Central

    van Putten, Jos P. M.

    2007-01-01

    The high levels of variation in surface epitopes can be considered as an evolutionary hallmark of immune selection. New computational tools enable analysis of this variation by identifying codons that exhibit high rates of amino acid changes relative to the synonymous substitution rate. In the outer membrane protein P1 of Haemophilus influenzae, a vaccine candidate for nontypeable strains, we identified four codons with this attribute in domains that did not correspond to known or assumed B- and T-cell epitopes of OMP-P1. These codons flank hypervariable domains and do not appear to be false positives as judged from parsimony and maximum likelihood analyses. Some closely spaced positively selected codons have been previously considered part of a transmembrane domain, which would render this region unsuited for inclusion in a vaccine. Secondary structure analysis, three-dimensional structural database searches, and homology modeling using FadL of E. coli as a structural homologue, however, revealed that all positively selected codons are located in or near extracellular looping domains. The spacing and level of diversity of these positively selected and exposed codons in OMP-P1 suggest that vaccine targets based on these and conserved flanking residues may provide broad coverage in H. influenzae. Electronic Supplementary Material The online version of this article (doi:10.1007/s00239-006-0021-2) contains supplementary material, which is available to authorized users. PMID:17479342

  18. Diffusion in Jammed Particle Packs.

    PubMed

    Bolintineanu, Dan S; Grest, Gary S; Lechman, Jeremy B; Silbert, Leonardo E

    2015-08-21

    Using random walk simulations we explore diffusive transport through monodisperse sphere packings over a range of packing fractions ϕ in the vicinity of the jamming transition at ϕ(c). Various diffusion properties are computed over several orders of magnitude in both time and packing pressure. Two well-separated regimes of normal "Fickian" diffusion, where the mean squared displacement is linear in time, are observed. The first corresponds to diffusion inside individual spheres, while the latter is the long-time bulk diffusion. The intermediate anomalous diffusion regime and the long-time value of the diffusion coefficient are both shown to be controlled by particle contacts, which in turn depend on proximity to ϕ(c). The time required to recover normal diffusion t* scales as (ϕ-ϕ(c))(-0.5) and the long-time diffusivity D(∞)∼(ϕ-ϕ(c))0.5, or D(∞)∼1/t*. It is shown that the distribution of mean first passage times associated with the escape of random walkers between neighboring particles controls both t* and D(∞) in the limit ϕ→ϕ(c).

  19. Lateral Diffusion in an Archipelago

    PubMed Central

    Saxton, Michael J.

    1982-01-01

    Lateral diffusion of molecules in lipid bilayer membranes can be hindered by the presence of impermeable domains of gel-phase lipid or of proteins. Effective-medium theory and percolation theory are used to evaluate the effective lateral diffusion constant as a function of the area fraction of fluid-phase lipid and the permeability of the obstructions to the diffusing species. Applications include the estimation of the minimum fraction of fluid lipid needed for bacterial growth, and the enhancement of diffusion-controlled reactions by the channeling effect of solid patches of lipid. PMID:7052153

  20. COMPLEX DIFFUSION ON IMAGE GRAPHS

    PubMed Central

    Seo, Dohyung; Vemuri, Baba C

    2009-01-01

    Complex diffusion was introduced in image processing literature as a means to achieve simultaneous denoising and enhancement of scalar valued images. In this paper, we present a novel geometric framework for achieving complex diffusion on color images expressed as image graphs. In this framework, we develop a new variational formulation for achieving complex diffusion. This formulation involves a modified harmonic map functional and is quite distinct from the Polyakov action described in earlier work by Sochen et al. Our formulation provides a framework for simultaneous (feature preserving) denoising and enhancement. We present results of comparison between the complex diffusion, and Beltrami flow all in the image graph framework. PMID:20490365

  1. Enthalpy Diffusion in Multicomponent Flows

    SciTech Connect

    Cook, A W

    2009-01-20

    The conclusions of this paper are: (1) Enthalpy diffusion preserves the second law. (2) Euler solvers will not produce correct temperatures in mixing regions. (3) Navier-Stokes solvers will only produce correct temperatures if q{sub d} is included. (4) Errors from neglecting enthalpy diffusion are most severe when differences in molecular weights are large. (5) In addition to temperature, enthalpy diffusion affects density, dilatation and other fields in subtle ways. (6) Reacting flow simulations that neglect the term are a dubious proposition. (7) Turbulence models for RANS and LES closures should preserve consistency between energy and species diffusion.

  2. REMOVAL: P1_Abstract.

    PubMed

    2017-03-01

    This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). Due to an administrative error, an issue was accidentally published here. This has now been removed. The publisher apologises for any inconvenience this may cause. Copyright © 2017.

  3. Altered gene expression patterns of innate and adaptive immunity pathways in transgenic rainbow trout harboring Cecropin P1 transgene.

    PubMed

    Lo, Jay H; Lin, Chun-Mean; Chen, Maria J; Chen, Thomas T

    2014-10-11

    We have recently developed several homozygous families of transgenic rainbow trout harbouring cecropin P1 transgene. These fish exhibit resistance characteristic to infection by Aeromonas salmonicida and infectious hematopoietic necrosis virus (IHNV). In our earlier studies we have reported that treatment of a rainbow trout macrophage cell line (RTS11) with a linear cationic α-helical antimicrobial peptide (e.g., cecropin B) resulted in elevated levels of expression of two pro-inflammatory relevant genes (e.g., IL-1β and COX-2). Therefore, we hypothesized that in addition to the direct antimicrobial activity of cecropin P1 in the disease resistant transgenic rainbow trout, this antimicrobial peptide may also affect the expression of immune relevant genes in the host. To confirm this hypothesis, we launched a study to determine the global gene expression profiles in three immune competent organs of cecropin P1 transgenic rainbow trout by using a 44k salmonid microarray. From the microarray data, a total of 2480 genes in the spleen, 3022 in the kidney, and 2102 in the liver were determined as differentially expressed genes (DEGs) in the cecropin P1 transgenic rainbow trout when compared to the non-transgenics. There were 478 DEGs in common among three tissues. Enrichment analyses conducted by two different bioinformatics tools revealed a tissue specific profile of functional pathway perturbation. Many of them were directly related to innate immune system such as phagocytosis, lysosomal processing, complement activation, antigen processing/presentation, and leukocyte migration. Perturbation of other biological functions that might contribute indirectly to host immunity was also observed. The gene product of cecropin P1 transgene produced in the disease resistant transgenic rainbow trout not only can kill the pathogens directly but also exert multifaceted immunomodulatory properties to boost host immunity. The identified genes involved in different pathways related

  4. A high-precision chemical abundance analysis of the HAT-P-1 stellar binary: constraints on planet formation

    NASA Astrophysics Data System (ADS)

    Liu, F.; Asplund, M.; Ramírez, I.; Yong, D.; Meléndez, J.

    2014-07-01

    We present a high-precision, differential elemental abundance analysis of the HAT-P-1 stellar binary based on high-resolution, high signal-to-noise ratio Keck/HIRES (High Resolution Echelle Spectrometer) spectra. The secondary star in this double system is known to host a transiting giant planet while no planets have yet been detected around the primary star. The derived metallicities ([Fe/H]) of the primary and secondary stars are identical within the errors: 0.146 ± 0.014 dex (σ = 0.033 dex) and 0.155 ± 0.007 dex (σ = 0.023 dex), respectively. Extremely precise differential abundance ratios of 23 elements have been measured (mean error of σ([X/Fe]) = 0.013 dex) and are found to be indistinguishable between the two stars: Δ[X/Fe] (secondary - primary) = +0.001 ± 0.006 dex (σ = 0.008 dex). The striking similarity in the chemical composition of the two stellar components in HAT-P-1 is contrary to the possible 0.04 dex level difference seen in 16 Cyg A+B, which also hosts a giant planet, at least three times more massive than the one around HAT-P-1 secondary star. We conclude that the presence of giant planets does not necessarily imply differences in the chemical compositions of the host stars. The elemental abundances of each star in HAT-P-1 relative to the Sun show an identical, positive correlation with the condensation temperature of the elements; their abundance patterns are thus very similar to those observed in the majority of solar twins. In view of the Meléndez et al. interpretation of the peculiar solar abundance pattern, we conclude that HAT-P-1 experienced less efficient formation of terrestrial planets than the Sun. This is in line with the expectation that the presence of close-in giant planets preventing the formation or survival of terrestrial planets.

  5. Influence of ETR-p1/f1 antisense peptide on endothelin-induced constriction in rat renal arcuate arteries

    PubMed Central

    Wu, Xiaochun; Richards, Nicholas T; Johns, Edward J; Kohsaka, Takeo; Nakamura, Akio; Okada, Hidechika

    1997-01-01

    This study set out to examine the endothelin receptor subtypes mediating vasoconstriction in the rat renal arcuate artery. This was done in isolated vessels 120–200 μm in diameter, incubated with a selective agonist and the novel ‘antisense' peptide to part of the human endothelinA receptor. Groups of vessels (n=6) were incubated with increasing concentrations of endothelin-1 (ET-1), from 1 to 100 nM, which caused a 65% maximal contraction at the highest dose with an pEC50 of 8.16±0.11 M. By contrast, in six other vessels sarafotoxin 6c over the same dose range gave a minimal contraction (around 5% of maximum). Preincubation of six vessels with the antisense peptide ETR p1/f1 at 1 μM had no effect on the ET-1 induced vasoconstriction, in terms of displacement of the concentration-response curve or the maximal tension achieved by the agonist. In the six vessels exposed to 4 μM ETR p1/f1, there was a significant shift of the concentration-response curve and a lower pEC50 at 7.78±0.09 M (P<0.05). At the highest concentrations of ETR p1/f1, there was a marked suppression of all responses to ET-1, which at the maximal concentrations tested, 0.1 μM, only reached some 10% of the maximal achievable contraction. Increasing ET-1 concentrations up to 2 μM in vessels incubated with 40 μM ETR-p1/f1 showed that the blockade could be overcome and that the relationship was shifted to the right (P<0.001) by approximately one log unit with a pEC50 of 7.13±0.11 M. A Schild plot of the data indicated the antagonist to be acting competitively at a single population of receptors. At the highest concentrations tested, 40 μM, ETR-p1/f1 had no effect on noradrenaline-induced contractions, indicating a lack of non-specific actions. Together, these data suggest that at the rat renal arcuate artery the endothelinA receptor is the predominant functional receptor mediating contraction. Furthermore, this study has shown the potential usefulness of this novel

  6. Facilitated Diffusion of Transcription Factor Proteins with Anomalous Bulk Diffusion.

    PubMed

    Liu, Lin; Cherstvy, Andrey G; Metzler, Ralf

    2017-02-16

    What are the physical laws of the diffusive search of proteins for their specific binding sites on DNA in the presence of the macromolecular crowding in cells? We performed extensive computer simulations to elucidate the protein target search on DNA. The novel feature is the viscoelastic non-Brownian protein bulk diffusion recently observed experimentally. We examine the influence of the protein-DNA binding affinity and the anomalous diffusion exponent on the target search time. In all cases an optimal search time is found. The relative contribution of intermittent three-dimensional bulk diffusion and one-dimensional sliding of proteins along the DNA is quantified. Our results are discussed in the light of recent single molecule tracking experiments, aiming at a better understanding of the influence of anomalous kinetics of proteins on the facilitated diffusion mechanism.

  7. Isotopic selectivity of surface diffusion: An activated diffusion model

    SciTech Connect

    Trowbridge, L.D.

    1989-11-01

    Gaseous diffusion systems are designed to separate UF{sub 6} isotopes by pumping gas through a microporous membrane. A second mode of transport exists in barrier, namely that of surface diffusion. The primary purpose of this report is to illustrate, with a very simple model, the qualitative behavior of surface diffusion in a way intended to retain the physical insight into how this flow will behave, and to show how it might manifest itself when observed in combination with gas-phase flow. The model developed uses general concepts of activated diffusion and the Langmuir adsorption isotherm to examine surface diffusion from the standpoint of characteristics important to isotope separation, namely the conductivity and isotopic selectivity of surface flow, as a function of temperature, pressure, and adsorption energy. 25 refs., 14 figs., 5 tabs.

  8. Osmosis and Diffusion Conceptual Assessment

    ERIC Educational Resources Information Center

    Fisher, Kathleen M.; Williams, Kathy S.; Lineback, Jennifer Evarts

    2011-01-01

    Biology student mastery regarding the mechanisms of diffusion and osmosis is difficult to achieve. To monitor comprehension of these processes among students at a large public university, we developed and validated an 18-item Osmosis and Diffusion Conceptual Assessment (ODCA). This assessment includes two-tiered items, some adopted or modified…

  9. Osmosis and Diffusion Conceptual Assessment

    ERIC Educational Resources Information Center

    Fisher, Kathleen M.; Williams, Kathy S.; Lineback, Jennifer Evarts

    2011-01-01

    Biology student mastery regarding the mechanisms of diffusion and osmosis is difficult to achieve. To monitor comprehension of these processes among students at a large public university, we developed and validated an 18-item Osmosis and Diffusion Conceptual Assessment (ODCA). This assessment includes two-tiered items, some adopted or modified…

  10. Demonstrating Diffusion: Why the Confusion?

    ERIC Educational Resources Information Center

    Panizzon, Debra Lee

    1998-01-01

    Examines the principles of diffusion and how it may be confused with convection. Suggests that educators may be misleading students and clouding their understanding of the process. Provides two contemporary examples to explain the process of diffusion and how it differs from convection. (Author/CCM)

  11. Fractional diffusion on bounded domains

    DOE PAGES

    Defterli, Ozlem; D'Elia, Marta; Du, Qiang; ...

    2015-03-13

    We found that the mathematically correct specification of a fractional differential equation on a bounded domain requires specification of appropriate boundary conditions, or their fractional analogue. In this paper we discuss the application of nonlocal diffusion theory to specify well-posed fractional diffusion equations on bounded domains.

  12. Diffusion in jammed particle packs

    NASA Astrophysics Data System (ADS)

    Bolintineanu, Dan S.; Silbert, Leonardo E.; Grest, Gary S.; Lechman, Jeremy B.

    2015-03-01

    Diffusive transport in jammed particle packs is of interest for a number of applications, as well as being a potential indicator of structural properties near the jamming point. To this end, we report stochastic simulations of equilibrium diffusion through monodisperse sphere packs near the jamming point in the limit of a perfectly insulating surrounding medium. The time dependence of various diffusion properties is resolved over several orders of magnitude. Two time regimes of expected Fickian diffusion are observed, separated by an intermediate regime of anomalous diffusion. This intermediate regime grows as the particle volume fraction approaches the critical jamming transition. The diffusion behavior is fully controlled by the extent of the contacts between neighboring particles, which in turn depend on proximity to the jamming point. In particular, the mean first passage time associated with the escape of random walkers between neighboring particles is shown to control both the time to recover Fickian diffusion and the long time diffusivity. Scaling laws are established that relate these quantities to the difference between the actual and critical jamming volume fractions. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE- AC04-94AL85000.

  13. Demonstrating Diffusion: Why the Confusion?

    ERIC Educational Resources Information Center

    Panizzon, Debra Lee

    1998-01-01

    Examines the principles of diffusion and how it may be confused with convection. Suggests that educators may be misleading students and clouding their understanding of the process. Provides two contemporary examples to explain the process of diffusion and how it differs from convection. (Author/CCM)

  14. Preliminary Investigation of Supersonic Diffusers

    DTIC Science & Technology

    1945-05-01

    No. L5D20 This pressure was measured with a large mercury manometer . The total ’head after diffusion can be assumed equal to the static pressure at...of the entering kinetic energy. A mercury manometer was used to measure the difference between the total heads before and after diffusion. ‘J!hesetwo

  15. Selected Dissemination/Diffusion Strategies.

    ERIC Educational Resources Information Center

    Schmitt, Marshall L.

    This analysis of selected diffusion and dissemination methods used by developer-demonstrator projects in the National Diffusion Network discusses strategies under the following headings: managing the project, developing materials, disseminating information, conducting awareness sessions, training personnel, using certified trainers, providing…

  16. Fractional diffusion on bounded domains

    SciTech Connect

    Defterli, Ozlem; D'Elia, Marta; Du, Qiang; Gunzburger, Max Donald; Lehoucq, Richard B.; Meerschaert, Mark M.

    2015-03-13

    We found that the mathematically correct specification of a fractional differential equation on a bounded domain requires specification of appropriate boundary conditions, or their fractional analogue. In this paper we discuss the application of nonlocal diffusion theory to specify well-posed fractional diffusion equations on bounded domains.

  17. Teaching Diffusion with a Coin

    ERIC Educational Resources Information Center

    Haddad, Hamilton; Baldo, Marcus Vinicius Chrysostomo

    2010-01-01

    In this article, the authors describe an inexpensive and simple way to make students intuitively experience the probabilistic nature and nonorientated motion of diffusing particles. This understanding allows students to realize why diffusion works so well over short distances and becomes increasingly and rapidly less effective as the distances…

  18. Gas Diffusion in the CNS.

    PubMed

    Rodriguez-Grande, Beatriz; Konsman, Jan-Pieter

    2017-05-15

    Gases have been long known to have essential physiological functions in the CNS such as respiration or regulation of vascular tone. Since gases have been classically considered to freely diffuse, research in gas biology has so far focused on mechanisms of gas synthesis and gas reactivity, rather than gas diffusion and transport. However, the discovery of gas pores during the last two decades and the characterization of diverse diffusion patterns through different membranes has raised the possibility that modulation of gas diffusion is also a physiologically relevant parameter. Here we review the means of gas movement into and within the brain through "free" diffusion and gas pores, notably aquaporins, discussing the role that gas diffusion may play in the modulation of gas function. We highlight how diffusion is relevant to neuronal signaling, volume transmission, and cerebrovascular control in the case of NO, one of the most extensively studied gases. We point out how facilitated transport can be especially relevant for gases with low permeability in lipid membranes like NH3 and discuss the possible implications of NH3 -permeable channels in physiology and hyperammonemic encephalopathy. We identify novel research questions about how modulation of gas diffusion could intervene in CNS pathologies. This emerging area of research can provide novel and interesting insights in the field of gas biology. © 2017 Wiley Periodicals, Inc.

  19. The Diffusion of New Math.

    ERIC Educational Resources Information Center

    Ready, Patricia M.

    The life cycle of "new math" is fertile ground for the study of the diffusion of an innovation. New math arrived in 1958 to save the day for America after the Soviet Union launched Sputnik, the first successful space flight in 1957. In a period of 16 years an entire diffusion cycle was completed throughout the entire educational system…

  20. Portable vapor diffusion coefficient meter

    DOEpatents

    Ho, Clifford K.

    2007-06-12

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  1. Diffusion on ruffled membrane surfaces.

    PubMed

    Naji, Ali; Brown, Frank L H

    2007-06-21

    We present a position Langevin equation for overdamped particle motion on rough two-dimensional surfaces. A Brownian dynamics algorithm is suggested to evolve this equation numerically, allowing for the prediction of effective (projected) diffusion coefficients over corrugated surfaces. In the case of static surface roughness, we find that a simple area-scaling prediction for the projected diffusion coefficient leads to seemingly quantitative agreement with numerical results. To study the effect of dynamic surface evolution on the diffusive process, we consider particle diffusion over a thermally fluctuating elastic membrane. Surface fluctuation has the effect of increasing the effective diffusivity toward a limiting annealed-surface value discussed previously. We argue that protein motion over cell surfaces spans a variety of physical regimes, making it impossible to identify a single approximation scheme appropriate to all measurements of interest.

  2. Enthalpy Diffusion in Multicomponent Flows

    SciTech Connect

    Cook, A W

    2008-11-12

    The enthalpy diffusion flux in the multicomponent energy equation is a well known yet frequently neglected term. It accounts for energy changes, associated with compositional changes, resulting from species diffusion. Enthalpy diffusion is important in flows where significant mixing occurs between species of dissimilar molecular weight. The term plays a critical role in preventing local violations of the entropy condition. In simulations of nonpremixed combustion, omission of the enthalpy flux can lead to anomalous temperature gradients, which may cause mixing regions to exceed ignition conditions. The term can also play a role in generating acoustic noise in turbulent mixing layers. Euler solvers that rely on numerical diffusion to mix fluids cannot accurately predict the temperature in mixed regions. On the other hand, Navier-Stokes solvers that incorporate enthalpy diffusion can provide much more accurate results.

  3. Diffusion of polymer gel implants.

    PubMed

    Davis, B K

    1974-08-01

    Crosslinked polyacrylamide and polyvinylpyrrolidone gels have been used to subcutaneously implant (125)I-labeled immunoglobulin, (125)I-labeled luteinizing hormone, (125)I-labeled bovine serum albumin, (125)I-labeled insulin, [(3)H]prostaglandin F(2alpha), and Na(125)I into hamsters. From the rates of absorption of the solutes, their diffusion coefficients were determined. The diffusion coefficients showed a logarithmic dependence on implant polymer concentration and solute molecular weight. Release of the solutes from gel preparations incubated 10 mM phosphate buffer (pH 7.2) at 37 degrees revealed a similar relationship between solute diffusion coefficient, molecular weight, and the concentration of polymer. A general equation was derived that gives the expected diffusion coefficient of a substance in a polymer gel from its molecular weight, diffusion coefficient in solvent, and polymer concentration of the gel.

  4. Knudsen Diffusion in Silicon Nanochannels

    NASA Astrophysics Data System (ADS)

    Gruener, Simon; Huber, Patrick

    2008-02-01

    Measurements on helium and argon gas flow through an array of parallel, linear channels of 12 nm diameter and 200μm length in a single crystalline silicon membrane reveal a Knudsen diffusion type transport from 102 to 107 in Knudsen number Kn. The classic scaling prediction for the transport diffusion coefficient on temperature and mass of diffusing species, DHe∝T, is confirmed over a T range from 40 K to 300 K for He and for the ratio of DHe/DAr∝mAr/mHe. Deviations of the channels from a cylindrical form, resolved with electron microscopy down to subnanometer scales, quantitatively account for a reduced diffusivity as compared to Knudsen diffusion in ideal tubular channels. The membrane permeation experiments are described over 10 orders of magnitude in Kn, encompassing the transition flow regime, by the unified flow model of Beskok and Karniadakis.

  5. Ammonia diffusion through Nalophan™ bags.

    PubMed

    Sironi, Selena; Eusebio, Lidia; Dentoni, Licinia; Capelli, Laura; Del Rosso, Renato

    2014-01-01

    The aim of the work is to verify the diffusion rate of ammonia through the Nalophan™ film that constitutes the sampling bag, considering storage times ranging from 1 to 26 h. The ammonia decay over time was evaluated using gas-chromatography for the quantification of ammonia concentration inside the bag. The research assesses the roles of both of ammonia and water concentration gradients at the polymeric film interface on the diffusion process. The results show that both the ammonia concentration gradient and, in a less pronounced way, the water concentration gradient are the main 'engines' of ammonia diffusion. Double bags seem to represent a simple solution for preventing ammonia losses during storage. Another interesting result concerns the role of the bag surface on the ammonia diffusion rate: the higher the surface/volume (S/V) ratio, the higher the ammonia diffusion rate through the polymeric film.

  6. Heat transfer, diffusion, and evaporation

    NASA Technical Reports Server (NTRS)

    Nusselt, Wilhelm

    1954-01-01

    Although it has long been known that the differential equations of the heat-transfer and diffusion processes are identical, application to technical problems has only recently been made. In 1916 it was shown that the speed of oxidation of the carbon in iron ore depends upon the speed with which the oxygen of the combustion air diffuses through the core of gas surrounding the carbon surface. The identity previously referred to was then used to calculate the amount of oxygen diffusing to the carbon surface on the basis of the heat transfer between the gas stream and the carbon surface. Then in 1921, H. Thoma reversed that procedure; he used diffusion experiments to determine heat-transfer coefficients. Recently Lohrisch has extended this work by experiment. A technically very important application of the identity of heat transfer and diffusion is that of the cooling tower, since in this case both processes occur simultaneously.

  7. Diffusion in membranes: Toward a two-dimensional diffusion map

    NASA Astrophysics Data System (ADS)

    Toppozini, Laura; Garcia-Sakai, Victoria; Bewley, Robert; Dalgliesh, Robert; Perring, Toby; Rheinstädter, Maikel C.

    2015-01-01

    For decades, quasi-elastic neutron scattering has been the prime tool for studying molecular diffusion in membranes over relevant nanometer distances. These experiments are essential to our current understanding of molecular dynamics of lipids, proteins and membrane-active molecules. Recently, we presented experimental evidence from X-ray diffraction and quasi-elastic neutron scattering demonstrating that ethanol enhances the permeability of membranes. At the QENS 2014/WINS 2014 conference we presented a novel technique to measure diffusion across membranes employing 2-dimensional quasi-elastic neutron scattering. We present results from our preliminary analysis of an experiment on the cold neutron multi-chopper spectrometer LET at ISIS, where we studied the self-diffusion of water molecules along lipid membranes and have the possibility of studying the diffusion in membranes. By preparing highly oriented membrane stacks and aligning them horizontally in the spectrometer, our aim is to distinguish between lateral and transmembrane diffusion. Diffusion may also be measured at different locations in the membranes, such as the water layer and the hydrocarbon membrane core. With a complete analysis of the data, 2-dimensional mapping will enable us to determine diffusion channels of water and ethanol molecules to quantitatively determine nanoscale membrane permeability.

  8. Dim and diffuse

    NASA Image and Video Library

    2017-07-17

    Tucked away in the small northern constellation of Canes Venatici (The Hunting Dogs) is the galaxy NGC 4242, shown here as seen by the NASA/ESA Hubble Space Telescope. The galaxy lies some 30 million light-years from us. At this distance from Earth, actually not all that far on a cosmic scale, NGC 4242 is visible to anyone armed with even a basic telescope (as British astronomer William Herschel found when he discovered the galaxy in 1788). This image shows the galaxy’s bright centre and the surrounding dimmer and more diffuse “fuzz”. Despite appearing to be relatively bright in this image, studies have found that NGC 4242 is actually relatively dim (it has a moderate-to-low surface brightness and low luminosity) and also supports a low rate of star formation. The galaxy also seems to have a weak bar of stars cutting through its asymmetric centre, and a very faint and poorly-defined spiral structure throughout its disc. But if NGC 4242 is not all that remarkable, as with much of the Universe, it is still a beautiful and ethereal sight.

  9. Hydrogen diffusion fuel cell

    SciTech Connect

    Struthers, R.C.

    1987-08-04

    This patent describes a fuel cell comprising; an elongate case; a thin, flat separator part of non-porous, di-electric, hydrogen-permeable material between the ends of and extending transverse the case and defining anode and cathode chambers; a thin, flat anode part of non-porous, electric conductive, hydrogen-permeable metallic material in the anode chamber in flat contacting engagement with and co-extensive with the separator part; a flat, porous, catalytic cathode part in the cathode chamber in contacting engagement with the separator part; hydrogen supply means supplying hydrogen to the anode part within the anode chamber; oxidant gas supply means supplying oxidant gas to the cathode part within the cathode chamber; and, an external electric circuit connected with and between the anode and cathode parts. The anode part absorbs and is permeated by hydrogen supplied to it and diffuses the hydrogen to hydrogen ions and free electrons; the free electrons in the anode part are conducted from the anode part into the electric circuit to perform useful work. The hydrogen ions in the anode part move from the anode part through the separator part and into the cathode part. Free electrons are conducted by the electric circuit into the cathode part. The hydrogen ions, oxidant gas and free electrons in the cathode part react and generate waste, heat and water.

  10. Diffuse gamma radiation

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Simpson, G. A.; Thompson, D. J.

    1977-01-01

    An examination of the intensity, energy spectrum, and spatial distribution of the diffuse gamma-radiation observed by SAS-2 satellite away from the galactic plane in the energy range above 35 MeV has shown that it consists of two components. One component is generally correlated with galactic latitudes, the atomic hydrogen column density was deduced from 21 cm measurements, and the continuum radio emission, believed to be synchrotron emission. It has an energy spectrum similar to that in the plane and joins smoothly to the intense radiation from the plane. It is therefore presumed to be of galactic origin. The other component is apparently isotropic, at least on a coarse scale, and has a steep energy spectrum. No evidence is found for a cosmic ray halo surrounding the galaxy in the shape of a sphere or oblate spheroid with galactic dimensions. Constraints for a halo model with significantly larger dimensions are set on the basis of an upper limit to the gamma-ray anisotropy.

  11. Handheld Diffusion Test Cells

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This photo shows the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells (inside the plastic box) will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

  12. Facilitation and inhibition in attention: Functional dissociation of pre-stimulus alpha activity, P1, and N1 components.

    PubMed

    Slagter, H A; Prinssen, S; Reteig, L C; Mazaheri, A

    2016-01-15

    Attention--the ability to attend to some things while ignoring others - can be best described as an emergent property of many neural mechanisms, facilitatory and inhibitory, working together to resolve competition for processing resources and control of behavior. Previous EEG and MEG studies examining the neural mechanisms underlying facilitation and inhibition of stimulus processing typically used paradigms requiring alternating shifts of attention in the spatial domain, with stimuli occurring at both attended and unattended locations. These studies generally observed greater pre-stimulus alpha oscillations over task-irrelevant vs. relevant posterior regions and bilateral attentional modulations of early sensory processing. In contrast, in the current series of experiments, participants continuously attended to only one hemifield and stimuli were only presented at the attended location, affording us an opportunity to elucidate the inhibitory and facilitatory effects of attention in the brain in a context in which spatial relevance was fixed. We found that continuous attention to one hemifield did not modulate prestimulus alpha activity in ipsilateral regions but did result in a perfectly lateralized P1 attention effect to ipsilateral posterior regions. Moreover, we found a bilateral N1 effect. These findings suggest that pre-stimulus alpha activity, the P1 and the N1 reflect qualitatively different aspects of attention; While pre-stimulus alpha-band activity may reflect a top-down inhibitory mechanism that critically depends on functional competition between task-relevant and irrelevant sensory regions, the ipsilateral P1 effect may reflect stimulus-triggered blocking of sensory processing in irrelevant networks, and the N1 effect facilitation of task-relevant processing. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Major grass pollen allergen Lol p 1 binds to diesel exhaust particles: implications for asthma and air pollution.

    PubMed

    Knox, R B; Suphioglu, C; Taylor, P; Desai, R; Watson, H C; Peng, J L; Bursill, L A

    1997-03-01

    Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 microns in diameter) to smaller size fractions < 2.5 microns (fine particles, PM25). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution. We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air. We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron-microscopic imaging technique. DECP are visualized as small carbon spheres, each 30-60 nm in diameter, forming fractal aggregates about 1-2 microns in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p 1, binds to one defined class of fine particles, DECP. DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p 1 under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

  14. Discovery of a potential lead compound for treating leprosy with dapsone resistance mutation in M. leprae folP1.

    PubMed

    Nisha, J; Ramanathan, K; Nawaz Khan, F; Dhanasekaran, D; Shanthi, V

    2016-06-21

    Dapsone resistance is a serious impediment to the implementation of the present leprosy control strategies. In the recent past, many studies have been undertaken to address the antibiotic activity and binding pattern of dapsone against both native and mutant (Pro55Leu) folP1. Yet, there is no well-developed structural basis for understanding drug action and there is dire need for new antibacterial therapies. In the present study, molecular simulation techniques were employed alongside experimental strategies to address and overcome the mechanism of dapsone resistance. In essence, we report the identification of small molecule compounds to effectively and specifically inhibit the growth of M. leprae through targeting dihydropteroate synthase, encoded by folP1 which is involved in folic acid synthesis. Initially, ADME and toxicity studies were employed to screen the lead compounds, using dapsone as standard drug. Subsequently, molecular docking was employed to understand the binding efficiency of dapsone and its lead compounds against folP1. Further, the activity of the screened lead molecule was studied by means of molecular dynamics simulation techniques. Furthermore, we synthesized 4-(2-fluorophenylsulfonyl)benzenamine, using (2-fluorophenyl)boronic acid and 4-aminobenzenesulfonyl chloride, and the compound structure was confirmed by (1)H NMR and (13)C NMR spectroscopic techniques. Most importantly, the antibacterial activity of the compound was also examined and compared against dapsone. Overall, the result from our analysis suggested that CID21480113 (4-(2-fluorophenylsulfonyl)benzenamine) could be developed into a promising lead compound and could be effective in treating dapsone resistant leprosy cases.

  15. Evaluation of a diverse set of potential P1 carboxylic acid bioisosteres in hepatitis C virus NS3 protease inhibitors.

    PubMed

    Rönn, Robert; Gossas, Thomas; Sabnis, Yogesh A; Daoud, Hanna; Kerblom, Eva; Danielson, U Helena; Sandström, Anja

    2007-06-15

    There is an urgent need for more efficient therapies for people infected with hepatitis C virus (HCV). HCV NS3 protease inhibitors have shown proof-of-concept in clinical trials, which make the virally encoded NS3 protease an attractive drug target. Product-based NS3 protease inhibitors comprising a P1 C-terminal carboxylic acid have shown to be effective and we were interested in finding alternatives to this crucial carboxylic acid group. Thus, a series of diverse P1 functional groups with different acidity and with possibilities to form a similar, or an even more powerful, hydrogen bond network as compared to the carboxylic acid were synthesized and incorporated into potential inhibitors of the NS3 protease. Biochemical evaluation of the inhibitors was performed in both enzyme and cell-based assays. Several non-acidic C-terminal groups, such as amides and hydrazides, were evaluated but failed to produce inhibitors more potent than the corresponding carboxylic acid inhibitor. The tetrazole moiety, although of similar acidity to a carboxylic acid, provided an inhibitor with mediocre potencies in both assays. However, the acyl cyanamide and the acyl sulfinamide groups rendered compounds with low nanomolar inhibitory potencies and were more potent than the corresponding carboxylic acid inhibitor in the enzymatic assay. Additionally, results from a pH-study suggest that the P(1) C-terminal of the inhibitors comprising a carboxylic acid, an acyl sulfonamide or an acyl cyanamide group binds in a similar mode in the active site of the NS3 protease.

  16. Characterization of Mn-doped In(1-x)Ga(x)As(y)P(1-y) grown by LPEE

    NASA Technical Reports Server (NTRS)

    Iyer, Shanthi N.; Abul-Fadl, Ali; Collis, Ward J.; Khorrami, Mohammad N.

    1988-01-01

    Mn-doped In(1-x)Ga(x)As(y)P(1-y) epilayers lattice matched to InP substrate have been grown by the liquid phase electroepitaxial (LPEE) technique. The variation of growth velocity of the epilayers with current density and the doping characteristics of Mn in the epilayer has been studied. The temperature dependence of the hole concentration and the mobility has been analyzed to determine the donor and acceptor densities, thermal activation energy of the level associated with Mn and the dominant scattering mechanisms that limit the hole mobility. The photoluminescence spectra of the doped epilayers are examined at 10 K as a function of the excitation level.

  17. Late-stage optimization of a tercyclic class of S1P3-sparing, S1P1 receptor agonists.

    PubMed

    Horan, Joshua C; Kuzmich, Daniel; Liu, Pingrong; DiSalvo, Darren; Lord, John; Mao, Can; Hopkins, Tamara D; Yu, Hui; Harcken, Christian; Betageri, Raj; Hill-Drzewi, Melissa; Patenaude, Lori; Patel, Monica; Fletcher, Kimberly; Terenzzio, Donna; Linehan, Brian; Xia, Heather; Patel, Mita; Studwell, Debbie; Miller, Craig; Hickey, Eugene; Levin, Jeremy I; Smith, Dustin; Kemper, Raymond A; Modis, Louise K; Bannen, Lynne C; Chan, Diva S; Mac, Morrison B; Ng, Stephanie; Wang, Yong; Xu, Wei; Lemieux, René M

    2016-01-15

    Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders.

  18. Roles of Long and Short Replication Initiation Proteins in the Fate of IncP-1 Plasmids

    PubMed Central

    Yano, Hirokazu; Deckert, Gail E.; Rogers, Linda M.

    2012-01-01

    Broad-host-range IncP-1 plasmids generally encode two replication initiation proteins, TrfA1 and TrfA2. TrfA2 is produced from an internal translational start site within trfA1. While TrfA1 was previously shown to be essential for replication in Pseudomonas aeruginosa, its role in other bacteria within its broad host range has not been established. To address the role of TrfA1 and TrfA2 in other hosts, efficiency of transformation, plasmid copy number (PCN), and plasmid stability were first compared between a mini-IncP-1β plasmid and its trfA1 frameshift variant in four phylogenetically distant hosts: Escherichia coli, Pseudomonas putida, Sphingobium japonicum, and Cupriavidus necator. TrfA2 was sufficient for replication in these hosts, but the presence of TrfA1 enhanced transformation efficiency and PCN. However, TrfA1 did not contribute to, and even negatively affected, long-term plasmid persistence. When trfA genes were cloned under a constitutive promoter in the chromosomes of the four hosts, strains expressing either both TrfA1 and TrfA2 or TrfA1 alone, again, generally elicited a higher PCN of an IncP1-β replicon than strains expressing TrfA2 alone. When a single species of TrfA was produced at different concentrations in E. coli cells, TrfA1 maintained a 3- to 4-fold higher PCN than TrfA2 at the same TrfA concentrations, indicating that replication mediated by TrfA1 is more efficient than that by TrfA2. These results suggest that the broad-host-range properties of IncP-1 plasmids are essentially conferred by TrfA2 and the intact replication origin alone but that TrfA1 is nonetheless important to efficiently establish plasmid replication upon transfer into a broad range of hosts. PMID:22228734

  19. Effect of rapid thermal annealing on InP1-xBix grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Wu, X. Y.; Wang, K.; Pan, W. W.; Wang, P.; Li, Y. Y.; Song, Y. X.; Gu, Y.; Yue, L.; Xu, H.; Zhang, Z. P.; Cui, J.; Gong, Q.; Wang, S. M.

    2015-09-01

    The effect of post-growth rapid thermal annealing on structural and optical properties of InP1-xBix thin films was investigated. InPBi shows good thermal stability up to 500 °C and a modest improvement in photoluminescence (PL) intensity with an unchanged PL spectral feature. Bismuth outdiffusion from InPBi and strain relaxation are observed at about 600 °C. The InPBi sample annealed at 800 °C shows an unexpected PL spectrum with different energy transitions.

  20. The effect of doping on magnetic properties of (Fe1-xMnx)2P1-ySiy series

    NASA Astrophysics Data System (ADS)

    Goraus, Jerzy; Hawełek, Lukasz; Włodarczyk, Patryk

    2015-12-01

    In this paper we present results of ab initio calculations for the (Fe1-xMnx)2P1-ySiy series, where we investigate the effect of doping on magnetic properties of these materials. Such compounds, which belong to the Fe2 P class of magnetocaloric materials are now extensively studied, due to their potential applications in magnetic cooling. In the hexagonal Fe2 P-type structure, transition metals occupy two inequivalent Wyckoff positions: 3 f and 3 g. We have shown that the preference of occupation of one site by the particular transition metal leads to different dependence of magnetic properties with respect to the total doping effect.